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rippled/src/test/app/Loan_test.cpp

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#include <xrpl/beast/unit_test/suite.h>
//
#include <test/jtx.h>
#include <test/jtx/mpt.h>
#include <xrpl/beast/xor_shift_engine.h>
#include <xrpl/protocol/SField.h>
#include <xrpl/server/LoadFeeTrack.h>
#include <xrpl/tx/transactors/lending/LendingHelpers.h>
#include <xrpl/tx/transactors/lending/LoanSet.h>
#include <xrpl/tx/transactors/system/Batch.h>
#include <chrono>
namespace xrpl {
namespace test {
class Loan_test : public beast::unit_test::suite
{
protected:
// Ensure that all the features needed for Lending Protocol are included,
// even if they are set to unsupported.
FeatureBitset const all{
jtx::testable_amendments() | featureMPTokensV1 | featureSingleAssetVault |
featureLendingProtocol};
std::string const iouCurrency{"IOU"};
void
testDisabled()
{
testcase("Disabled");
// Lending Protocol depends on Single Asset Vault (SAV). Test
// combinations of the two amendments.
// Single Asset Vault depends on MPTokensV1, but don't test every combo
// of that.
using namespace jtx;
auto failAll = [this](FeatureBitset features) {
Env env(*this, features);
Account const alice{"alice"};
Account const bob{"bob"};
env.fund(XRP(10000), alice, bob);
auto const keylet = keylet::loanbroker(alice, env.seq(alice));
using namespace std::chrono_literals;
using namespace loan;
// counter party signature is optional on LoanSet. Confirm that by
// sending transaction without one.
auto setTx = env.jt(set(alice, keylet.key, Number(10000)), ter(temDISABLED));
env(setTx);
// All loan transactions are disabled.
// 1. LoanSet
setTx = env.jt(setTx, sig(sfCounterpartySignature, bob), ter(temDISABLED));
env(setTx);
// Actual sequence will be based off the loan broker, but we
// obviously don't have one of those if the amendment is disabled
auto const loanKeylet = keylet::loan(keylet.key, env.seq(alice));
// Other Loan transactions are disabled, too.
// 2. LoanDelete
env(del(alice, loanKeylet.key), ter(temDISABLED));
// 3. LoanManage
env(manage(alice, loanKeylet.key, tfLoanImpair), ter(temDISABLED));
// 4. LoanPay
env(pay(alice, loanKeylet.key, XRP(500)), ter(temDISABLED));
};
failAll(all - featureMPTokensV1);
failAll(all - featureSingleAssetVault - featureLendingProtocol);
failAll(all - featureSingleAssetVault);
failAll(all - featureLendingProtocol);
}
struct BrokerParameters
{
Number vaultDeposit = 1'000'000;
Number debtMax = 25'000;
TenthBips32 coverRateMin = percentageToTenthBips(10);
int coverDeposit = 1000;
TenthBips16 managementFeeRate{100};
TenthBips32 coverRateLiquidation = percentageToTenthBips(25);
std::string data = {}; // NOLINT(readability-redundant-member-init)
std::uint32_t flags = 0;
Number
maxCoveredLoanValue(Number const& currentDebt) const
{
NumberRoundModeGuard mg(Number::downward);
auto debtLimit = coverDeposit * tenthBipsPerUnity.value() / coverRateMin.value();
return debtLimit - currentDebt;
}
static BrokerParameters const&
defaults()
{
static BrokerParameters const result{};
return result;
}
// TODO: create an operator() which returns a transaction similar to
// LoanParameters
};
struct BrokerInfo
{
jtx::PrettyAsset asset;
uint256 brokerID;
uint256 vaultID;
BrokerParameters params;
BrokerInfo(
jtx::PrettyAsset const& asset_,
Keylet const& brokerKeylet_,
Keylet const& vaultKeylet_,
BrokerParameters const& p)
: asset(asset_), brokerID(brokerKeylet_.key), vaultID(vaultKeylet_.key), params(p)
{
}
Keylet
brokerKeylet() const
{
return keylet::loanbroker(brokerID);
}
Keylet
vaultKeylet() const
{
return keylet::vault(vaultID);
}
int
vaultScale(jtx::Env const& env) const
{
using namespace jtx;
auto const vaultSle = env.le(keylet::vault(vaultID));
return getAssetsTotalScale(vaultSle);
}
};
struct LoanParameters
{
// The account submitting the transaction. May be borrower or broker.
jtx::Account account;
// The counterparty. Should be the other of borrower or broker.
jtx::Account counter;
// Whether the counterparty is specified in the `counterparty` field, or
// only signs.
bool counterpartyExplicit = true;
Number principalRequest;
// NOLINTBEGIN(readability-redundant-member-init)
std::optional<STAmount> setFee = std::nullopt;
std::optional<Number> originationFee = std::nullopt;
std::optional<Number> serviceFee = std::nullopt;
std::optional<Number> lateFee = std::nullopt;
std::optional<Number> closeFee = std::nullopt;
std::optional<TenthBips32> overFee = std::nullopt;
std::optional<TenthBips32> interest = std::nullopt;
std::optional<TenthBips32> lateInterest = std::nullopt;
std::optional<TenthBips32> closeInterest = std::nullopt;
std::optional<TenthBips32> overpaymentInterest = std::nullopt;
std::optional<std::uint32_t> payTotal = std::nullopt;
std::optional<std::uint32_t> payInterval = std::nullopt;
std::optional<std::uint32_t> gracePd = std::nullopt;
std::optional<std::uint32_t> flags = std::nullopt;
// NOLINTEND(readability-redundant-member-init)
template <class... FN>
jtx::JTx
operator()(jtx::Env& env, BrokerInfo const& broker, FN const&... fN) const
{
using namespace jtx;
using namespace jtx::loan;
JTx jt{loan::set(
account,
broker.brokerID,
broker.asset(principalRequest).number(),
flags.value_or(0))};
sig(sfCounterpartySignature, counter)(env, jt);
fee{setFee.value_or(env.current()->fees().base * 2)}(env, jt);
if (counterpartyExplicit)
counterparty(counter)(env, jt);
if (originationFee)
loanOriginationFee(broker.asset(*originationFee).number())(env, jt);
if (serviceFee)
loanServiceFee(broker.asset(*serviceFee).number())(env, jt);
if (lateFee)
latePaymentFee(broker.asset(*lateFee).number())(env, jt);
if (closeFee)
closePaymentFee(broker.asset(*closeFee).number())(env, jt);
if (overFee)
overpaymentFee (*overFee)(env, jt);
if (interest)
interestRate (*interest)(env, jt);
if (lateInterest)
lateInterestRate (*lateInterest)(env, jt);
if (closeInterest)
closeInterestRate (*closeInterest)(env, jt);
if (overpaymentInterest)
overpaymentInterestRate (*overpaymentInterest)(env, jt);
if (payTotal)
paymentTotal (*payTotal)(env, jt);
if (payInterval)
paymentInterval (*payInterval)(env, jt);
if (gracePd)
gracePeriod (*gracePd)(env, jt);
return env.jt(jt, fN...);
}
};
struct PaymentParameters
{
Number overpaymentFactor = Number{1};
std::optional<Number> overpaymentExtra = std::nullopt;
std::uint32_t flags = 0;
bool showStepBalances = false;
bool validateBalances = true;
static PaymentParameters const&
defaults()
{
static PaymentParameters const result{};
return result;
}
};
struct LoanState
{
std::uint32_t previousPaymentDate = 0;
NetClock::time_point startDate;
std::uint32_t nextPaymentDate = 0;
std::uint32_t paymentRemaining = 0;
std::int32_t const loanScale = 0;
Number totalValue = 0;
Number principalOutstanding = 0;
Number managementFeeOutstanding = 0;
Number periodicPayment = 0;
std::uint32_t flags = 0;
std::uint32_t const paymentInterval = 0;
TenthBips32 const interestRate{};
};
/** Helper class to compare the expected state of a loan and loan broker
* against the data in the ledger.
*/
struct VerifyLoanStatus
{
public:
jtx::Env const& env;
BrokerInfo const& broker;
jtx::Account const& pseudoAccount;
Keylet const& loanKeylet;
VerifyLoanStatus(
jtx::Env const& env_,
BrokerInfo const& broker_,
jtx::Account const& pseudo_,
Keylet const& keylet_)
: env(env_), broker(broker_), pseudoAccount(pseudo_), loanKeylet(keylet_)
{
}
/** Checks the expected broker state against the ledger
*/
void
checkBroker(
Number const& principalOutstanding,
Number const& interestOwed,
TenthBips32 interestRate,
std::uint32_t paymentInterval,
std::uint32_t paymentsRemaining,
std::uint32_t ownerCount) const
{
using namespace jtx;
if (auto brokerSle = env.le(keylet::loanbroker(broker.brokerID));
env.test.BEAST_EXPECT(brokerSle))
{
TenthBips16 const managementFeeRate{brokerSle->at(sfManagementFeeRate)};
auto const brokerDebt = brokerSle->at(sfDebtTotal);
auto const expectedDebt = principalOutstanding + interestOwed;
env.test.BEAST_EXPECT(brokerDebt == expectedDebt);
env.test.BEAST_EXPECT(
env.balance(pseudoAccount, broker.asset).number() ==
brokerSle->at(sfCoverAvailable));
env.test.BEAST_EXPECT(brokerSle->at(sfOwnerCount) == ownerCount);
if (auto vaultSle = env.le(keylet::vault(brokerSle->at(sfVaultID)));
env.test.BEAST_EXPECT(vaultSle))
{
Account const vaultPseudo{"vaultPseudoAccount", vaultSle->at(sfAccount)};
env.test.BEAST_EXPECT(
vaultSle->at(sfAssetsAvailable) ==
env.balance(vaultPseudo, broker.asset).number());
if (ownerCount == 0)
{
// Allow some slop for rounding IOUs
// TODO: This needs to be an exact match once all the
// other rounding issues are worked out.
auto const total = vaultSle->at(sfAssetsTotal);
auto const available = vaultSle->at(sfAssetsAvailable);
env.test.BEAST_EXPECT(
total == available ||
(!broker.asset.integral() && available != 0 &&
((total - available) / available < Number(1, -6))));
env.test.BEAST_EXPECT(vaultSle->at(sfLossUnrealized) == 0);
}
}
}
}
void
checkPayment(
std::int32_t loanScale,
jtx::Account const& account,
jtx::PrettyAmount const& balanceBefore,
STAmount const& expectedPayment,
jtx::PrettyAmount const& adjustment) const
{
auto const borrowerScale = std::max(loanScale, balanceBefore.number().exponent());
STAmount const balanceChangeAmount{
broker.asset,
roundToAsset(broker.asset, expectedPayment + adjustment, borrowerScale)};
{
auto const difference = roundToScale(
env.balance(account, broker.asset) - (balanceBefore - balanceChangeAmount),
borrowerScale);
env.test.expect(
roundToScale(difference, loanScale) >= beast::zero,
"Balance before: " + to_string(balanceBefore.value()) +
", expected change: " + to_string(balanceChangeAmount) +
", difference (balance after - expected): " + to_string(difference),
__FILE__,
__LINE__);
}
}
/** Checks both the loan and broker expect states against the ledger */
void
operator()(
std::uint32_t previousPaymentDate,
std::uint32_t nextPaymentDate,
std::uint32_t paymentRemaining,
Number const& loanScale,
Number const& totalValue,
Number const& principalOutstanding,
Number const& managementFeeOutstanding,
Number const& periodicPayment,
std::uint32_t flags) const
{
using namespace jtx;
if (auto loan = env.le(loanKeylet); env.test.BEAST_EXPECT(loan))
{
env.test.BEAST_EXPECT(loan->at(sfPreviousPaymentDueDate) == previousPaymentDate);
env.test.BEAST_EXPECT(loan->at(sfPaymentRemaining) == paymentRemaining);
env.test.BEAST_EXPECT(loan->at(sfNextPaymentDueDate) == nextPaymentDate);
env.test.BEAST_EXPECT(loan->at(sfLoanScale) == loanScale);
env.test.BEAST_EXPECT(loan->at(sfTotalValueOutstanding) == totalValue);
env.test.BEAST_EXPECT(loan->at(sfPrincipalOutstanding) == principalOutstanding);
env.test.BEAST_EXPECT(
loan->at(sfManagementFeeOutstanding) == managementFeeOutstanding);
env.test.BEAST_EXPECT(loan->at(sfPeriodicPayment) == periodicPayment);
env.test.BEAST_EXPECT(loan->at(sfFlags) == flags);
auto const ls = constructRoundedLoanState(loan);
auto const interestRate = TenthBips32{loan->at(sfInterestRate)};
auto const paymentInterval = loan->at(sfPaymentInterval);
checkBroker(
principalOutstanding,
ls.interestDue,
interestRate,
paymentInterval,
paymentRemaining,
1);
if (auto brokerSle = env.le(keylet::loanbroker(broker.brokerID));
env.test.BEAST_EXPECT(brokerSle))
{
if (auto vaultSle = env.le(keylet::vault(brokerSle->at(sfVaultID)));
env.test.BEAST_EXPECT(vaultSle))
{
if (((flags & lsfLoanImpaired) != 0u) && ((flags & lsfLoanDefault) == 0u))
{
env.test.BEAST_EXPECT(
vaultSle->at(sfLossUnrealized) ==
totalValue - managementFeeOutstanding);
}
else
{
env.test.BEAST_EXPECT(vaultSle->at(sfLossUnrealized) == 0);
}
}
}
}
}
/** Checks both the loan and broker expect states against the ledger */
void
operator()(LoanState const& state) const
{
operator()(
state.previousPaymentDate,
state.nextPaymentDate,
state.paymentRemaining,
state.loanScale,
state.totalValue,
state.principalOutstanding,
state.managementFeeOutstanding,
state.periodicPayment,
state.flags);
};
};
BrokerInfo
createVaultAndBroker(
jtx::Env& env,
jtx::PrettyAsset const& asset,
jtx::Account const& lender,
BrokerParameters const& params = BrokerParameters::defaults())
{
using namespace jtx;
Vault vault{env};
auto const deposit = asset(params.vaultDeposit);
auto const debtMaximumValue = asset(params.debtMax).value();
auto const coverDepositValue = asset(params.coverDeposit).value();
auto const coverRateMinValue = params.coverRateMin;
auto [tx, vaultKeylet] = vault.create({.owner = lender, .asset = asset});
env(tx);
env.close();
BEAST_EXPECT(env.le(vaultKeylet));
env(vault.deposit({.depositor = lender, .id = vaultKeylet.key, .amount = deposit}));
env.close();
if (auto const vault = env.le(keylet::vault(vaultKeylet.key)); BEAST_EXPECT(vault))
{
BEAST_EXPECT(vault->at(sfAssetsAvailable) == deposit.value());
}
auto const keylet = keylet::loanbroker(lender.id(), env.seq(lender));
using namespace loanBroker;
env(set(lender, vaultKeylet.key, params.flags),
data(params.data),
managementFeeRate(params.managementFeeRate),
debtMaximum(debtMaximumValue),
coverRateMinimum(coverRateMinValue),
coverRateLiquidation(TenthBips32(params.coverRateLiquidation)));
if (coverDepositValue != beast::zero)
env(coverDeposit(lender, keylet.key, coverDepositValue));
env.close();
return {asset, keylet, vaultKeylet, params};
}
/// Get the state without checking anything
LoanState
getCurrentState(jtx::Env const& env, BrokerInfo const& broker, Keylet const& loanKeylet)
{
using d = NetClock::duration;
using tp = NetClock::time_point;
// Lookup the current loan state
if (auto loan = env.le(loanKeylet); BEAST_EXPECT(loan))
{
return LoanState{
.previousPaymentDate = loan->at(sfPreviousPaymentDueDate),
.startDate = tp{d{loan->at(sfStartDate)}},
.nextPaymentDate = loan->at(sfNextPaymentDueDate),
.paymentRemaining = loan->at(sfPaymentRemaining),
.loanScale = loan->at(sfLoanScale),
.totalValue = loan->at(sfTotalValueOutstanding),
.principalOutstanding = loan->at(sfPrincipalOutstanding),
.managementFeeOutstanding = loan->at(sfManagementFeeOutstanding),
.periodicPayment = loan->at(sfPeriodicPayment),
.flags = loan->at(sfFlags),
.paymentInterval = loan->at(sfPaymentInterval),
.interestRate = TenthBips32{loan->at(sfInterestRate)},
};
}
return LoanState{};
}
/// Get the state and check the values against the parameters used in
/// `lifecycle`
LoanState
getCurrentState(
jtx::Env const& env,
BrokerInfo const& broker,
Keylet const& loanKeylet,
VerifyLoanStatus const& verifyLoanStatus)
{
using namespace std::chrono_literals;
using d = NetClock::duration;
using tp = NetClock::time_point;
auto const state = getCurrentState(env, broker, loanKeylet);
BEAST_EXPECT(state.previousPaymentDate == 0);
BEAST_EXPECT(tp{d{state.nextPaymentDate}} == state.startDate + 600s);
BEAST_EXPECT(state.paymentRemaining == 12);
BEAST_EXPECT(state.principalOutstanding == broker.asset(1000).value());
BEAST_EXPECT(
state.loanScale >=
(broker.asset.integral()
? 0
: std::max(broker.vaultScale(env), state.principalOutstanding.exponent())));
BEAST_EXPECT(state.paymentInterval == 600);
{
NumberRoundModeGuard mg(Number::upward);
BEAST_EXPECT(
state.totalValue ==
roundToAsset(
broker.asset, state.periodicPayment * state.paymentRemaining, state.loanScale));
}
BEAST_EXPECT(
state.managementFeeOutstanding ==
computeManagementFee(
broker.asset,
state.totalValue - state.principalOutstanding,
broker.params.managementFeeRate,
state.loanScale));
verifyLoanStatus(state);
return state;
}
bool
canImpairLoan(jtx::Env const& env, BrokerInfo const& broker, LoanState const& state)
{
if (auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle))
{
if (auto const vaultSle = env.le(keylet::vault(brokerSle->at(sfVaultID)));
BEAST_EXPECT(vaultSle))
{
// log << vaultSle->getJson() << std::endl;
auto const assetsUnavailable =
vaultSle->at(sfAssetsTotal) - vaultSle->at(sfAssetsAvailable);
auto const unrealizedLoss = vaultSle->at(sfLossUnrealized) + state.totalValue -
state.managementFeeOutstanding;
if (!BEAST_EXPECT(unrealizedLoss <= assetsUnavailable))
{
return false;
}
}
}
return true;
}
enum class AssetType { XRP = 0, IOU = 1, MPT = 2 };
// Specify the accounts as params to allow other accounts to be used
jtx::PrettyAsset
createAsset(
jtx::Env& env,
AssetType assetType,
BrokerParameters const& brokerParams,
jtx::Account const& issuer,
jtx::Account const& lender,
jtx::Account const& borrower)
{
using namespace jtx;
switch (assetType)
{
case AssetType::XRP:
// TODO: remove the factor, and set up loans in drops
return PrettyAsset{xrpIssue(), 1'000'000};
case AssetType::IOU: {
PrettyAsset const asset{issuer[iouCurrency]};
auto const limit =
asset(100 * (brokerParams.vaultDeposit + brokerParams.coverDeposit));
if (lender != issuer)
env(trust(lender, limit));
if (borrower != issuer)
env(trust(borrower, limit));
return asset;
}
case AssetType::MPT: {
// Enough to cover initial fees
if (!env.le(keylet::account(issuer)))
env.fund(env.current()->fees().accountReserve(10) * 10, issuer);
if (!env.le(keylet::account(lender)))
env.fund(env.current()->fees().accountReserve(10) * 10, noripple(lender));
if (!env.le(keylet::account(borrower)))
env.fund(env.current()->fees().accountReserve(10) * 10, noripple(borrower));
MPTTester mptt{env, issuer, mptInitNoFund};
mptt.create({.flags = tfMPTCanClawback | tfMPTCanTransfer | tfMPTCanLock});
// Scale the MPT asset so interest is interesting
PrettyAsset const asset{mptt.issuanceID(), 10'000};
// Need to do the authorization here because mptt isn't
// accessible outside
if (lender != issuer)
mptt.authorize({.account = lender});
if (borrower != issuer)
mptt.authorize({.account = borrower});
env.close();
return asset;
}
default:
throw std::runtime_error("Unknown asset type");
}
}
void
describeLoan(
jtx::Env& env,
BrokerParameters const& brokerParams,
LoanParameters const& loanParams,
AssetType assetType,
jtx::Account const& issuer,
jtx::Account const& lender,
jtx::Account const& borrower)
{
using namespace jtx;
auto const asset = createAsset(env, assetType, brokerParams, issuer, lender, borrower);
auto const principal = asset(loanParams.principalRequest).number();
auto const interest = loanParams.interest.value_or(TenthBips32{});
auto const interval = loanParams.payInterval.value_or(LoanSet::defaultPaymentInterval);
auto const total = loanParams.payTotal.value_or(LoanSet::defaultPaymentTotal);
auto const feeRate = brokerParams.managementFeeRate;
auto const props = computeLoanProperties(
asset,
principal,
interest,
interval,
total,
feeRate,
asset(brokerParams.vaultDeposit).number().exponent());
log << "Loan properties:\n"
<< "\tPrincipal: " << principal << std::endl
<< "\tInterest rate: " << interest << std::endl
<< "\tPayment interval: " << interval << std::endl
<< "\tManagement Fee Rate: " << feeRate << std::endl
<< "\tTotal Payments: " << total << std::endl
<< "\tPeriodic Payment: " << props.periodicPayment << std::endl
<< "\tTotal Value: " << props.loanState.valueOutstanding << std::endl
<< "\tManagement Fee: " << props.loanState.managementFeeDue << std::endl
<< "\tLoan Scale: " << props.loanScale << std::endl
<< "\tFirst payment principal: " << props.firstPaymentPrincipal << std::endl;
// checkGuards returns a TER, so success is 0
BEAST_EXPECT(!checkLoanGuards(
asset,
asset(loanParams.principalRequest).number(),
loanParams.interest.value_or(TenthBips32{}) != beast::zero,
loanParams.payTotal.value_or(LoanSet::defaultPaymentTotal),
props,
env.journal));
}
std::optional<std::tuple<BrokerInfo, Keylet, jtx::Account>>
createLoan(
jtx::Env& env,
AssetType assetType,
BrokerParameters const& brokerParams,
LoanParameters const& loanParams,
jtx::Account const& issuer,
jtx::Account const& lender,
jtx::Account const& borrower)
{
using namespace jtx;
// Enough to cover initial fees
env.fund(env.current()->fees().accountReserve(10) * 10, issuer);
if (lender != issuer)
env.fund(env.current()->fees().accountReserve(10) * 10, noripple(lender));
if (borrower != issuer && borrower != lender)
env.fund(env.current()->fees().accountReserve(10) * 10, noripple(borrower));
describeLoan(env, brokerParams, loanParams, assetType, issuer, lender, borrower);
// Make the asset
auto const asset = createAsset(env, assetType, brokerParams, issuer, lender, borrower);
env.close();
if (asset.native() || lender != issuer)
{
env(
pay((asset.native() ? env.master : issuer),
lender,
asset(brokerParams.vaultDeposit + brokerParams.coverDeposit)));
}
// Fund the borrower later once we know the total loan
// size
BrokerInfo const broker = createVaultAndBroker(env, asset, lender, brokerParams);
auto const pseudoAcctOpt = [&]() -> std::optional<Account> {
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
return std::nullopt;
auto const brokerPseudo = brokerSle->at(sfAccount);
return Account("Broker pseudo-account", brokerPseudo);
}();
if (!pseudoAcctOpt)
return std::nullopt;
Account const& pseudoAcct = *pseudoAcctOpt;
auto const loanKeyletOpt = [&]() -> std::optional<Keylet> {
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
return std::nullopt;
// Broker has no loans
BEAST_EXPECT(brokerSle->at(sfOwnerCount) == 0);
// The loan keylet is based on the LoanSequence of the
// _LOAN_BROKER_ object.
auto const loanSequence = brokerSle->at(sfLoanSequence);
return keylet::loan(broker.brokerID, loanSequence);
}();
if (!loanKeyletOpt)
return std::nullopt;
Keylet const& loanKeylet = *loanKeyletOpt;
env(loanParams(env, broker));
env.close();
return std::make_tuple(broker, loanKeylet, pseudoAcct);
}
static void
topUpBorrower(
jtx::Env& env,
BrokerInfo const& broker,
jtx::Account const& issuer,
jtx::Account const& borrower,
LoanState const& state,
std::optional<Number> const& servFee)
{
using namespace jtx;
STAmount const serviceFee = broker.asset(servFee.value_or(0));
// Ensure the borrower has enough funds to make the payments
// (including tx fees, if necessary)
auto const borrowerBalance = env.balance(borrower, broker.asset);
auto const baseFee = env.current()->fees().base;
// Add extra for transaction fees and reserves, if appropriate, or a
// tiny amount for the extra paid in each transaction
auto const totalNeeded = state.totalValue + (serviceFee * state.paymentRemaining) +
(broker.asset.native()
? Number(
baseFee * state.paymentRemaining +
env.current()->fees().accountReserve(env.ownerCount(borrower)))
: broker.asset(15).number());
auto const shortage = totalNeeded - borrowerBalance.number();
if (shortage > beast::zero && (broker.asset.native() || issuer != borrower))
{
env(
pay((broker.asset.native() ? env.master : issuer),
borrower,
STAmount{broker.asset, shortage}));
}
}
void
makeLoanPayments(
jtx::Env& env,
BrokerInfo const& broker,
LoanParameters const& loanParams,
Keylet const& loanKeylet,
VerifyLoanStatus const& verifyLoanStatus,
jtx::Account const& issuer,
jtx::Account const& lender,
jtx::Account const& borrower,
PaymentParameters const& paymentParams = PaymentParameters::defaults())
{
// Make all the individual payments
using namespace jtx;
using namespace jtx::loan;
using namespace std::chrono_literals;
using d = NetClock::duration;
bool const showStepBalances = paymentParams.showStepBalances;
auto const currencyLabel = getCurrencyLabel(broker.asset);
auto const baseFee = env.current()->fees().base;
env.close();
auto state = getCurrentState(env, broker, loanKeylet);
verifyLoanStatus(state);
STAmount const serviceFee = broker.asset(loanParams.serviceFee.value_or(0));
topUpBorrower(env, broker, issuer, borrower, state, loanParams.serviceFee);
// Periodic payment amount will consist of
// 1. principal outstanding (1000)
// 2. interest interest rate (at 12%)
// 3. payment interval (600s)
// 4. loan service fee (2)
// Calculate these values without the helper functions
// to verify they're working correctly The numbers in
// the below BEAST_EXPECTs may not hold across assets.
auto const periodicRate = loanPeriodicRate(state.interestRate, state.paymentInterval);
STAmount const roundedPeriodicPayment{
broker.asset,
roundPeriodicPayment(broker.asset, state.periodicPayment, state.loanScale)};
if (!showStepBalances)
{
log << currencyLabel << " Payment components: "
<< "Payments remaining, "
<< "rawInterest, rawPrincipal, "
"rawMFee, "
<< "trackedValueDelta, trackedPrincipalDelta, "
"trackedInterestDelta, trackedMgmtFeeDelta, special"
<< std::endl;
}
// Include the service fee
STAmount const totalDue =
roundToScale(roundedPeriodicPayment + serviceFee, state.loanScale, Number::upward);
auto currentRoundedState = constructLoanState(
state.totalValue, state.principalOutstanding, state.managementFeeOutstanding);
{
auto const raw = computeTheoreticalLoanState(
state.periodicPayment,
periodicRate,
state.paymentRemaining,
broker.params.managementFeeRate);
if (showStepBalances)
{
log << currencyLabel << " Starting loan balances: "
<< "\n\tTotal value: " << currentRoundedState.valueOutstanding
<< "\n\tPrincipal: " << currentRoundedState.principalOutstanding
<< "\n\tInterest: " << currentRoundedState.interestDue
<< "\n\tMgmt fee: " << currentRoundedState.managementFeeDue
<< "\n\tPayments remaining " << state.paymentRemaining << std::endl;
}
else
{
log << currencyLabel << " Loan starting state: " << state.paymentRemaining << ", "
<< raw.interestDue << ", " << raw.principalOutstanding << ", "
<< raw.managementFeeDue << ", " << currentRoundedState.valueOutstanding << ", "
<< currentRoundedState.principalOutstanding << ", "
<< currentRoundedState.interestDue << ", "
<< currentRoundedState.managementFeeDue << std::endl;
}
}
// Try to pay a little extra to show that it's _not_
// taken
auto const extraAmount = paymentParams.overpaymentExtra
? broker.asset(*paymentParams.overpaymentExtra).value()
: std::min(broker.asset(10).value(), STAmount{broker.asset, totalDue / 20});
STAmount const transactionAmount =
STAmount{broker.asset, totalDue * paymentParams.overpaymentFactor} + extraAmount;
auto const borrowerInitialBalance = env.balance(borrower, broker.asset).number();
auto const initialState = state;
detail::PaymentComponents totalPaid{
.trackedValueDelta = 0, .trackedPrincipalDelta = 0, .trackedManagementFeeDelta = 0};
Number totalInterestPaid = 0;
Number totalFeesPaid = 0;
std::size_t totalPaymentsMade = 0;
xrpl::LoanState currentTrueState = computeTheoreticalLoanState(
state.periodicPayment,
periodicRate,
state.paymentRemaining,
broker.params.managementFeeRate);
auto validateBorrowerBalance = [&]() {
if (borrower == issuer || !paymentParams.validateBalances)
return;
auto const totalSpent =
(totalPaid.trackedValueDelta + totalFeesPaid +
(broker.asset.native() ? Number(baseFee) * totalPaymentsMade : numZero));
BEAST_EXPECT(
env.balance(borrower, broker.asset).number() ==
borrowerInitialBalance - totalSpent);
};
auto const defaultRound = broker.asset.integral() ? 3 : 0;
auto truncate = [defaultRound](Number const& n, std::optional<int> places = std::nullopt) {
auto const p = places.value_or(defaultRound);
if (p == 0)
return n;
auto const factor = Number{1, p};
return (n * factor).truncate() / factor;
};
while (state.paymentRemaining > 0)
{
validateBorrowerBalance();
// Compute the expected principal amount
auto const paymentComponents = detail::computePaymentComponents(
broker.asset.raw(),
state.loanScale,
state.totalValue,
state.principalOutstanding,
state.managementFeeOutstanding,
state.periodicPayment,
periodicRate,
state.paymentRemaining,
broker.params.managementFeeRate);
BEAST_EXPECT(
paymentComponents.trackedValueDelta <= roundedPeriodicPayment ||
(paymentComponents.specialCase == detail::PaymentSpecialCase::final &&
paymentComponents.trackedValueDelta >= roundedPeriodicPayment));
BEAST_EXPECT(
paymentComponents.trackedValueDelta ==
paymentComponents.trackedPrincipalDelta + paymentComponents.trackedInterestPart() +
paymentComponents.trackedManagementFeeDelta);
xrpl::LoanState const nextTrueState = computeTheoreticalLoanState(
state.periodicPayment,
periodicRate,
state.paymentRemaining - 1,
broker.params.managementFeeRate);
detail::LoanStateDeltas const deltas = currentTrueState - nextTrueState;
BEAST_EXPECT(
deltas.total() == deltas.principal + deltas.interest + deltas.managementFee);
BEAST_EXPECT(
paymentComponents.specialCase == detail::PaymentSpecialCase::final ||
deltas.total() == state.periodicPayment ||
(state.loanScale - (deltas.total() - state.periodicPayment).exponent()) > 14);
if (!showStepBalances)
{
log << currencyLabel << " Payment components: " << state.paymentRemaining << ", "
<< deltas.interest << ", " << deltas.principal << ", " << deltas.managementFee
<< ", " << paymentComponents.trackedValueDelta << ", "
<< paymentComponents.trackedPrincipalDelta << ", "
<< paymentComponents.trackedInterestPart() << ", "
<< paymentComponents.trackedManagementFeeDelta << ", " << [&]() -> char const* {
if (paymentComponents.specialCase == detail::PaymentSpecialCase::final)
return "final";
if (paymentComponents.specialCase == detail::PaymentSpecialCase::extra)
return "extra";
return "none";
}() << std::endl;
}
auto const totalDueAmount =
STAmount{broker.asset, paymentComponents.trackedValueDelta + serviceFee};
if (paymentParams.validateBalances)
{
// Due to the rounding algorithms to keep the interest and
// principal in sync with "true" values, the computed amount
// may be a little less than the rounded fixed payment
// amount. For integral types, the difference should be < 3
// (1 unit for each of the interest and management fee). For
// IOUs, the difference should be dust.
Number const diff = totalDue - totalDueAmount;
BEAST_EXPECT(
paymentComponents.specialCase == detail::PaymentSpecialCase::final ||
diff == beast::zero ||
(diff > beast::zero &&
((broker.asset.integral() && (static_cast<Number>(diff) < 3)) ||
(state.loanScale - diff.exponent() > 13))));
BEAST_EXPECT(
paymentComponents.trackedPrincipalDelta >= beast::zero &&
paymentComponents.trackedPrincipalDelta <= state.principalOutstanding);
BEAST_EXPECT(
paymentComponents.specialCase != detail::PaymentSpecialCase::final ||
paymentComponents.trackedPrincipalDelta == state.principalOutstanding);
}
auto const borrowerBalanceBeforePayment = env.balance(borrower, broker.asset);
// Make the payment
env(pay(borrower, loanKeylet.key, transactionAmount, paymentParams.flags));
env.close(d{state.paymentInterval / 2});
if (paymentParams.validateBalances)
{
// Need to account for fees if the loan is in XRP
PrettyAmount adjustment = broker.asset(0);
if (broker.asset.native())
{
adjustment = env.current()->fees().base;
}
// Check the result
verifyLoanStatus.checkPayment(
state.loanScale,
borrower,
borrowerBalanceBeforePayment,
totalDueAmount,
adjustment);
}
if (showStepBalances)
{
auto const loanSle = env.le(loanKeylet);
if (!BEAST_EXPECT(loanSle))
{
// No reason for this not to exist
return;
}
auto const current = constructRoundedLoanState(loanSle);
auto const errors = nextTrueState - current;
log << currencyLabel << " Loan balances: "
<< "\n\tAmount taken: " << paymentComponents.trackedValueDelta
<< "\n\tTotal value: " << current.valueOutstanding
<< " (true: " << truncate(nextTrueState.valueOutstanding)
<< ", error: " << truncate(errors.total())
<< ")\n\tPrincipal: " << current.principalOutstanding
<< " (true: " << truncate(nextTrueState.principalOutstanding)
<< ", error: " << truncate(errors.principal)
<< ")\n\tInterest: " << current.interestDue
<< " (true: " << truncate(nextTrueState.interestDue)
<< ", error: " << truncate(errors.interest)
<< ")\n\tMgmt fee: " << current.managementFeeDue
<< " (true: " << truncate(nextTrueState.managementFeeDue)
<< ", error: " << truncate(errors.managementFee) << ")\n\tPayments remaining "
<< loanSle->at(sfPaymentRemaining) << std::endl;
currentRoundedState = current;
}
--state.paymentRemaining;
state.previousPaymentDate = state.nextPaymentDate;
if (paymentComponents.specialCase == detail::PaymentSpecialCase::final)
{
state.paymentRemaining = 0;
state.nextPaymentDate = 0;
}
else
{
state.nextPaymentDate += state.paymentInterval;
}
state.principalOutstanding -= paymentComponents.trackedPrincipalDelta;
state.managementFeeOutstanding -= paymentComponents.trackedManagementFeeDelta;
state.totalValue -= paymentComponents.trackedValueDelta;
if (paymentParams.validateBalances)
verifyLoanStatus(state);
totalPaid.trackedValueDelta += paymentComponents.trackedValueDelta;
totalPaid.trackedPrincipalDelta += paymentComponents.trackedPrincipalDelta;
totalPaid.trackedManagementFeeDelta += paymentComponents.trackedManagementFeeDelta;
totalInterestPaid += paymentComponents.trackedInterestPart();
totalFeesPaid += serviceFee;
++totalPaymentsMade;
currentTrueState = nextTrueState;
}
validateBorrowerBalance();
// Loan is paid off
BEAST_EXPECT(state.paymentRemaining == 0);
BEAST_EXPECT(state.principalOutstanding == 0);
auto const initialInterestDue = initialState.totalValue -
(initialState.principalOutstanding + initialState.managementFeeOutstanding);
if (paymentParams.validateBalances)
{
// Make sure all the payments add up
BEAST_EXPECT(totalPaid.trackedValueDelta == initialState.totalValue);
BEAST_EXPECT(totalPaid.trackedPrincipalDelta == initialState.principalOutstanding);
BEAST_EXPECT(
totalPaid.trackedManagementFeeDelta == initialState.managementFeeOutstanding);
// This is almost a tautology given the previous checks, but
// check it anyway for completeness.
BEAST_EXPECT(totalInterestPaid == initialInterestDue);
BEAST_EXPECT(totalPaymentsMade == initialState.paymentRemaining);
}
if (showStepBalances)
{
auto const loanSle = env.le(loanKeylet);
if (!BEAST_EXPECT(loanSle))
{
// No reason for this not to exist
return;
}
log << currencyLabel << " Total amounts paid: "
<< "\n\tTotal value: " << totalPaid.trackedValueDelta
<< " (initial: " << truncate(initialState.totalValue)
<< ", error: " << truncate(initialState.totalValue - totalPaid.trackedValueDelta)
<< ")\n\tPrincipal: " << totalPaid.trackedPrincipalDelta
<< " (initial: " << truncate(initialState.principalOutstanding) << ", error: "
<< truncate(initialState.principalOutstanding - totalPaid.trackedPrincipalDelta)
<< ")\n\tInterest: " << totalInterestPaid
<< " (initial: " << truncate(initialInterestDue)
<< ", error: " << truncate(initialInterestDue - totalInterestPaid)
<< ")\n\tMgmt fee: " << totalPaid.trackedManagementFeeDelta
<< " (initial: " << truncate(initialState.managementFeeOutstanding) << ", error: "
<< truncate(
initialState.managementFeeOutstanding - totalPaid.trackedManagementFeeDelta)
<< ")\n\tTotal payments made: " << totalPaymentsMade << std::endl;
}
}
void
runLoan(
AssetType assetType,
BrokerParameters const& brokerParams,
LoanParameters const& loanParams)
{
using namespace jtx;
Account const issuer("issuer");
Account const lender("lender");
Account const borrower("borrower");
Env env(*this, all);
auto loanResult =
createLoan(env, assetType, brokerParams, loanParams, issuer, lender, borrower);
if (BEAST_EXPECT(loanResult); !loanResult.has_value())
return;
auto broker = std::get<BrokerInfo>(*loanResult);
auto loanKeylet = std::get<Keylet>(*loanResult);
auto pseudoAcct = std::get<Account>(*loanResult);
VerifyLoanStatus verifyLoanStatus(env, broker, pseudoAcct, loanKeylet);
makeLoanPayments(
env,
broker,
loanParams,
loanKeylet,
verifyLoanStatus,
issuer,
lender,
borrower,
PaymentParameters{.showStepBalances = true});
}
/** Runs through the complete lifecycle of a loan
*
* 1. Create a loan.
* 2. Test a bunch of transaction failure conditions.
* 3. Use the `toEndOfLife` callback to take the loan to 0. How that is done
* depends on the callback. e.g. Default, Early payoff, make all the
* normal payments, etc.
* 4. Delete the loan. The loan will alternate between being deleted by the
* lender and the borrower.
*/
void
lifecycle(
std::string const& caseLabel,
char const* label,
jtx::Env& env,
Number const& loanAmount,
int interestExponent,
jtx::Account const& lender,
jtx::Account const& borrower,
jtx::Account const& evan,
BrokerInfo const& broker,
jtx::Account const& pseudoAcct,
std::uint32_t flags,
// The end of life callback is expected to take the loan to 0 payments
// remaining, one way or another
std::function<void(Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus)>
toEndOfLife)
{
auto const [keylet, loanSequence] = [&]() {
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
{
// will be invalid
return std::make_pair(keylet::loan(broker.brokerID), std::uint32_t(0));
}
// Broker has no loans
BEAST_EXPECT(brokerSle->at(sfOwnerCount) == 0);
// The loan keylet is based on the LoanSequence of the _LOAN_BROKER_
// object.
auto const loanSequence = brokerSle->at(sfLoanSequence);
return std::make_pair(keylet::loan(broker.brokerID, loanSequence), loanSequence);
}();
VerifyLoanStatus const verifyLoanStatus(env, broker, pseudoAcct, keylet);
// No loans yet
verifyLoanStatus.checkBroker(0, 0, TenthBips32{0}, 1, 0, 0);
if (!BEAST_EXPECT(loanSequence != 0))
return;
testcase << caseLabel << " " << label;
using namespace jtx;
using namespace loan;
using namespace std::chrono_literals;
auto applyExponent = [interestExponent, this](TenthBips32 value) mutable {
BEAST_EXPECT(value > TenthBips32(0));
while (interestExponent > 0)
{
auto const oldValue = value;
value *= 10;
--interestExponent;
BEAST_EXPECT(value / 10 == oldValue);
}
while (interestExponent < 0)
{
auto const oldValue = value;
value /= 10;
++interestExponent;
BEAST_EXPECT(value * 10 == oldValue);
}
return value;
};
auto const borrowerOwnerCount = env.ownerCount(borrower);
auto const loanSetFee = env.current()->fees().base * 2;
LoanParameters const loanParams{
.account = borrower,
.counter = lender,
.counterpartyExplicit = false,
.principalRequest = loanAmount,
.setFee = loanSetFee,
.originationFee = 1,
.serviceFee = 2,
.lateFee = 3,
.closeFee = 4,
.overFee = applyExponent(percentageToTenthBips(5) / 10),
.interest = applyExponent(percentageToTenthBips(12)),
// 2.4%
.lateInterest = applyExponent(percentageToTenthBips(24) / 10),
.closeInterest = applyExponent(percentageToTenthBips(36) / 10),
.overpaymentInterest = applyExponent(percentageToTenthBips(48) / 10),
.payTotal = 12,
.payInterval = 600,
.gracePd = 60,
.flags = flags,
};
Number const principalRequestAmount = broker.asset(loanParams.principalRequest).value();
auto const originationFeeAmount = broker.asset(*loanParams.originationFee).value();
auto const serviceFeeAmount = broker.asset(*loanParams.serviceFee).value();
auto const lateFeeAmount = broker.asset(*loanParams.lateFee).value();
auto const closeFeeAmount = broker.asset(*loanParams.closeFee).value();
auto const borrowerStartbalance = env.balance(borrower, broker.asset);
auto createJtx = loanParams(env, broker);
// Successfully create a Loan
env(createJtx);
env.close();
auto const startDate = env.current()->header().parentCloseTime.time_since_epoch().count();
if (auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle))
{
BEAST_EXPECT(brokerSle->at(sfOwnerCount) == 1);
}
{
// Need to account for fees if the loan is in XRP
PrettyAmount adjustment = broker.asset(0);
if (broker.asset.native())
{
adjustment = 2 * env.current()->fees().base;
}
BEAST_EXPECT(
env.balance(borrower, broker.asset).value() ==
borrowerStartbalance.value() + principalRequestAmount - originationFeeAmount -
adjustment.value());
}
auto const loanFlags =
createJtx.stx->isFlag(tfLoanOverpayment) ? lsfLoanOverpayment : LedgerSpecificFlags(0);
if (auto loan = env.le(keylet); BEAST_EXPECT(loan))
{
// log << "loan after create: " << to_string(loan->getJson())
// << std::endl;
BEAST_EXPECT(
loan->isFlag(lsfLoanOverpayment) == createJtx.stx->isFlag(tfLoanOverpayment));
BEAST_EXPECT(loan->at(sfLoanSequence) == loanSequence);
BEAST_EXPECT(loan->at(sfBorrower) == borrower.id());
BEAST_EXPECT(loan->at(sfLoanBrokerID) == broker.brokerID);
BEAST_EXPECT(loan->at(sfLoanOriginationFee) == originationFeeAmount);
BEAST_EXPECT(loan->at(sfLoanServiceFee) == serviceFeeAmount);
BEAST_EXPECT(loan->at(sfLatePaymentFee) == lateFeeAmount);
BEAST_EXPECT(loan->at(sfClosePaymentFee) == closeFeeAmount);
BEAST_EXPECT(loan->at(sfOverpaymentFee) == *loanParams.overFee);
BEAST_EXPECT(loan->at(sfInterestRate) == *loanParams.interest);
BEAST_EXPECT(loan->at(sfLateInterestRate) == *loanParams.lateInterest);
BEAST_EXPECT(loan->at(sfCloseInterestRate) == *loanParams.closeInterest);
BEAST_EXPECT(loan->at(sfOverpaymentInterestRate) == *loanParams.overpaymentInterest);
BEAST_EXPECT(loan->at(sfStartDate) == startDate);
BEAST_EXPECT(loan->at(sfPaymentInterval) == *loanParams.payInterval);
BEAST_EXPECT(loan->at(sfGracePeriod) == *loanParams.gracePd);
BEAST_EXPECT(loan->at(sfPreviousPaymentDueDate) == 0);
BEAST_EXPECT(loan->at(sfNextPaymentDueDate) == startDate + *loanParams.payInterval);
BEAST_EXPECT(loan->at(sfPaymentRemaining) == *loanParams.payTotal);
BEAST_EXPECT(
loan->at(sfLoanScale) >=
(broker.asset.integral()
? 0
: std::max(broker.vaultScale(env), principalRequestAmount.exponent())));
BEAST_EXPECT(loan->at(sfPrincipalOutstanding) == principalRequestAmount);
}
auto state = getCurrentState(env, broker, keylet, verifyLoanStatus);
auto const loanProperties = computeLoanProperties(
broker.asset.raw(),
state.principalOutstanding,
state.interestRate,
state.paymentInterval,
state.paymentRemaining,
broker.params.managementFeeRate,
state.loanScale);
verifyLoanStatus(
0,
startDate + *loanParams.payInterval,
*loanParams.payTotal,
state.loanScale,
loanProperties.loanState.valueOutstanding,
principalRequestAmount,
loanProperties.loanState.managementFeeDue,
loanProperties.periodicPayment,
loanFlags | 0);
// Manage the loan
// no-op
env(manage(lender, keylet.key, 0));
{
// no flags
auto jt = manage(lender, keylet.key, 0);
jt.removeMember(sfFlags.getName());
env(jt);
}
// Only the lender can manage
env(manage(evan, keylet.key, 0), ter(tecNO_PERMISSION));
// unknown flags
env(manage(lender, keylet.key, tfLoanManageMask), ter(temINVALID_FLAG));
// combinations of flags are not allowed
env(manage(lender, keylet.key, tfLoanUnimpair | tfLoanImpair), ter(temINVALID_FLAG));
env(manage(lender, keylet.key, tfLoanImpair | tfLoanDefault), ter(temINVALID_FLAG));
env(manage(lender, keylet.key, tfLoanUnimpair | tfLoanDefault), ter(temINVALID_FLAG));
env(manage(lender, keylet.key, tfLoanUnimpair | tfLoanImpair | tfLoanDefault),
ter(temINVALID_FLAG));
// invalid loan ID
env(manage(lender, broker.brokerID, tfLoanImpair), ter(tecNO_ENTRY));
// Loan is unimpaired, can't unimpair it again
env(manage(lender, keylet.key, tfLoanUnimpair), ter(tecNO_PERMISSION));
// Loan is unimpaired, it can go into default, but only after it's past
// due
env(manage(lender, keylet.key, tfLoanDefault), ter(tecTOO_SOON));
// Check the vault
bool const canImpair = canImpairLoan(env, broker, state);
// Impair the loan, if possible
env(manage(lender, keylet.key, tfLoanImpair),
canImpair ? ter(tesSUCCESS) : ter(tecLIMIT_EXCEEDED));
// Unimpair the loan
env(manage(lender, keylet.key, tfLoanUnimpair),
canImpair ? ter(tesSUCCESS) : ter(tecNO_PERMISSION));
auto const nextDueDate = startDate + *loanParams.payInterval;
env.close();
verifyLoanStatus(
0,
nextDueDate,
*loanParams.payTotal,
loanProperties.loanScale,
loanProperties.loanState.valueOutstanding,
principalRequestAmount,
loanProperties.loanState.managementFeeDue,
loanProperties.periodicPayment,
loanFlags | 0);
// Can't delete the loan yet. It has payments remaining.
env(del(lender, keylet.key), ter(tecHAS_OBLIGATIONS));
if (BEAST_EXPECT(toEndOfLife))
toEndOfLife(keylet, verifyLoanStatus);
env.close();
// Verify the loan is at EOL
if (auto loan = env.le(keylet); BEAST_EXPECT(loan))
{
BEAST_EXPECT(loan->at(sfPaymentRemaining) == 0);
BEAST_EXPECT(loan->at(sfPrincipalOutstanding) == 0);
}
auto const borrowerStartingBalance = env.balance(borrower, broker.asset);
// Try to delete the loan broker with an active loan
env(loanBroker::del(lender, broker.brokerID), ter(tecHAS_OBLIGATIONS));
// Ensure the above tx doesn't get ordered after the LoanDelete and
// delete our broker!
env.close();
// Test failure cases
env(del(lender, keylet.key, tfLoanOverpayment), ter(temINVALID_FLAG));
env(del(evan, keylet.key), ter(tecNO_PERMISSION));
env(del(lender, broker.brokerID), ter(tecNO_ENTRY));
// Delete the loan
// Either the borrower or the lender can delete the loan. Alternate
// between who does it across tests.
static unsigned deleteCounter = 0;
auto const deleter = ((++deleteCounter % 2) != 0u) ? lender : borrower;
env(del(deleter, keylet.key));
env.close();
PrettyAmount adjustment = broker.asset(0);
if (deleter == borrower)
{
// Need to account for fees if the loan is in XRP
if (broker.asset.native())
{
adjustment = env.current()->fees().base;
}
}
// No loans left
verifyLoanStatus.checkBroker(0, 0, *loanParams.interest, 1, 0, 0);
BEAST_EXPECT(
env.balance(borrower, broker.asset).value() ==
borrowerStartingBalance.value() - adjustment);
BEAST_EXPECT(env.ownerCount(borrower) == borrowerOwnerCount);
if (auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle))
{
BEAST_EXPECT(brokerSle->at(sfOwnerCount) == 0);
}
}
static std::string
getCurrencyLabel(Asset const& asset)
{
if (asset.native())
return "XRP";
if (asset.holds<Issue>())
return "IOU";
if (asset.holds<MPTIssue>())
return "MPT";
return "Unknown";
}
/** Wrapper to run a series of lifecycle tests for a given asset and loan
* amount
*
* Will be used in the future to vary the loan parameters. For now, it is
* only called once.
*
* Tests a bunch of LoanSet failure conditions before lifecycle.
*/
template <class TAsset, std::size_t NAsset>
void
testCaseWrapper(
jtx::Env& env,
jtx::MPTTester& mptt,
std::array<TAsset, NAsset> const& assets,
BrokerInfo const& broker,
Number const& loanAmount,
int interestExponent)
{
using namespace jtx;
using namespace Lending;
auto const& asset = broker.asset.raw();
auto const currencyLabel = getCurrencyLabel(asset);
auto const caseLabel = [&]() {
std::stringstream ss;
ss << "Lifecycle: " << loanAmount << " " << currencyLabel
<< " Scale interest to: " << interestExponent << " ";
return ss.str();
}();
testcase << caseLabel;
using namespace loan;
using namespace std::chrono_literals;
using d = NetClock::duration;
using tp = NetClock::time_point;
Account const issuer{"issuer"};
// For simplicity, lender will be the sole actor for the vault &
// brokers.
Account const lender{"lender"};
// Borrower only wants to borrow
Account const borrower{"borrower"};
// Evan will attempt to be naughty
Account const evan{"evan"};
// Do not fund alice
Account const alice{"alice"};
Number const principalRequest = broker.asset(loanAmount).value();
Number const maxCoveredLoanValue = broker.params.maxCoveredLoanValue(0);
BEAST_EXPECT(maxCoveredLoanValue == 1000 * 100 / 10);
Number const maxCoveredLoanRequest = broker.asset(maxCoveredLoanValue).value();
Number const totalVaultRequest = broker.asset(broker.params.vaultDeposit).value();
Number const debtMaximumRequest = broker.asset(broker.params.debtMax).value();
auto const loanSetFee = fee(env.current()->fees().base * 2);
auto const pseudoAcct = [&]() {
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
return Account{lender};
auto const brokerPseudo = brokerSle->at(sfAccount);
return Account("Broker pseudo-account", brokerPseudo);
}();
auto const baseFee = env.current()->fees().base;
auto badKeylet = keylet::vault(lender.id(), env.seq(lender));
// Try some failure cases
// flags are checked first
env(set(evan, broker.brokerID, principalRequest, tfLoanSetMask),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(temINVALID_FLAG));
// field length validation
// sfData: good length, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
data(std::string(maxDataPayloadLength, 'X')),
loanSetFee,
ter(tefBAD_AUTH));
// sfData: too long
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
data(std::string(maxDataPayloadLength + 1, 'Y')),
loanSetFee,
ter(temINVALID));
// field range validation
// sfOverpaymentFee: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
overpaymentFee(maxOverpaymentFee),
loanSetFee,
ter(tefBAD_AUTH));
// sfOverpaymentFee: too big
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
overpaymentFee(maxOverpaymentFee + 1),
loanSetFee,
ter(temINVALID));
// sfInterestRate: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
interestRate(maxInterestRate),
loanSetFee,
ter(tefBAD_AUTH));
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
interestRate(TenthBips32(0)),
loanSetFee,
ter(tefBAD_AUTH));
// sfInterestRate: too big
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
interestRate(maxInterestRate + 1),
loanSetFee,
ter(temINVALID));
// sfInterestRate: too small
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
interestRate(TenthBips32(-1)),
loanSetFee,
ter(temINVALID));
// sfLateInterestRate: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
lateInterestRate(maxLateInterestRate),
loanSetFee,
ter(tefBAD_AUTH));
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
lateInterestRate(TenthBips32(0)),
loanSetFee,
ter(tefBAD_AUTH));
// sfLateInterestRate: too big
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
lateInterestRate(maxLateInterestRate + 1),
loanSetFee,
ter(temINVALID));
// sfLateInterestRate: too small
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
lateInterestRate(TenthBips32(-1)),
loanSetFee,
ter(temINVALID));
// sfCloseInterestRate: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
closeInterestRate(maxCloseInterestRate),
loanSetFee,
ter(tefBAD_AUTH));
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
closeInterestRate(TenthBips32(0)),
loanSetFee,
ter(tefBAD_AUTH));
// sfCloseInterestRate: too big
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
closeInterestRate(maxCloseInterestRate + 1),
loanSetFee,
ter(temINVALID));
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
closeInterestRate(TenthBips32(-1)),
loanSetFee,
ter(temINVALID));
// sfOverpaymentInterestRate: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
overpaymentInterestRate(maxOverpaymentInterestRate),
loanSetFee,
ter(tefBAD_AUTH));
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
overpaymentInterestRate(TenthBips32(0)),
loanSetFee,
ter(tefBAD_AUTH));
// sfOverpaymentInterestRate: too big
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
overpaymentInterestRate(maxOverpaymentInterestRate + 1),
loanSetFee,
ter(temINVALID));
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
overpaymentInterestRate(TenthBips32(-1)),
loanSetFee,
ter(temINVALID));
// sfPaymentTotal: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
paymentTotal(LoanSet::minPaymentTotal),
loanSetFee,
ter(tefBAD_AUTH));
// sfPaymentTotal: too small (there is no max)
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
paymentTotal(LoanSet::minPaymentTotal - 1),
loanSetFee,
ter(temINVALID));
// sfPaymentInterval: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
paymentInterval(LoanSet::minPaymentInterval),
loanSetFee,
ter(tefBAD_AUTH));
// sfPaymentInterval: too small (there is no max)
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
paymentInterval(LoanSet::minPaymentInterval - 1),
loanSetFee,
ter(temINVALID));
// sfGracePeriod: good value, bad account
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, borrower),
paymentInterval(LoanSet::minPaymentInterval * 2),
gracePeriod(LoanSet::minPaymentInterval * 2),
loanSetFee,
ter(tefBAD_AUTH));
// sfGracePeriod: larger than paymentInterval
env(set(evan, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
paymentInterval(LoanSet::minPaymentInterval * 2),
gracePeriod(LoanSet::minPaymentInterval * 3),
loanSetFee,
ter(temINVALID));
// insufficient fee - single sign
env(set(borrower, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
ter(telINSUF_FEE_P));
// insufficient fee - multisign
env(signers(lender, 2, {{evan, 1}, {borrower, 1}}));
env(signers(borrower, 2, {{evan, 1}, {lender, 1}}));
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
msig(evan, lender),
msig(sfCounterpartySignature, evan, borrower),
fee(env.current()->fees().base * 5 - 1),
ter(telINSUF_FEE_P));
// Bad multisign signatures for borrower (Account)
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
msig(alice, issuer),
msig(sfCounterpartySignature, evan, borrower),
fee(env.current()->fees().base * 5),
ter(tefBAD_SIGNATURE));
// Bad multisign signatures for issuer (Counterparty)
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
msig(evan, lender),
msig(sfCounterpartySignature, alice, issuer),
fee(env.current()->fees().base * 5 - 1),
ter(tefBAD_SIGNATURE));
env(signers(lender, none));
env(signers(borrower, none));
// multisign sufficient fee, but no signers set up
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
msig(evan, lender),
msig(sfCounterpartySignature, evan, borrower),
fee(env.current()->fees().base * 5),
ter(tefNOT_MULTI_SIGNING));
// not the broker owner, no counterparty, not signed by broker
// owner
env(set(borrower, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, evan),
loanSetFee,
ter(tefBAD_AUTH));
// not the broker owner, counterparty is borrower
env(set(evan, broker.brokerID, principalRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
loanSetFee,
ter(tecNO_PERMISSION));
// not a LoanBroker object, no counterparty
env(set(lender, badKeylet.key, principalRequest),
sig(sfCounterpartySignature, evan),
loanSetFee,
ter(temBAD_SIGNER));
// not a LoanBroker object, counterparty is valid
env(set(lender, badKeylet.key, principalRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
loanSetFee,
ter(tecNO_ENTRY));
// borrower doesn't exist
env(set(lender, broker.brokerID, principalRequest),
counterparty(alice),
sig(sfCounterpartySignature, alice),
loanSetFee,
ter(terNO_ACCOUNT));
// Request more funds than the vault has available
env(set(evan, broker.brokerID, totalVaultRequest + 1),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(tecINSUFFICIENT_FUNDS));
// Request more funds than the broker's first-loss capital can
// cover.
env(set(evan, broker.brokerID, maxCoveredLoanRequest + 1),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(tecINSUFFICIENT_FUNDS));
// Frozen trust line / locked MPT issuance
// XRP can not be frozen, but run through the loop anyway to test
// the tecLIMIT_EXCEEDED case
{
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
return;
auto const vaultPseudo = [&]() {
auto const vaultSle = env.le(keylet::vault(brokerSle->at(sfVaultID)));
if (!BEAST_EXPECT(vaultSle))
{
// This will be wrong, but the test has failed anyway.
return Account{lender};
}
auto vaultPseudo = Account("Vault pseudo-account", vaultSle->at(sfAccount));
return vaultPseudo;
}();
auto const [freeze, deepfreeze, unfreeze, expectedResult] =
[&]() -> std::tuple<
std::function<void(Account const& holder)>,
std::function<void(Account const& holder)>,
std::function<void(Account const& holder)>,
TER> {
// Freeze / lock the asset
std::function<void(Account const& holder)> empty;
if (broker.asset.native())
{
// XRP can't be frozen
return std::make_tuple(empty, empty, empty, tesSUCCESS);
}
if (broker.asset.holds<Issue>())
{
auto freeze = [&](Account const& holder) {
env(trust(issuer, holder[iouCurrency](0), tfSetFreeze));
};
auto deepfreeze = [&](Account const& holder) {
env(trust(issuer, holder[iouCurrency](0), tfSetFreeze | tfSetDeepFreeze));
};
auto unfreeze = [&](Account const& holder) {
env(trust(
issuer, holder[iouCurrency](0), tfClearFreeze | tfClearDeepFreeze));
};
return std::make_tuple(freeze, deepfreeze, unfreeze, tecFROZEN);
}
auto freeze = [&](Account const& holder) {
mptt.set({.account = issuer, .holder = holder, .flags = tfMPTLock});
};
auto unfreeze = [&](Account const& holder) {
mptt.set({.account = issuer, .holder = holder, .flags = tfMPTUnlock});
};
return std::make_tuple(freeze, empty, unfreeze, tecLOCKED);
}();
// Try freezing the accounts that can't be frozen
if (freeze)
{
for (auto const& account : {vaultPseudo, evan})
{
// Freeze the account
freeze(account);
// Try to create a loan with a frozen line
env(set(evan, broker.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(expectedResult));
// Unfreeze the account
BEAST_EXPECT(unfreeze);
unfreeze(account);
// Ensure the line is unfrozen with a request that is fine
// except too it requests more principal than the broker can
// carry
env(set(evan, broker.brokerID, debtMaximumRequest + 1),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(tecLIMIT_EXCEEDED));
}
}
// Deep freeze the borrower, which prevents them from receiving
// funds
if (deepfreeze)
{
// Make sure evan has a trust line that so the issuer can
// freeze it. (Don't need to do this for the borrower,
// because LoanSet will create a line to the borrower
// automatically.)
env(trust(evan, issuer[iouCurrency](100'000)));
for (auto const& account : {// these accounts can't be frozen, which deep freeze
// implies
vaultPseudo,
evan,
// these accounts can't be deep frozen
lender})
{
// Freeze evan
deepfreeze(account);
// Try to create a loan with a deep frozen line
env(set(evan, broker.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(expectedResult));
// Unfreeze evan
BEAST_EXPECT(unfreeze);
unfreeze(account);
// Ensure the line is unfrozen with a request that is fine
// except too it requests more principal than the broker can
// carry
env(set(evan, broker.brokerID, debtMaximumRequest + 1),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(tecLIMIT_EXCEEDED));
}
}
}
// Finally! Create a loan
auto coverAvailable = [&env, this](uint256 const& brokerID, Number const& expected) {
if (auto const brokerSle = env.le(keylet::loanbroker(brokerID));
BEAST_EXPECT(brokerSle))
{
auto const available = brokerSle->at(sfCoverAvailable);
BEAST_EXPECT(available == expected);
return available;
}
return Number{};
};
auto getDefaultInfo = [&env, this](LoanState const& state, BrokerInfo const& broker) {
if (auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle))
{
BEAST_EXPECT(
state.loanScale >=
(broker.asset.integral()
? 0
: std::max(
broker.vaultScale(env), state.principalOutstanding.exponent())));
NumberRoundModeGuard mg(Number::upward);
auto const defaultAmount = roundToAsset(
broker.asset,
std::min(
tenthBipsOfValue(
tenthBipsOfValue(
brokerSle->at(sfDebtTotal), broker.params.coverRateMin),
broker.params.coverRateLiquidation),
state.totalValue - state.managementFeeOutstanding),
state.loanScale);
return std::make_pair(defaultAmount, brokerSle->at(sfOwner));
}
return std::make_pair(Number{}, AccountID{});
};
auto replenishCover = [&env, &coverAvailable](
BrokerInfo const& broker,
AccountID const& brokerAcct,
Number const& startingCoverAvailable,
Number const& amountToBeCovered) {
coverAvailable(broker.brokerID, startingCoverAvailable - amountToBeCovered);
env(loanBroker::coverDeposit(
brokerAcct, broker.brokerID, STAmount{broker.asset, amountToBeCovered}));
coverAvailable(broker.brokerID, startingCoverAvailable);
env.close();
};
auto defaultImmediately = [&](std::uint32_t baseFlag, bool impair = true) {
return [&, impair, baseFlag](
Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) {
// toEndOfLife
//
// Default the loan
// Initialize values with the current state
auto state = getCurrentState(env, broker, loanKeylet, verifyLoanStatus);
BEAST_EXPECT(state.flags == baseFlag);
auto const& broker = verifyLoanStatus.broker;
auto const startingCoverAvailable = coverAvailable(
broker.brokerID, broker.asset(broker.params.coverDeposit).number());
if (impair)
{
// Check the vault
bool const canImpair = canImpairLoan(env, broker, state);
// Impair the loan, if possible
env(manage(lender, loanKeylet.key, tfLoanImpair),
canImpair ? ter(tesSUCCESS) : ter(tecLIMIT_EXCEEDED));
if (canImpair)
{
state.flags |= tfLoanImpair;
state.nextPaymentDate = env.now().time_since_epoch().count();
// Once the loan is impaired, it can't be impaired again
env(manage(lender, loanKeylet.key, tfLoanImpair), ter(tecNO_PERMISSION));
}
verifyLoanStatus(state);
}
auto const nextDueDate = tp{d{state.nextPaymentDate}};
// Can't default the loan yet. The grace period hasn't
// expired
env(manage(lender, loanKeylet.key, tfLoanDefault), ter(tecTOO_SOON));
// Let some time pass so that the loan can be
// defaulted
env.close(nextDueDate + 60s);
auto const [amountToBeCovered, brokerAcct] = getDefaultInfo(state, broker);
// Default the loan
env(manage(lender, loanKeylet.key, tfLoanDefault));
env.close();
// The LoanBroker just lost some of it's first-loss capital.
// Replenish it.
replenishCover(broker, brokerAcct, startingCoverAvailable, amountToBeCovered);
state.flags |= tfLoanDefault;
state.paymentRemaining = 0;
state.totalValue = 0;
state.principalOutstanding = 0;
state.managementFeeOutstanding = 0;
state.nextPaymentDate = 0;
verifyLoanStatus(state);
// Once a loan is defaulted, it can't be managed
env(manage(lender, loanKeylet.key, tfLoanUnimpair), ter(tecNO_PERMISSION));
env(manage(lender, loanKeylet.key, tfLoanImpair), ter(tecNO_PERMISSION));
// Can't make a payment on it either
env(pay(borrower, loanKeylet.key, broker.asset(300)), ter(tecKILLED));
};
};
auto singlePayment = [&](Keylet const& loanKeylet,
VerifyLoanStatus const& verifyLoanStatus,
LoanState& state,
STAmount const& payoffAmount,
std::uint32_t numPayments,
std::uint32_t baseFlag,
std::uint32_t txFlags) {
// toEndOfLife
//
verifyLoanStatus(state);
// Send some bogus pay transactions
env(pay(borrower, keylet::loan(uint256(0)).key, broker.asset(10), txFlags),
ter(temINVALID));
// broker.asset(80) is less than a single payment, but all these
// checks fail before that matters
env(pay(borrower, loanKeylet.key, broker.asset(-80), txFlags), ter(temBAD_AMOUNT));
env(pay(borrower, broker.brokerID, broker.asset(80), txFlags), ter(tecNO_ENTRY));
env(pay(evan, loanKeylet.key, broker.asset(80), txFlags), ter(tecNO_PERMISSION));
// TODO: Write a general "isFlag" function? See STObject::isFlag.
// Maybe add a static overloaded member?
if (!(state.flags & lsfLoanOverpayment))
{
// If the loan does not allow overpayments, send a payment that
// tries to make an overpayment. Do not include `txFlags`, so we
// don't end up duplicating the next test transaction.
env(pay(borrower,
loanKeylet.key,
STAmount{broker.asset, state.periodicPayment * Number{15, -1}},
tfLoanOverpayment),
fee(XRPAmount{baseFee * (Number{15, -1} / loanPaymentsPerFeeIncrement + 1)}),
ter(temINVALID_FLAG));
}
// Try to send a payment marked as multiple mutually exclusive
// payment types. Do not include `txFlags`, so we don't duplicate
// the prior test transaction.
env(pay(borrower,
loanKeylet.key,
broker.asset(state.periodicPayment * 2),
tfLoanLatePayment | tfLoanFullPayment),
ter(temINVALID_FLAG));
env(pay(borrower,
loanKeylet.key,
broker.asset(state.periodicPayment * 2),
tfLoanLatePayment | tfLoanOverpayment),
ter(temINVALID_FLAG));
env(pay(borrower,
loanKeylet.key,
broker.asset(state.periodicPayment * 2),
tfLoanOverpayment | tfLoanFullPayment),
ter(temINVALID_FLAG));
env(pay(borrower,
loanKeylet.key,
broker.asset(state.periodicPayment * 2),
tfLoanLatePayment | tfLoanOverpayment | tfLoanFullPayment),
ter(temINVALID_FLAG));
{
auto const otherAsset =
broker.asset.raw() == assets[0].raw() ? assets[1] : assets[0];
env(pay(borrower, loanKeylet.key, otherAsset(100), txFlags), ter(tecWRONG_ASSET));
}
// Amount doesn't cover a single payment
env(pay(borrower, loanKeylet.key, STAmount{broker.asset, 1}, txFlags),
ter(tecINSUFFICIENT_PAYMENT));
// Get the balance after these failed transactions take
// fees
auto const borrowerBalanceBeforePayment = env.balance(borrower, broker.asset);
BEAST_EXPECT(payoffAmount > state.principalOutstanding);
// Try to pay a little extra to show that it's _not_
// taken
auto const transactionAmount = payoffAmount + broker.asset(10);
// Send a transaction that tries to pay more than the borrowers's
// balance
XRPAmount const badFee{
baseFee *
(borrowerBalanceBeforePayment.number() * 2 / state.periodicPayment /
loanPaymentsPerFeeIncrement +
1)};
env(pay(borrower,
loanKeylet.key,
STAmount{broker.asset, borrowerBalanceBeforePayment.number() * 2},
txFlags),
fee(badFee),
ter(tecINSUFFICIENT_FUNDS));
XRPAmount const goodFee{baseFee * (numPayments / loanPaymentsPerFeeIncrement + 1)};
env(pay(borrower, loanKeylet.key, transactionAmount, txFlags), fee(goodFee));
env.close();
// log << env.meta()->getJson() << std::endl;
// Need to account for fees if the loan is in XRP
PrettyAmount adjustment = broker.asset(0);
if (broker.asset.native())
{
adjustment = badFee + goodFee;
}
state.paymentRemaining = 0;
state.principalOutstanding = 0;
state.totalValue = 0;
state.managementFeeOutstanding = 0;
state.previousPaymentDate =
state.nextPaymentDate + (state.paymentInterval * (numPayments - 1));
state.nextPaymentDate = 0;
verifyLoanStatus(state);
verifyLoanStatus.checkPayment(
state.loanScale, borrower, borrowerBalanceBeforePayment, payoffAmount, adjustment);
// Can't impair or default a paid off loan
env(manage(lender, loanKeylet.key, tfLoanImpair), ter(tecNO_PERMISSION));
env(manage(lender, loanKeylet.key, tfLoanDefault), ter(tecNO_PERMISSION));
};
auto fullPayment = [&](std::uint32_t baseFlag) {
return [&, baseFlag](
Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) {
// toEndOfLife
//
auto state = getCurrentState(env, broker, loanKeylet, verifyLoanStatus);
env.close(state.startDate + 20s);
auto const loanAge = (env.now() - state.startDate).count();
BEAST_EXPECT(loanAge == 30);
// Full payoff amount will consist of
// 1. principal outstanding (1000)
// 2. accrued interest (at 12%)
// 3. prepayment penalty (closeInterest at 3.6%)
// 4. close payment fee (4)
// Calculate these values without the helper functions
// to verify they're working correctly The numbers in
// the below BEAST_EXPECTs may not hold across assets.
Number const interval = state.paymentInterval;
auto const periodicRate = interval * Number(12, -2) / secondsInYear;
BEAST_EXPECT(
periodicRate == Number(2283105022831050228ULL, -24, Number::normalized{}));
STAmount const principalOutstanding{broker.asset, state.principalOutstanding};
STAmount const accruedInterest{
broker.asset, state.principalOutstanding * periodicRate * loanAge / interval};
BEAST_EXPECT(accruedInterest == broker.asset(Number(1141552511415525, -19)));
STAmount const prepaymentPenalty{
broker.asset, state.principalOutstanding * Number(36, -3)};
BEAST_EXPECT(prepaymentPenalty == broker.asset(36));
STAmount const closePaymentFee = broker.asset(4);
auto const payoffAmount = roundToScale(
principalOutstanding + accruedInterest + prepaymentPenalty + closePaymentFee,
state.loanScale);
BEAST_EXPECT(
payoffAmount ==
roundToAsset(
broker.asset,
broker.asset(Number(1040000114155251, -12)).number(),
state.loanScale));
// The terms of this loan actually make the early payoff
// more expensive than just making payments
BEAST_EXPECT(
payoffAmount >
state.paymentRemaining * (state.periodicPayment + broker.asset(2).value()));
singlePayment(
loanKeylet,
verifyLoanStatus,
state,
payoffAmount,
1,
baseFlag,
tfLoanFullPayment);
};
};
auto combineAllPayments = [&](std::uint32_t baseFlag) {
return
[&, baseFlag](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) {
// toEndOfLife
//
auto state = getCurrentState(env, broker, loanKeylet, verifyLoanStatus);
env.close();
BEAST_EXPECT(
STAmount(broker.asset, state.periodicPayment) ==
broker.asset(Number(8333457002039338267, -17)));
// Make all the payments in one transaction
// service fee is 2
auto const startingPayments = state.paymentRemaining;
STAmount const payoffAmount = [&]() {
NumberRoundModeGuard mg(Number::upward);
auto const rawPayoff =
startingPayments * (state.periodicPayment + broker.asset(2).value());
STAmount payoffAmount{broker.asset, rawPayoff};
BEAST_EXPECTS(
payoffAmount == broker.asset(Number(1024014840244721, -12)),
to_string(payoffAmount));
BEAST_EXPECT(payoffAmount > state.principalOutstanding);
payoffAmount = roundToScale(payoffAmount, state.loanScale);
return payoffAmount;
}();
auto const totalPayoffValue =
state.totalValue + startingPayments * broker.asset(2).value();
STAmount const totalPayoffAmount{broker.asset, totalPayoffValue};
BEAST_EXPECTS(
totalPayoffAmount == payoffAmount,
"Payoff amount: " + to_string(payoffAmount) +
". Total Value: " + to_string(totalPayoffAmount));
singlePayment(
loanKeylet,
verifyLoanStatus,
state,
payoffAmount,
state.paymentRemaining,
baseFlag,
0);
};
};
// There are a lot of fields that can be set on a loan, but most
// of them only affect the "math" when a payment is made. The
// only one that really affects behavior is the
// `tfLoanOverpayment` flag.
lifecycle(
caseLabel,
"Loan overpayment allowed - Impair and Default",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
defaultImmediately(lsfLoanOverpayment));
lifecycle(
caseLabel,
"Loan overpayment prohibited - Impair and Default",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
0,
defaultImmediately(0));
lifecycle(
caseLabel,
"Loan overpayment allowed - Default without Impair",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
defaultImmediately(lsfLoanOverpayment, false));
lifecycle(
caseLabel,
"Loan overpayment prohibited - Default without Impair",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
0,
defaultImmediately(0, false));
lifecycle(
caseLabel,
"Loan overpayment prohibited - Pay off immediately",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
0,
fullPayment(0));
lifecycle(
caseLabel,
"Loan overpayment allowed - Pay off immediately",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
fullPayment(lsfLoanOverpayment));
lifecycle(
caseLabel,
"Loan overpayment prohibited - Combine all payments",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
0,
combineAllPayments(0));
lifecycle(
caseLabel,
"Loan overpayment allowed - Combine all payments",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
combineAllPayments(lsfLoanOverpayment));
lifecycle(
caseLabel,
"Loan overpayment prohibited - Make payments",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
0,
[&](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) {
// toEndOfLife
//
// Draw and make multiple payments
auto state = getCurrentState(env, broker, loanKeylet, verifyLoanStatus);
BEAST_EXPECT(state.flags == 0);
env.close();
verifyLoanStatus(state);
env.close(state.startDate + 20s);
auto const loanAge = (env.now() - state.startDate).count();
BEAST_EXPECT(loanAge == 30);
// Periodic payment amount will consist of
// 1. principal outstanding (1000)
// 2. interest interest rate (at 12%)
// 3. payment interval (600s)
// 4. loan service fee (2)
// Calculate these values without the helper functions
// to verify they're working correctly The numbers in
// the below BEAST_EXPECTs may not hold across assets.
Number const interval = state.paymentInterval;
auto const periodicRate = interval * Number(12, -2) / secondsInYear;
BEAST_EXPECT(
periodicRate == Number(2283105022831050228, -24, Number::normalized{}));
STAmount const roundedPeriodicPayment{
broker.asset,
roundPeriodicPayment(broker.asset, state.periodicPayment, state.loanScale)};
testcase << currencyLabel << " Payment components: "
<< "Payments remaining, rawInterest, rawPrincipal, "
"rawMFee, trackedValueDelta, trackedPrincipalDelta, "
"trackedInterestDelta, trackedMgmtFeeDelta, special";
auto const serviceFee = broker.asset(2);
BEAST_EXPECT(
roundedPeriodicPayment ==
roundToScale(
broker.asset(Number(8333457002039338267, -17), Number::upward),
state.loanScale,
Number::upward));
// 83334570.01162141
// Include the service fee
STAmount const totalDue = roundToScale(
roundedPeriodicPayment + serviceFee, state.loanScale, Number::upward);
// Only check the first payment since the rounding
// may drift as payments are made
BEAST_EXPECT(
totalDue ==
roundToScale(
broker.asset(Number(8533457002039338267, -17), Number::upward),
state.loanScale,
Number::upward));
{
auto const raw = computeTheoreticalLoanState(
state.periodicPayment,
periodicRate,
state.paymentRemaining,
broker.params.managementFeeRate);
auto const rounded = constructLoanState(
state.totalValue,
state.principalOutstanding,
state.managementFeeOutstanding);
testcase << currencyLabel << " Loan starting state: " << state.paymentRemaining
<< ", " << raw.interestDue << ", " << raw.principalOutstanding << ", "
<< raw.managementFeeDue << ", " << rounded.valueOutstanding << ", "
<< rounded.principalOutstanding << ", " << rounded.interestDue << ", "
<< rounded.managementFeeDue;
}
// Try to pay a little extra to show that it's _not_
// taken
STAmount const transactionAmount =
STAmount{broker.asset, totalDue} + broker.asset(10);
// Only check the first payment since the rounding
// may drift as payments are made
BEAST_EXPECT(
transactionAmount ==
roundToScale(
broker.asset(Number(9533457002039400, -14), Number::upward),
state.loanScale,
Number::upward));
auto const initialState = state;
detail::PaymentComponents totalPaid{
.trackedValueDelta = 0,
.trackedPrincipalDelta = 0,
.trackedManagementFeeDelta = 0};
Number totalInterestPaid = 0;
std::size_t totalPaymentsMade = 0;
xrpl::LoanState currentTrueState = computeTheoreticalLoanState(
state.periodicPayment,
periodicRate,
state.paymentRemaining,
broker.params.managementFeeRate);
while (state.paymentRemaining > 0)
{
// Compute the expected principal amount
auto const paymentComponents = detail::computePaymentComponents(
broker.asset.raw(),
state.loanScale,
state.totalValue,
state.principalOutstanding,
state.managementFeeOutstanding,
state.periodicPayment,
periodicRate,
state.paymentRemaining,
broker.params.managementFeeRate);
BEAST_EXPECTS(
paymentComponents.specialCase == detail::PaymentSpecialCase::final ||
paymentComponents.trackedValueDelta <= roundedPeriodicPayment,
"Delta: " + to_string(paymentComponents.trackedValueDelta) +
", periodic payment: " + to_string(roundedPeriodicPayment));
xrpl::LoanState const nextTrueState = computeTheoreticalLoanState(
state.periodicPayment,
periodicRate,
state.paymentRemaining - 1,
broker.params.managementFeeRate);
detail::LoanStateDeltas const deltas = currentTrueState - nextTrueState;
testcase << currencyLabel << " Payment components: " << state.paymentRemaining
<< ", " << deltas.interest << ", " << deltas.principal << ", "
<< deltas.managementFee << ", " << paymentComponents.trackedValueDelta
<< ", " << paymentComponents.trackedPrincipalDelta << ", "
<< paymentComponents.trackedInterestPart() << ", "
<< paymentComponents.trackedManagementFeeDelta << ", "
<< [&]() -> char const* {
if (paymentComponents.specialCase == detail::PaymentSpecialCase::final)
return "final";
if (paymentComponents.specialCase == detail::PaymentSpecialCase::extra)
return "extra";
return "none";
}();
auto const totalDueAmount = STAmount{
broker.asset, paymentComponents.trackedValueDelta + serviceFee.number()};
// Due to the rounding algorithms to keep the interest and
// principal in sync with "true" values, the computed amount
// may be a little less than the rounded fixed payment
// amount. For integral types, the difference should be < 3
// (1 unit for each of the interest and management fee). For
// IOUs, the difference should be after the 8th digit.
Number const diff = totalDue - totalDueAmount;
BEAST_EXPECT(
paymentComponents.specialCase == detail::PaymentSpecialCase::final ||
diff == beast::zero ||
(diff > beast::zero &&
((broker.asset.integral() && (static_cast<Number>(diff) < 3)) ||
(state.loanScale - diff.exponent() > 13))));
BEAST_EXPECT(
paymentComponents.trackedValueDelta ==
paymentComponents.trackedPrincipalDelta +
paymentComponents.trackedInterestPart() +
paymentComponents.trackedManagementFeeDelta);
BEAST_EXPECT(
paymentComponents.specialCase == detail::PaymentSpecialCase::final ||
paymentComponents.trackedValueDelta <= roundedPeriodicPayment);
BEAST_EXPECT(
state.paymentRemaining < 12 ||
roundToAsset(
broker.asset, deltas.principal, state.loanScale, Number::upward) ==
roundToScale(
broker.asset(Number(8333228691531218890, -17), Number::upward),
state.loanScale,
Number::upward));
BEAST_EXPECT(
paymentComponents.trackedPrincipalDelta >= beast::zero &&
paymentComponents.trackedPrincipalDelta <= state.principalOutstanding);
BEAST_EXPECT(
paymentComponents.specialCase != detail::PaymentSpecialCase::final ||
paymentComponents.trackedPrincipalDelta == state.principalOutstanding);
BEAST_EXPECT(
paymentComponents.specialCase == detail::PaymentSpecialCase::final ||
(state.periodicPayment.exponent() -
(deltas.principal + deltas.interest + deltas.managementFee -
state.periodicPayment)
.exponent()) > 14);
auto const borrowerBalanceBeforePayment = env.balance(borrower, broker.asset);
if (canImpairLoan(env, broker, state))
{
// Making a payment will unimpair the loan
env(manage(lender, loanKeylet.key, tfLoanImpair));
}
env.close();
// Make the payment
env(pay(borrower, loanKeylet.key, transactionAmount));
env.close();
// Need to account for fees if the loan is in XRP
PrettyAmount adjustment = broker.asset(0);
if (broker.asset.native())
{
adjustment = env.current()->fees().base;
}
// Check the result
verifyLoanStatus.checkPayment(
state.loanScale,
borrower,
borrowerBalanceBeforePayment,
totalDueAmount,
adjustment);
--state.paymentRemaining;
state.previousPaymentDate = state.nextPaymentDate;
if (paymentComponents.specialCase == detail::PaymentSpecialCase::final)
{
state.paymentRemaining = 0;
state.nextPaymentDate = 0;
}
else
{
state.nextPaymentDate += state.paymentInterval;
}
state.principalOutstanding -= paymentComponents.trackedPrincipalDelta;
state.managementFeeOutstanding -= paymentComponents.trackedManagementFeeDelta;
state.totalValue -= paymentComponents.trackedValueDelta;
verifyLoanStatus(state);
totalPaid.trackedValueDelta += paymentComponents.trackedValueDelta;
totalPaid.trackedPrincipalDelta += paymentComponents.trackedPrincipalDelta;
totalPaid.trackedManagementFeeDelta +=
paymentComponents.trackedManagementFeeDelta;
totalInterestPaid += paymentComponents.trackedInterestPart();
++totalPaymentsMade;
currentTrueState = nextTrueState;
}
// Loan is paid off
BEAST_EXPECT(state.paymentRemaining == 0);
BEAST_EXPECT(state.principalOutstanding == 0);
// Make sure all the payments add up
BEAST_EXPECT(totalPaid.trackedValueDelta == initialState.totalValue);
BEAST_EXPECT(totalPaid.trackedPrincipalDelta == initialState.principalOutstanding);
BEAST_EXPECT(
totalPaid.trackedManagementFeeDelta == initialState.managementFeeOutstanding);
// This is almost a tautology given the previous checks, but
// check it anyway for completeness.
BEAST_EXPECT(
totalInterestPaid ==
initialState.totalValue -
(initialState.principalOutstanding +
initialState.managementFeeOutstanding));
BEAST_EXPECT(totalPaymentsMade == initialState.paymentRemaining);
// Can't impair or default a paid off loan
env(manage(lender, loanKeylet.key, tfLoanImpair), ter(tecNO_PERMISSION));
env(manage(lender, loanKeylet.key, tfLoanDefault), ter(tecNO_PERMISSION));
});
#if LOAN_TODO
// TODO
/*
LoanPay fails with tecINVARIANT_FAILED error when loan_broker(also
borrower) tries to do the payment. Here's the scenario: Create a XRP
loan with loan broker as borrower, loan origination fee and loan service
fee. Loan broker makes the first payment with periodic payment and loan
service fee.
*/
auto time = [&](std::string label, std::function<void()> timed) {
if (!BEAST_EXPECT(timed))
return;
using clock_type = std::chrono::steady_clock;
using duration_type = std::chrono::milliseconds;
auto const start = clock_type::now();
timed();
auto const duration =
std::chrono::duration_cast<duration_type>(clock_type::now() - start);
log << label << " took " << duration.count() << "ms" << std::endl;
return duration;
};
lifecycle(
caseLabel,
"timing",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
[&](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) {
// Estimate optimal values for loanPaymentsPerFeeIncrement and
// loanMaximumPaymentsPerTransaction.
using namespace loan;
auto const state = getCurrentState(env, broker, verifyLoanStatus.keylet);
auto const serviceFee = broker.asset(2).value();
STAmount const totalDue{
broker.asset,
roundPeriodicPayment(
broker.asset, state.periodicPayment + serviceFee, state.loanScale)};
// Make a single payment
time("single payment", [&]() { env(pay(borrower, loanKeylet.key, totalDue)); });
env.close();
// Make all but the final payment
auto const numPayments = (state.paymentRemaining - 2);
STAmount const bigPayment{broker.asset, totalDue * numPayments};
XRPAmount const bigFee{baseFee * (numPayments / loanPaymentsPerFeeIncrement + 1)};
time("ten payments", [&]() {
env(pay(borrower, loanKeylet.key, bigPayment), fee(bigFee));
});
env.close();
time("final payment", [&]() {
// Make the final payment
env(pay(borrower, loanKeylet.key, totalDue + STAmount{broker.asset, 1}));
});
env.close();
});
lifecycle(
caseLabel,
"Loan overpayment allowed - Explicit overpayment",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
[&](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) { throw 0; });
lifecycle(
caseLabel,
"Loan overpayment prohibited - Late payment",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
[&](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) { throw 0; });
lifecycle(
caseLabel,
"Loan overpayment allowed - Late payment",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
[&](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) { throw 0; });
lifecycle(
caseLabel,
"Loan overpayment allowed - Late payment and overpayment",
env,
loanAmount,
interestExponent,
lender,
borrower,
evan,
broker,
pseudoAcct,
tfLoanOverpayment,
[&](Keylet const& loanKeylet, VerifyLoanStatus const& verifyLoanStatus) { throw 0; });
#endif
}
void
testLoanSet()
{
using namespace jtx;
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
struct CaseArgs
{
bool requireAuth = false;
bool authorizeBorrower = false;
int initialXRP = 1'000'000;
};
auto const testCase = [&, this](
std::function<void(Env&, BrokerInfo const&, MPTTester&)> mptTest,
std::function<void(Env&, BrokerInfo const&)> iouTest,
CaseArgs args = {}) {
Env env(*this, all);
env.fund(XRP(args.initialXRP), issuer, lender, borrower);
env.close();
if (args.requireAuth)
{
env(fset(issuer, asfRequireAuth));
env.close();
}
// We need two different asset types, MPT and IOU. Prepare MPT
// first
MPTTester mptt{env, issuer, mptInitNoFund};
auto const none = LedgerSpecificFlags(0);
mptt.create(
{.flags = tfMPTCanTransfer | tfMPTCanLock |
(args.requireAuth ? tfMPTRequireAuth : none)});
env.close();
PrettyAsset mptAsset = mptt.issuanceID();
mptt.authorize({.account = lender});
mptt.authorize({.account = borrower});
env.close();
if (args.requireAuth)
{
mptt.authorize({.account = issuer, .holder = lender});
if (args.authorizeBorrower)
mptt.authorize({.account = issuer, .holder = borrower});
env.close();
}
env(pay(issuer, lender, mptAsset(10'000'000)));
env.close();
// Prepare IOU
PrettyAsset const iouAsset = issuer[iouCurrency];
env(trust(lender, iouAsset(10'000'000)));
env(trust(borrower, iouAsset(10'000'000)));
env.close();
if (args.requireAuth)
{
env(trust(issuer, iouAsset(0), lender, tfSetfAuth));
env(pay(issuer, lender, iouAsset(10'000'000)));
if (args.authorizeBorrower)
{
env(trust(issuer, iouAsset(0), borrower, tfSetfAuth));
env(pay(issuer, borrower, iouAsset(10'000)));
}
}
else
{
env(pay(issuer, lender, iouAsset(10'000'000)));
env(pay(issuer, borrower, iouAsset(10'000)));
}
env.close();
// Create vaults and loan brokers
std::array const assets{mptAsset, iouAsset};
std::vector<BrokerInfo> brokers;
brokers.reserve(assets.size());
for (auto const& asset : assets)
{
brokers.emplace_back(createVaultAndBroker(env, asset, lender));
}
if (mptTest)
(mptTest)(env, brokers[0], mptt);
if (iouTest)
(iouTest)(env, brokers[1]);
};
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("MPT issuer is borrower, issuer submits");
env(set(issuer, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
testcase("MPT issuer is borrower, lender submits");
env(set(lender, broker.brokerID, principalRequest),
counterparty(issuer),
sig(sfCounterpartySignature, issuer),
fee(env.current()->fees().base * 5));
},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("IOU issuer is borrower, issuer submits");
env(set(issuer, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
testcase("IOU issuer is borrower, lender submits");
env(set(lender, broker.brokerID, principalRequest),
counterparty(issuer),
sig(sfCounterpartySignature, issuer),
fee(env.current()->fees().base * 5));
},
CaseArgs{.requireAuth = true});
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("MPT unauthorized borrower, borrower submits");
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecNO_AUTH});
testcase("MPT unauthorized borrower, lender submits");
env(set(lender, broker.brokerID, principalRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
fee(env.current()->fees().base * 5),
ter{tecNO_AUTH});
},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("IOU unauthorized borrower, borrower submits");
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecNO_AUTH});
testcase("IOU unauthorized borrower, lender submits");
env(set(lender, broker.brokerID, principalRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
fee(env.current()->fees().base * 5),
ter{tecNO_AUTH});
},
CaseArgs{.requireAuth = true});
auto const [acctReserve, incReserve] = [this]() -> std::pair<int, int> {
Env env{*this, testable_amendments()};
return {
env.current()->fees().accountReserve(0).drops() / DROPS_PER_XRP.drops(),
env.current()->fees().increment.drops() / DROPS_PER_XRP.drops()};
}();
testCase(
[&, this](Env& env, BrokerInfo const& broker, MPTTester& mptt) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase(
"MPT authorized borrower, borrower submits, borrower has "
"no reserve");
mptt.authorize({.account = borrower, .flags = tfMPTUnauthorize});
env.close();
auto const mptoken = keylet::mptoken(mptt.issuanceID(), borrower);
auto const sleMPT1 = env.le(mptoken);
BEAST_EXPECT(sleMPT1 == nullptr);
// Burn some XRP
env(noop(borrower), fee(XRP((acctReserve * 2) + (incReserve * 2))));
env.close();
// Cannot create loan, not enough reserve to create MPToken
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecINSUFFICIENT_RESERVE});
env.close();
// Can create loan now, will implicitly create MPToken
env(pay(issuer, borrower, XRP(incReserve)));
env.close();
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
env.close();
auto const sleMPT2 = env.le(mptoken);
BEAST_EXPECT(sleMPT2 != nullptr);
},
{},
CaseArgs{.initialXRP = (acctReserve * 2) + (incReserve * 8) + 1});
testCase(
{},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase(
"IOU authorized borrower, borrower submits, borrower has "
"no reserve");
// Remove trust line from borrower to issuer
env.trust(broker.asset(0), borrower);
env.close();
env(pay(borrower, issuer, broker.asset(10'000)));
env.close();
auto const trustline = keylet::line(borrower, broker.asset.raw().get<Issue>());
auto const sleLine1 = env.le(trustline);
BEAST_EXPECT(sleLine1 == nullptr);
// Burn some XRP
env(noop(borrower), fee(XRP((acctReserve * 2) + (incReserve * 2))));
env.close();
// Cannot create loan, not enough reserve to create trust line
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecNO_LINE_INSUF_RESERVE});
env.close();
// Can create loan now, will implicitly create trust line
env(pay(issuer, borrower, XRP(incReserve)));
env.close();
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
env.close();
auto const sleLine2 = env.le(trustline);
BEAST_EXPECT(sleLine2 != nullptr);
},
CaseArgs{.initialXRP = (acctReserve * 2) + (incReserve * 8) + 1});
testCase(
[&, this](Env& env, BrokerInfo const& broker, MPTTester& mptt) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase(
"MPT authorized borrower, borrower submits, lender has "
"no reserve");
auto const mptoken = keylet::mptoken(mptt.issuanceID(), lender);
auto const sleMPT1 = env.le(mptoken);
BEAST_EXPECT(sleMPT1 != nullptr);
env(pay(lender, issuer, broker.asset(sleMPT1->at(sfMPTAmount))));
env.close();
mptt.authorize({.account = lender, .flags = tfMPTUnauthorize});
env.close();
auto const sleMPT2 = env.le(mptoken);
BEAST_EXPECT(sleMPT2 == nullptr);
// Burn some XRP
env(noop(lender), fee(XRP(incReserve)));
env.close();
// Cannot create loan, not enough reserve to create MPToken
env(set(borrower, broker.brokerID, principalRequest),
loanOriginationFee(broker.asset(1).value()),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecINSUFFICIENT_RESERVE});
env.close();
// Can create loan now, will implicitly create MPToken
env(pay(issuer, lender, XRP(incReserve)));
env.close();
env(set(borrower, broker.brokerID, principalRequest),
loanOriginationFee(broker.asset(1).value()),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
env.close();
auto const sleMPT3 = env.le(mptoken);
BEAST_EXPECT(sleMPT3 != nullptr);
},
{},
CaseArgs{.initialXRP = (acctReserve * 2) + (incReserve * 8) + 1});
testCase(
{},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase(
"IOU authorized borrower, borrower submits, lender has no "
"reserve");
// Remove trust line from lender to issuer
env.trust(broker.asset(0), lender);
env.close();
auto const trustline = keylet::line(lender, broker.asset.raw().get<Issue>());
auto const sleLine1 = env.le(trustline);
BEAST_EXPECT(sleLine1 != nullptr);
env(pay(lender, issuer, broker.asset(abs(sleLine1->at(sfBalance).value()))));
env.close();
auto const sleLine2 = env.le(trustline);
BEAST_EXPECT(sleLine2 == nullptr);
// Burn some XRP
env(noop(lender), fee(XRP(incReserve)));
env.close();
// Cannot create loan, not enough reserve to create trust line
env(set(borrower, broker.brokerID, principalRequest),
loanOriginationFee(broker.asset(1).value()),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecNO_LINE_INSUF_RESERVE});
env.close();
// Can create loan now, will implicitly create trust line
env(pay(issuer, lender, XRP(incReserve)));
env.close();
env(set(borrower, broker.brokerID, principalRequest),
loanOriginationFee(broker.asset(1).value()),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
env.close();
auto const sleLine3 = env.le(trustline);
BEAST_EXPECT(sleLine3 != nullptr);
},
CaseArgs{.initialXRP = (acctReserve * 2) + (incReserve * 8) + 1});
testCase(
[&, this](Env& env, BrokerInfo const& broker, MPTTester& mptt) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("MPT authorized borrower, unauthorized lender");
auto const mptoken = keylet::mptoken(mptt.issuanceID(), lender);
auto const sleMPT1 = env.le(mptoken);
BEAST_EXPECT(sleMPT1 != nullptr);
env(pay(lender, issuer, broker.asset(sleMPT1->at(sfMPTAmount))));
env.close();
mptt.authorize({.account = lender, .flags = tfMPTUnauthorize});
env.close();
auto const sleMPT2 = env.le(mptoken);
BEAST_EXPECT(sleMPT2 == nullptr);
// Cannot create loan, lender not authorized to receive fee
env(set(borrower, broker.brokerID, principalRequest),
loanOriginationFee(broker.asset(1).value()),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecNO_AUTH});
env.close();
// Cannot create loan, even without an origination fee
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter{tecNO_AUTH});
env.close();
// No MPToken for lender - no authorization and no payment
auto const sleMPT3 = env.le(mptoken);
BEAST_EXPECT(sleMPT3 == nullptr);
},
{},
CaseArgs{.requireAuth = true, .authorizeBorrower = true});
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("MPT authorized borrower, borrower submits");
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("IOU authorized borrower, borrower submits");
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5));
},
CaseArgs{.requireAuth = true, .authorizeBorrower = true});
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("MPT authorized borrower, lender submits");
env(set(lender, broker.brokerID, principalRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
fee(env.current()->fees().base * 5));
},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
testcase("IOU authorized borrower, lender submits");
env(set(lender, broker.brokerID, principalRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
fee(env.current()->fees().base * 5));
},
CaseArgs{.requireAuth = true, .authorizeBorrower = true});
jtx::Account const alice{"alice"};
jtx::Account const bella{"bella"};
auto const msigSetup = [&](Env& env, Account const& account) {
Json::Value tx1 = signers(account, 2, {{alice, 1}, {bella, 1}});
env(tx1);
env.close();
};
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
msigSetup(env, lender);
Number const principalRequest = broker.asset(1'000).value();
testcase(
"MPT authorized borrower, borrower submits, lender "
"multisign");
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
msig(sfCounterpartySignature, alice, bella),
fee(env.current()->fees().base * 5));
},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
msigSetup(env, lender);
Number const principalRequest = broker.asset(1'000).value();
testcase(
"IOU authorized borrower, borrower submits, lender "
"multisign");
env(set(borrower, broker.brokerID, principalRequest),
counterparty(lender),
msig(sfCounterpartySignature, alice, bella),
fee(env.current()->fees().base * 5));
},
CaseArgs{.requireAuth = true, .authorizeBorrower = true});
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
msigSetup(env, borrower);
Number const principalRequest = broker.asset(1'000).value();
testcase(
"MPT authorized borrower, lender submits, borrower "
"multisign");
env(set(lender, broker.brokerID, principalRequest),
counterparty(borrower),
msig(sfCounterpartySignature, alice, bella),
fee(env.current()->fees().base * 5));
},
[&, this](Env& env, BrokerInfo const& broker) {
using namespace loan;
msigSetup(env, borrower);
Number const principalRequest = broker.asset(1'000).value();
testcase(
"IOU authorized borrower, lender submits, borrower "
"multisign");
env(set(lender, broker.brokerID, principalRequest),
counterparty(borrower),
msig(sfCounterpartySignature, alice, bella),
fee(env.current()->fees().base * 5));
},
CaseArgs{.requireAuth = true, .authorizeBorrower = true});
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
Vault vault{env};
auto tx = vault.set({.owner = lender, .id = broker.vaultID});
tx[sfAssetsMaximum] = BrokerParameters::defaults().vaultDeposit;
env(tx);
env.close();
testcase("Vault at maximum value");
env(set(issuer, broker.brokerID, principalRequest),
counterparty(lender),
interestRate(TenthBips32(10'000)),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
ter(tecLIMIT_EXCEEDED));
},
nullptr);
testCase(
[&, this](Env& env, BrokerInfo const& broker, auto&) {
using namespace loan;
Number const principalRequest = broker.asset(1'000).value();
Vault vault{env};
auto tx = vault.set({.owner = lender, .id = broker.vaultID});
tx[sfAssetsMaximum] =
BrokerParameters::defaults().vaultDeposit + broker.asset(1).number();
env(tx);
env.close();
testcase("Vault maximum value exceeded");
env(set(issuer, broker.brokerID, principalRequest),
counterparty(lender),
interestRate(TenthBips32(100'000)),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 5),
paymentTotal(2),
paymentInterval(3600 * 24),
ter(tecLIMIT_EXCEEDED));
},
nullptr);
}
void
testLifecycle()
{
testcase("Lifecycle");
using namespace jtx;
// Create 3 loan brokers: one for XRP, one for an IOU, and one for
// an MPT. That'll require three corresponding SAVs.
Env env(*this, all);
Account const issuer{"issuer"};
// For simplicity, lender will be the sole actor for the vault &
// brokers.
Account const lender{"lender"};
// Borrower only wants to borrow
Account const borrower{"borrower"};
// Evan will attempt to be naughty
Account const evan{"evan"};
// Do not fund alice
Account const alice{"alice"};
// Fund the accounts and trust lines with the same amount so that
// tests can use the same values regardless of the asset.
env.fund(XRP(100'000'000), issuer, noripple(lender, borrower, evan));
env.close();
// Create assets
PrettyAsset const xrpAsset{xrpIssue(), 1'000'000};
PrettyAsset const iouAsset = issuer[iouCurrency];
env(trust(lender, iouAsset(10'000'000)));
env(trust(borrower, iouAsset(10'000'000)));
env(trust(evan, iouAsset(10'000'000)));
env(pay(issuer, evan, iouAsset(1'000'000)));
env(pay(issuer, lender, iouAsset(10'000'000)));
// Fund the borrower with enough to cover interest and fees
env(pay(issuer, borrower, iouAsset(10'000)));
env.close();
MPTTester mptt{env, issuer, mptInitNoFund};
mptt.create({.flags = tfMPTCanClawback | tfMPTCanTransfer | tfMPTCanLock});
// Scale the MPT asset a little bit so we can get some interest
PrettyAsset const mptAsset{mptt.issuanceID(), 100};
mptt.authorize({.account = lender});
mptt.authorize({.account = borrower});
mptt.authorize({.account = evan});
env(pay(issuer, lender, mptAsset(10'000'000)));
env(pay(issuer, evan, mptAsset(1'000'000)));
// Fund the borrower with enough to cover interest and fees
env(pay(issuer, borrower, mptAsset(10'000)));
env.close();
std::array const assets{iouAsset, xrpAsset, mptAsset};
// Create vaults and loan brokers
std::vector<BrokerInfo> brokers;
brokers.reserve(assets.size());
for (auto const& asset : assets)
{
brokers.emplace_back(createVaultAndBroker(
env, asset, lender, BrokerParameters{.data = "spam spam spam spam"}));
}
// Create and update Loans
for (auto const& broker : brokers)
{
for (int amountExponent = 3; amountExponent >= 3; --amountExponent)
{
Number const loanAmount{1, amountExponent};
for (int interestExponent = 0; interestExponent >= 0; --interestExponent)
{
testCaseWrapper(env, mptt, assets, broker, loanAmount, interestExponent);
}
}
if (auto brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle))
{
BEAST_EXPECT(brokerSle->at(sfOwnerCount) == 0);
BEAST_EXPECT(brokerSle->at(sfDebtTotal) == 0);
auto const coverAvailable = brokerSle->at(sfCoverAvailable);
env(loanBroker::coverWithdraw(
lender, broker.brokerID, STAmount(broker.asset, coverAvailable)));
env.close();
brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle && brokerSle->at(sfCoverAvailable) == 0);
}
// Verify we can delete the loan broker
env(loanBroker::del(lender, broker.brokerID));
env.close();
}
}
void
testSelfLoan()
{
testcase << "Self Loan";
using namespace jtx;
using namespace std::chrono_literals;
// Create 3 loan brokers: one for XRP, one for an IOU, and one for
// an MPT. That'll require three corresponding SAVs.
Env env(*this, all);
Account const issuer{"issuer"};
// For simplicity, lender will be the sole actor for the vault &
// brokers.
Account const lender{"lender"};
// Fund the accounts and trust lines with the same amount so that
// tests can use the same values regardless of the asset.
env.fund(XRP(100'000'000), issuer, noripple(lender));
env.close();
// Use an XRP asset for simplicity
PrettyAsset const xrpAsset{xrpIssue(), 1'000'000};
// Create vaults and loan brokers
BrokerInfo broker{createVaultAndBroker(env, xrpAsset, lender)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
// The LoanSet json can be created without a counterparty signature,
// but it will not pass preflight
auto createJson = env.json(
set(lender, broker.brokerID, broker.asset(principalRequest).value()), fee(loanSetFee));
env(createJson, ter(temBAD_SIGNER));
// Adding an empty counterparty signature object also fails, but
// at the RPC level.
createJson = env.json(createJson, json(sfCounterpartySignature, Json::objectValue));
env(createJson, ter(telENV_RPC_FAILED));
if (auto const jt = env.jt(createJson); BEAST_EXPECT(jt.stx))
{
Serializer s;
jt.stx->add(s);
auto const jr = env.rpc("submit", strHex(s.slice()));
BEAST_EXPECT(jr.isMember(jss::result));
auto const jResult = jr[jss::result];
BEAST_EXPECT(jResult[jss::error] == "invalidTransaction");
BEAST_EXPECT(
jResult[jss::error_exception] ==
"fails local checks: Transaction has bad signature.");
}
// Copy the transaction signature into the counterparty signature.
Json::Value counterpartyJson{Json::objectValue};
counterpartyJson[sfTxnSignature] = createJson[sfTxnSignature];
counterpartyJson[sfSigningPubKey] = createJson[sfSigningPubKey];
if (!BEAST_EXPECT(!createJson.isMember(jss::Signers)))
counterpartyJson[sfSigners] = createJson[sfSigners];
// The duplicated signature works
createJson = env.json(createJson, json(sfCounterpartySignature, counterpartyJson));
env(createJson);
env.close();
auto const startDate = env.current()->header().parentCloseTime;
// Loan is successfully created
{
auto const res = env.rpc("account_objects", lender.human());
auto const objects = res[jss::result][jss::account_objects];
std::map<std::string, std::size_t> types;
BEAST_EXPECT(objects.size() == 4);
for (auto const& object : objects)
{
++types[object[sfLedgerEntryType].asString()];
}
BEAST_EXPECT(types.size() == 4);
for (std::string const type : {"MPToken", "Vault", "LoanBroker", "Loan"})
{
BEAST_EXPECT(types[type] == 1);
}
}
auto const loanID = [&]() {
Json::Value params(Json::objectValue);
params[jss::account] = lender.human();
params[jss::type] = "Loan";
auto const res = env.rpc("json", "account_objects", to_string(params));
auto const objects = res[jss::result][jss::account_objects];
BEAST_EXPECT(objects.size() == 1);
auto const loan = objects[0u];
BEAST_EXPECT(loan[sfBorrower] == lender.human());
// soeDEFAULT fields are not returned if they're in the default
// state
BEAST_EXPECT(!loan.isMember(sfCloseInterestRate));
BEAST_EXPECT(!loan.isMember(sfClosePaymentFee));
BEAST_EXPECT(loan[sfFlags] == 0);
BEAST_EXPECT(loan[sfGracePeriod] == 60);
BEAST_EXPECT(!loan.isMember(sfInterestRate));
BEAST_EXPECT(!loan.isMember(sfLateInterestRate));
BEAST_EXPECT(!loan.isMember(sfLatePaymentFee));
BEAST_EXPECT(loan[sfLoanBrokerID] == to_string(broker.brokerID));
BEAST_EXPECT(!loan.isMember(sfLoanOriginationFee));
BEAST_EXPECT(loan[sfLoanSequence] == 1);
BEAST_EXPECT(!loan.isMember(sfLoanServiceFee));
BEAST_EXPECT(loan[sfNextPaymentDueDate] == loan[sfStartDate].asUInt() + 60);
BEAST_EXPECT(!loan.isMember(sfOverpaymentFee));
BEAST_EXPECT(!loan.isMember(sfOverpaymentInterestRate));
BEAST_EXPECT(loan[sfPaymentInterval] == 60);
BEAST_EXPECT(loan[sfPeriodicPayment] == "1000000000");
BEAST_EXPECT(loan[sfPaymentRemaining] == 1);
BEAST_EXPECT(!loan.isMember(sfPreviousPaymentDueDate));
BEAST_EXPECT(loan[sfPrincipalOutstanding] == "1000000000");
BEAST_EXPECT(loan[sfTotalValueOutstanding] == "1000000000");
BEAST_EXPECT(!loan.isMember(sfLoanScale));
BEAST_EXPECT(loan[sfStartDate].asUInt() == startDate.time_since_epoch().count());
return loan["index"].asString();
}();
auto const loanKeylet{keylet::loan(uint256{std::string_view(loanID)})};
env.close(startDate);
// Make a payment
env(pay(lender, loanKeylet.key, broker.asset(1000)));
}
void
testBatchBypassCounterparty()
{
// From FIND-001
testcase << "Batch Bypass Counterparty";
bool const lendingBatchEnabled = !std::any_of(
Batch::disabledTxTypes.begin(), Batch::disabledTxTypes.end(), [](auto const& disabled) {
return disabled == ttLOAN_BROKER_SET;
});
using namespace jtx;
using namespace std::chrono_literals;
Env env(*this, all);
Account const lender{"lender"};
Account const borrower{"borrower"};
BrokerParameters brokerParams;
env.fund(XRP(brokerParams.vaultDeposit * 100), lender, borrower);
env.close();
PrettyAsset const xrpAsset{xrpIssue(), 1'000'000};
BrokerInfo broker{createVaultAndBroker(env, xrpAsset, lender, brokerParams)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto forgedLoanSet = set(borrower, broker.brokerID, principalRequest, 0);
Json::Value randomData{Json::objectValue};
randomData[jss::SigningPubKey] = Json::StaticString{"2600"};
Json::Value sigObject{Json::objectValue};
sigObject[jss::SigningPubKey] = strHex(lender.pk().slice());
Serializer ss;
ss.add32(HashPrefix::txSign);
parse(randomData).addWithoutSigningFields(ss);
auto const sig = xrpl::sign(borrower.pk(), borrower.sk(), ss.slice());
sigObject[jss::TxnSignature] = strHex(Slice{sig.data(), sig.size()});
forgedLoanSet[Json::StaticString{"CounterpartySignature"}] = sigObject;
// ? Fails because the lender hasn't signed the tx
env(env.json(forgedLoanSet, fee(loanSetFee)), ter(telENV_RPC_FAILED));
auto const seq = env.seq(borrower);
auto const batchFee = batch::calcBatchFee(env, 1, 2);
// ! Should fail because the lender hasn't signed the tx
env(batch::outer(borrower, seq, batchFee, tfAllOrNothing),
batch::inner(forgedLoanSet, seq + 1),
batch::inner(pay(borrower, lender, XRP(1)), seq + 2),
ter(lendingBatchEnabled ? temBAD_SIGNATURE : temINVALID_INNER_BATCH));
env.close();
// ? Check that the loan was NOT created
{
Json::Value params(Json::objectValue);
params[jss::account] = borrower.human();
params[jss::type] = "Loan";
auto const res = env.rpc("json", "account_objects", to_string(params));
auto const objects = res[jss::result][jss::account_objects];
BEAST_EXPECT(objects.size() == 0);
}
}
void
testWrongMaxDebtBehavior()
{
// From FIND-003
testcase << "Wrong Max Debt Behavior";
using namespace jtx;
using namespace std::chrono_literals;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
BrokerParameters brokerParams{.debtMax = 0};
env.fund(XRP(brokerParams.vaultDeposit * 100), issuer, noripple(lender));
env.close();
PrettyAsset const xrpAsset{xrpIssue(), 1'000'000};
BrokerInfo broker{createVaultAndBroker(env, xrpAsset, lender, brokerParams)};
if (auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle))
{
BEAST_EXPECT(brokerSle->at(sfDebtMaximum) == 0);
}
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto createJson = env.json(set(lender, broker.brokerID, principalRequest), fee(loanSetFee));
Json::Value counterpartyJson{Json::objectValue};
counterpartyJson[sfTxnSignature] = createJson[sfTxnSignature];
counterpartyJson[sfSigningPubKey] = createJson[sfSigningPubKey];
if (!BEAST_EXPECT(!createJson.isMember(jss::Signers)))
counterpartyJson[sfSigners] = createJson[sfSigners];
createJson = env.json(createJson, json(sfCounterpartySignature, counterpartyJson));
env(createJson);
env.close();
}
void
testLoanPayComputePeriodicPaymentValidRateInvariant()
{
// From FIND-012
testcase << "LoanPay xrpl::detail::computePeriodicPayment : "
"valid rate";
using namespace jtx;
using namespace std::chrono_literals;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
BrokerParameters brokerParams;
env.fund(XRP(brokerParams.vaultDeposit * 100), issuer, lender, borrower);
env.close();
PrettyAsset const xrpAsset{xrpIssue(), 1'000'000};
BrokerInfo broker{createVaultAndBroker(env, xrpAsset, lender, brokerParams)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{640562, -5};
Number const serviceFee{2462611968};
std::uint32_t const numPayments{4294967295 / 800};
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
loanServiceFee(serviceFee),
paymentTotal(numPayments),
json(sfCounterpartySignature, Json::objectValue));
createJson["CloseInterestRate"] = 55374;
createJson["ClosePaymentFee"] = "3825205248";
createJson["LatePaymentFee"] = "237";
createJson["LoanOriginationFee"] = "0";
createJson["OverpaymentFee"] = 35167;
createJson["OverpaymentInterestRate"] = 1360;
createJson["PaymentInterval"] = 727;
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
// Fails in preclaim because principal requested can't be
// represented as XRP
env(createJson, ter(tecPRECISION_LOSS));
env.close();
BEAST_EXPECT(!env.le(keylet));
Number const actualPrincipal{6};
createJson[sfPrincipalRequested] = actualPrincipal;
createJson.removeMember(sfSequence.jsonName);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
// Fails in doApply because the payment is too small to be
// represented as XRP.
env(createJson, ter(tecPRECISION_LOSS));
env.close();
}
void
testRPC()
{
// This will expand as more test cases are added. Some functionality
// is tested in other test functions.
testcase("RPC");
using namespace jtx;
Env env(*this, all);
auto lowerFee = [&]() {
// Run the local fee back down.
while (env.app().getFeeTrack().lowerLocalFee())
;
};
auto const baseFee = env.current()->fees().base;
Account const alice{"alice"};
std::string const borrowerPass = "borrower";
Account borrower{borrowerPass, KeyType::ed25519};
auto const lenderPass = "lender";
Account lender{lenderPass, KeyType::ed25519};
env.fund(XRP(1'000'000), alice, lender, borrower);
env.close();
env(noop(lender));
env(noop(lender));
env(noop(lender));
env(noop(lender));
env(noop(lender));
env.close();
{
testcase("RPC AccountSet");
Json::Value txJson{Json::objectValue};
txJson[sfTransactionType] = "AccountSet";
txJson[sfAccount] = borrower.human();
auto const signParams = [&]() {
Json::Value signParams{Json::objectValue};
signParams[jss::passphrase] = borrowerPass;
signParams[jss::key_type] = "ed25519";
signParams[jss::tx_json] = txJson;
return signParams;
}();
auto const jSign = env.rpc("json", "sign", to_string(signParams));
BEAST_EXPECT(jSign.isMember(jss::result) && jSign[jss::result].isMember(jss::tx_json));
auto txSignResult = jSign[jss::result][jss::tx_json];
auto txSignBlob = jSign[jss::result][jss::tx_blob].asString();
txSignResult.removeMember(jss::hash);
auto const jtx = env.jt(txJson, sig(borrower));
BEAST_EXPECT(txSignResult == jtx.jv);
lowerFee();
auto const jSubmit = env.rpc("submit", txSignBlob);
BEAST_EXPECT(
jSubmit.isMember(jss::result) &&
jSubmit[jss::result].isMember(jss::engine_result) &&
jSubmit[jss::result][jss::engine_result].asString() == "tesSUCCESS");
lowerFee();
env(jtx.jv, sig(none), seq(none), fee(none), ter(tefPAST_SEQ));
}
{
testcase("RPC LoanSet - illegal signature_target");
Json::Value txJson{Json::objectValue};
txJson[sfTransactionType] = "AccountSet";
txJson[sfAccount] = borrower.human();
auto const borrowerSignParams = [&]() {
Json::Value params{Json::objectValue};
params[jss::passphrase] = borrowerPass;
params[jss::key_type] = "ed25519";
params[jss::signature_target] = "Destination";
params[jss::tx_json] = txJson;
return params;
}();
auto const jSignBorrower = env.rpc("json", "sign", to_string(borrowerSignParams));
BEAST_EXPECT(
jSignBorrower.isMember(jss::result) &&
jSignBorrower[jss::result].isMember(jss::error) &&
jSignBorrower[jss::result][jss::error] == "invalidParams" &&
jSignBorrower[jss::result].isMember(jss::error_message) &&
jSignBorrower[jss::result][jss::error_message] == "Destination");
}
{
testcase("RPC LoanSet - sign and submit borrower initiated");
// 1. Borrower creates the transaction
Json::Value txJson{Json::objectValue};
txJson[sfTransactionType] = "LoanSet";
txJson[sfAccount] = borrower.human();
txJson[sfCounterparty] = lender.human();
txJson[sfLoanBrokerID] =
"FF924CD18A236C2B49CF8E80A351CEAC6A10171DC9F110025646894FEC"
"F83F"
"5C";
txJson[sfPrincipalRequested] = "100000000";
txJson[sfPaymentTotal] = 10000;
txJson[sfPaymentInterval] = 3600;
txJson[sfGracePeriod] = 300;
txJson[sfFlags] = 65536; // tfLoanOverpayment
txJson[sfFee] = to_string(24 * baseFee / 10);
// 2. Borrower signs the transaction
auto const borrowerSignParams = [&]() {
Json::Value params{Json::objectValue};
params[jss::passphrase] = borrowerPass;
params[jss::key_type] = "ed25519";
params[jss::tx_json] = txJson;
return params;
}();
auto const jSignBorrower = env.rpc("json", "sign", to_string(borrowerSignParams));
BEAST_EXPECTS(
jSignBorrower.isMember(jss::result) &&
jSignBorrower[jss::result].isMember(jss::tx_json),
to_string(jSignBorrower));
auto const txBorrowerSignResult = jSignBorrower[jss::result][jss::tx_json];
auto const txBorrowerSignBlob = jSignBorrower[jss::result][jss::tx_blob].asString();
// 2a. Borrower attempts to submit the transaction. It doesn't
// work
{
lowerFee();
auto const jSubmitBlob = env.rpc("submit", txBorrowerSignBlob);
BEAST_EXPECT(jSubmitBlob.isMember(jss::result));
auto const jSubmitBlobResult = jSubmitBlob[jss::result];
BEAST_EXPECT(jSubmitBlobResult.isMember(jss::tx_json));
// Transaction fails because the CounterpartySignature is
// missing
BEAST_EXPECT(
jSubmitBlobResult.isMember(jss::engine_result) &&
jSubmitBlobResult[jss::engine_result].asString() == "temBAD_SIGNER");
}
// 3. Borrower sends the signed transaction to the lender
// 4. Lender signs the transaction
auto const lenderSignParams = [&]() {
Json::Value params{Json::objectValue};
params[jss::passphrase] = lenderPass;
params[jss::key_type] = "ed25519";
params[jss::signature_target] = "CounterpartySignature";
params[jss::tx_json] = txBorrowerSignResult;
return params;
}();
auto const jSignLender = env.rpc("json", "sign", to_string(lenderSignParams));
BEAST_EXPECT(
jSignLender.isMember(jss::result) &&
jSignLender[jss::result].isMember(jss::tx_json));
auto const txLenderSignResult = jSignLender[jss::result][jss::tx_json];
auto const txLenderSignBlob = jSignLender[jss::result][jss::tx_blob].asString();
// 5. Lender submits the signed transaction blob
lowerFee();
auto const jSubmitBlob = env.rpc("submit", txLenderSignBlob);
BEAST_EXPECT(jSubmitBlob.isMember(jss::result));
auto const jSubmitBlobResult = jSubmitBlob[jss::result];
BEAST_EXPECT(jSubmitBlobResult.isMember(jss::tx_json));
auto const jSubmitBlobTx = jSubmitBlobResult[jss::tx_json];
// To get far enough to return tecNO_ENTRY means that the
// signatures all validated. Of course the transaction won't
// succeed because no Vault or Broker were created.
BEAST_EXPECTS(
jSubmitBlobResult.isMember(jss::engine_result) &&
jSubmitBlobResult[jss::engine_result].asString() == "tecNO_ENTRY",
to_string(jSubmitBlobResult));
BEAST_EXPECT(
!jSubmitBlob.isMember(jss::error) && !jSubmitBlobResult.isMember(jss::error));
// 4-alt. Lender submits the transaction json originally
// received from the Borrower. It gets signed, but is now a
// duplicate, so fails. Borrower could done this instead of
// steps 4 and 5.
lowerFee();
auto const jSubmitJson = env.rpc("json", "submit", to_string(lenderSignParams));
BEAST_EXPECT(jSubmitJson.isMember(jss::result));
auto const jSubmitJsonResult = jSubmitJson[jss::result];
BEAST_EXPECT(jSubmitJsonResult.isMember(jss::tx_json));
auto const jSubmitJsonTx = jSubmitJsonResult[jss::tx_json];
// Since the previous tx claimed a fee, this duplicate is not
// going anywhere
BEAST_EXPECTS(
jSubmitJsonResult.isMember(jss::engine_result) &&
jSubmitJsonResult[jss::engine_result].asString() == "tefPAST_SEQ",
to_string(jSubmitJsonResult));
BEAST_EXPECT(
!jSubmitJson.isMember(jss::error) && !jSubmitJsonResult.isMember(jss::error));
BEAST_EXPECT(jSubmitBlobTx == jSubmitJsonTx);
}
{
testcase("RPC LoanSet - sign and submit lender initiated");
// 1. Lender creates the transaction
Json::Value txJson{Json::objectValue};
txJson[sfTransactionType] = "LoanSet";
txJson[sfAccount] = lender.human();
txJson[sfCounterparty] = borrower.human();
txJson[sfLoanBrokerID] =
"FF924CD18A236C2B49CF8E80A351CEAC6A10171DC9F110025646894FEC"
"F83F"
"5C";
txJson[sfPrincipalRequested] = "100000000";
txJson[sfPaymentTotal] = 10000;
txJson[sfPaymentInterval] = 3600;
txJson[sfGracePeriod] = 300;
txJson[sfFlags] = 65536; // tfLoanOverpayment
txJson[sfFee] = to_string(24 * baseFee / 10);
// 2. Lender signs the transaction
auto const lenderSignParams = [&]() {
Json::Value params{Json::objectValue};
params[jss::passphrase] = lenderPass;
params[jss::key_type] = "ed25519";
params[jss::tx_json] = txJson;
return params;
}();
auto const jSignLender = env.rpc("json", "sign", to_string(lenderSignParams));
BEAST_EXPECT(
jSignLender.isMember(jss::result) &&
jSignLender[jss::result].isMember(jss::tx_json));
auto const txLenderSignResult = jSignLender[jss::result][jss::tx_json];
auto const txLenderSignBlob = jSignLender[jss::result][jss::tx_blob].asString();
// 2a. Lender attempts to submit the transaction. It doesn't
// work
{
lowerFee();
auto const jSubmitBlob = env.rpc("submit", txLenderSignBlob);
BEAST_EXPECT(jSubmitBlob.isMember(jss::result));
auto const jSubmitBlobResult = jSubmitBlob[jss::result];
BEAST_EXPECT(jSubmitBlobResult.isMember(jss::tx_json));
// Transaction fails because the CounterpartySignature is
// missing
BEAST_EXPECT(
jSubmitBlobResult.isMember(jss::engine_result) &&
jSubmitBlobResult[jss::engine_result].asString() == "temBAD_SIGNER");
}
// 3. Lender sends the signed transaction to the Borrower
// 4. Borrower signs the transaction
auto const borrowerSignParams = [&]() {
Json::Value params{Json::objectValue};
params[jss::passphrase] = borrowerPass;
params[jss::key_type] = "ed25519";
params[jss::signature_target] = "CounterpartySignature";
params[jss::tx_json] = txLenderSignResult;
return params;
}();
auto const jSignBorrower = env.rpc("json", "sign", to_string(borrowerSignParams));
BEAST_EXPECT(
jSignBorrower.isMember(jss::result) &&
jSignBorrower[jss::result].isMember(jss::tx_json));
auto const txBorrowerSignResult = jSignBorrower[jss::result][jss::tx_json];
auto const txBorrowerSignBlob = jSignBorrower[jss::result][jss::tx_blob].asString();
// 5. Borrower submits the signed transaction blob
lowerFee();
auto const jSubmitBlob = env.rpc("submit", txBorrowerSignBlob);
BEAST_EXPECT(jSubmitBlob.isMember(jss::result));
auto const jSubmitBlobResult = jSubmitBlob[jss::result];
BEAST_EXPECT(jSubmitBlobResult.isMember(jss::tx_json));
auto const jSubmitBlobTx = jSubmitBlobResult[jss::tx_json];
// To get far enough to return tecNO_ENTRY means that the
// signatures all validated. Of course the transaction won't
// succeed because no Vault or Broker were created.
BEAST_EXPECTS(
jSubmitBlobResult.isMember(jss::engine_result) &&
jSubmitBlobResult[jss::engine_result].asString() == "tecNO_ENTRY",
to_string(jSubmitBlobResult));
BEAST_EXPECT(
!jSubmitBlob.isMember(jss::error) && !jSubmitBlobResult.isMember(jss::error));
// 4-alt. Borrower submits the transaction json originally
// received from the Lender. It gets signed, but is now a
// duplicate, so fails. Lender could done this instead of steps
// 4 and 5.
lowerFee();
auto const jSubmitJson = env.rpc("json", "submit", to_string(borrowerSignParams));
BEAST_EXPECT(jSubmitJson.isMember(jss::result));
auto const jSubmitJsonResult = jSubmitJson[jss::result];
BEAST_EXPECT(jSubmitJsonResult.isMember(jss::tx_json));
auto const jSubmitJsonTx = jSubmitJsonResult[jss::tx_json];
// Since the previous tx claimed a fee, this duplicate is not
// going anywhere
BEAST_EXPECTS(
jSubmitJsonResult.isMember(jss::engine_result) &&
jSubmitJsonResult[jss::engine_result].asString() == "tefPAST_SEQ",
to_string(jSubmitJsonResult));
BEAST_EXPECT(
!jSubmitJson.isMember(jss::error) && !jSubmitJsonResult.isMember(jss::error));
BEAST_EXPECT(jSubmitBlobTx == jSubmitJsonTx);
}
}
void
testServiceFeeOnBrokerDeepFreeze()
{
testcase << "Service Fee On Broker Deep Freeze";
using namespace jtx;
using namespace loan;
Account const issuer("issuer");
Account const borrower("borrower");
Account const broker("broker");
auto const IOU = issuer["IOU"];
for (bool const deepFreeze : {true, false})
{
Env env(*this);
auto getCoverBalance = [&](BrokerInfo const& brokerInfo, auto const& accountField) {
if (auto const le = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(le))
{
auto const account = le->at(accountField);
if (auto const sleLine = env.le(keylet::line(account, IOU));
BEAST_EXPECT(sleLine))
{
STAmount balance = sleLine->at(sfBalance);
if (account > issuer.id())
balance.negate();
return balance;
}
}
return STAmount{IOU};
};
env.fund(XRP(20'000), issuer, broker, borrower);
env.close();
env(trust(broker, IOU(20'000'000)));
env(pay(issuer, broker, IOU(10'000'000)));
env.close();
auto const brokerInfo = createVaultAndBroker(env, IOU, broker);
BEAST_EXPECT(getCoverBalance(brokerInfo, sfAccount) == IOU(1'000));
auto const keylet = keylet::loan(brokerInfo.brokerID, 1);
env(set(borrower, brokerInfo.brokerID, 10'000),
sig(sfCounterpartySignature, broker),
loanServiceFee(IOU(100).value()),
paymentInterval(100),
fee(XRP(100)));
env.close();
env(trust(borrower, IOU(20'000'000)));
// The borrower increases their limit and acquires some IOU so
// they can pay interest
env(pay(issuer, borrower, IOU(500)));
env.close();
if (auto const le = env.le(keylet::loan(keylet.key)); BEAST_EXPECT(le))
{
if (deepFreeze)
{
env(trust(issuer, broker["IOU"](0), tfSetFreeze | tfSetDeepFreeze));
env.close();
}
env(pay(borrower, keylet.key, IOU(10'100)), fee(XRP(100)));
env.close();
if (deepFreeze)
{
// The fee goes to the broker pseudo-account
BEAST_EXPECT(getCoverBalance(brokerInfo, sfAccount) == IOU(1'100));
BEAST_EXPECT(getCoverBalance(brokerInfo, sfOwner) == IOU(8'999'000));
}
else
{
// The fee goes to the broker account
BEAST_EXPECT(getCoverBalance(brokerInfo, sfOwner) == IOU(8'999'100));
BEAST_EXPECT(getCoverBalance(brokerInfo, sfAccount) == IOU(1'000));
}
}
};
}
void
testIssuerLoan()
{
testcase << "Issuer Loan";
using namespace jtx;
using namespace loan;
Account const issuer("issuer");
Account const borrower = issuer;
Account const lender("lender");
Env env(*this);
env.fund(XRP(1'000), issuer, lender);
std::int64_t constexpr issuerBalance = 10'000'000;
MPTTester asset({.env = env, .issuer = issuer, .holders = {lender}, .pay = issuerBalance});
BrokerParameters const brokerParams{
.debtMax = 200,
};
auto const broker = createVaultAndBroker(env, asset, lender, brokerParams);
auto const loanSetFee = fee(env.current()->fees().base * 2);
// Create Loan
env(set(borrower, broker.brokerID, 200), sig(sfCounterpartySignature, lender), loanSetFee);
env.close();
// Issuer should not create MPToken
BEAST_EXPECT(!env.le(keylet::mptoken(asset.issuanceID(), issuer)));
// Issuer "borrowed" 200, OutstandingAmount decreased by 200
BEAST_EXPECT(env.balance(issuer, asset) == asset(-issuerBalance + 200));
// Pay Loan
auto const loanKeylet = keylet::loan(broker.brokerID, 1);
env(pay(borrower, loanKeylet.key, asset(200)));
env.close();
// Issuer "re-payed" 200, OutstandingAmount increased by 200
BEAST_EXPECT(env.balance(issuer, asset) == asset(-issuerBalance));
}
void
testInvalidLoanDelete()
{
testcase("Invalid LoanDelete");
using namespace jtx;
using namespace loan;
// preflight: temINVALID, LoanID == zero
{
Account const alice{"alice"};
Env env(*this);
env.fund(XRP(1'000), alice);
env.close();
env(del(alice, beast::zero), ter(temINVALID));
}
}
void
testInvalidLoanManage()
{
testcase("Invalid LoanManage");
using namespace jtx;
using namespace loan;
// preflight: temINVALID, LoanID == zero
{
Account const alice{"alice"};
Env env(*this);
env.fund(XRP(1'000), alice);
env.close();
env(manage(alice, beast::zero, tfLoanDefault), ter(temINVALID));
}
}
void
testInvalidLoanPay()
{
testcase("Invalid LoanPay");
using namespace jtx;
using namespace loan;
Account const lender{"lender"};
Account const issuer{"issuer"};
Account const borrower{"borrower"};
auto const IOU = issuer["IOU"];
// preclaim
Env env(*this);
env.fund(XRP(1'000), lender, issuer, borrower);
env(trust(lender, IOU(10'000'000)));
env(pay(issuer, lender, IOU(5'000'000)));
BrokerInfo brokerInfo{createVaultAndBroker(env, issuer["IOU"], lender)};
auto const loanSetFee = fee(env.current()->fees().base * 2);
STAmount const debtMaximumRequest = brokerInfo.asset(1'000).value();
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee);
env.close();
std::uint32_t const loanSequence = 1;
auto const loanKeylet = keylet::loan(brokerInfo.brokerID, loanSequence);
env(fset(issuer, asfGlobalFreeze));
env.close();
// preclaim: tecFROZEN
env(pay(borrower, loanKeylet.key, debtMaximumRequest), ter(tecFROZEN));
env.close();
env(fclear(issuer, asfGlobalFreeze));
env.close();
auto const pseudoBroker = [&]() -> std::optional<Account> {
if (auto brokerSle = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(brokerSle))
{
return Account{"pseudo", brokerSle->at(sfAccount)};
}
return std::nullopt;
}();
if (!pseudoBroker)
return;
// Lender and pseudoaccount must both be frozen
env(trust(issuer, lender["IOU"](1'000), lender, tfSetFreeze | tfSetDeepFreeze));
env(trust(
issuer, (*pseudoBroker)["IOU"](1'000), *pseudoBroker, tfSetFreeze | tfSetDeepFreeze));
env.close();
// preclaim: tecFROZEN due to deep frozen
env(pay(borrower, loanKeylet.key, debtMaximumRequest), ter(tecFROZEN));
env.close();
// Only one needs to be unfrozen
env(trust(issuer, lender["IOU"](1'000), tfClearFreeze | tfClearDeepFreeze));
env.close();
// The payment is late by this point
env(pay(borrower, loanKeylet.key, debtMaximumRequest), ter(tecEXPIRED));
env.close();
env(pay(borrower, loanKeylet.key, debtMaximumRequest, tfLoanLatePayment));
env.close();
// preclaim: tecKILLED
// note that tecKILLED in loanMakePayment()
// doesn't happen because of the preclaim check.
env(pay(borrower, loanKeylet.key, debtMaximumRequest), ter(tecKILLED));
}
void
testInvalidLoanSet()
{
testcase("Invalid LoanSet");
using namespace jtx;
using namespace loan;
Account const lender{"lender"};
Account const issuer{"issuer"};
Account const borrower{"borrower"};
auto const IOU = issuer["IOU"];
auto testWrapper = [&](auto&& test) {
Env env(*this);
env.fund(XRP(1'000), lender, issuer, borrower);
env(trust(lender, IOU(10'000'000)));
env(pay(issuer, lender, IOU(5'000'000)));
BrokerInfo brokerInfo{createVaultAndBroker(env, issuer["IOU"], lender)};
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const debtMaximumRequest = brokerInfo.asset(1'000).value();
test(env, brokerInfo, loanSetFee, debtMaximumRequest);
};
// preflight:
testWrapper([&](Env& env,
BrokerInfo const& brokerInfo,
jtx::fee const& loanSetFee,
Number const& debtMaximumRequest) {
// first temBAD_SIGNER: TODO
// invalid grace period
{
// zero grace period
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
gracePeriod(0),
loanSetFee,
ter(temINVALID));
// grace period less than default minimum
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
gracePeriod(LoanSet::defaultGracePeriod - 1),
loanSetFee,
ter(temINVALID));
// grace period greater than payment interval
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
paymentInterval(120),
gracePeriod(121),
loanSetFee,
ter(temINVALID));
}
// empty/zero broker ID
{
auto jv = set(borrower, uint256{}, debtMaximumRequest);
auto testZeroBrokerID = [&](std::string const& id, std::uint32_t flags = 0) {
// empty broker ID
jv[sfLoanBrokerID] = id;
env(jv,
sig(sfCounterpartySignature, lender),
loanSetFee,
txflags(flags),
ter(temINVALID));
};
// empty broker ID
testZeroBrokerID(std::string(""));
// zero broker ID
// needs a flag to distinguish the parsed STTx from the prior
// test
testZeroBrokerID(to_string(uint256{}), tfFullyCanonicalSig);
}
// preflightCheckSigningKey() failure:
// can it happen? the signature is checked before transactor
// executes
JTx tx = env.jt(
set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee);
STTx local = *(tx.stx);
auto counterpartySig = local.getFieldObject(sfCounterpartySignature);
auto badPubKey = counterpartySig.getFieldVL(sfSigningPubKey);
badPubKey[20] ^= 0xAA;
counterpartySig.setFieldVL(sfSigningPubKey, badPubKey);
local.setFieldObject(sfCounterpartySignature, counterpartySig);
Json::Value jvResult;
jvResult[jss::tx_blob] = strHex(local.getSerializer().slice());
auto res = env.rpc("json", "submit", to_string(jvResult))["result"];
BEAST_EXPECT(
res[jss::error] == "invalidTransaction" &&
res[jss::error_exception] ==
"fails local checks: Counterparty: Invalid signature.");
});
// preclaim:
testWrapper([&](Env& env,
BrokerInfo const& brokerInfo,
jtx::fee const& loanSetFee,
Number const& debtMaximumRequest) {
// canAddHoldingFailure (IOU only, if MPT doesn't have
// MPTCanTransfer set, then can't create Vault/LoanBroker,
// and LoanSet will fail with different error
env(fclear(issuer, asfDefaultRipple));
env.close();
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(terNO_RIPPLE));
});
// doApply:
testWrapper([&](Env& env,
BrokerInfo const& brokerInfo,
jtx::fee const& loanSetFee,
Number const& debtMaximumRequest) {
auto const amt = env.balance(borrower) -
env.current()->fees().accountReserve(env.ownerCount(borrower));
env(pay(borrower, issuer, amt));
// tecINSUFFICIENT_RESERVE
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(tecINSUFFICIENT_RESERVE));
// addEmptyHolding failure
env(pay(issuer, borrower, amt));
env(fset(issuer, asfGlobalFreeze));
env.close();
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
ter(tecFROZEN));
});
}
void
testAccountSendMptMinAmountInvariant()
{
// (From FIND-006)
testcase << "LoanSet trigger xrpl::accountSendMPT : minimum amount "
"and MPT";
using namespace jtx;
using namespace std::chrono_literals;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
MPTTester mptt{env, issuer, mptInitNoFund};
mptt.create({.flags = tfMPTCanClawback | tfMPTCanTransfer | tfMPTCanLock});
PrettyAsset const mptAsset = mptt.issuanceID();
mptt.authorize({.account = lender});
mptt.authorize({.account = borrower});
env(pay(issuer, lender, mptAsset(2'000'000)));
env(pay(issuer, borrower, mptAsset(1'000)));
env.close();
BrokerInfo broker{createVaultAndBroker(env, mptAsset, lender)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
json(sfCounterpartySignature, Json::objectValue));
createJson["CloseInterestRate"] = 76671;
createJson["ClosePaymentFee"] = "2061925410";
createJson["GracePeriod"] = 434;
createJson["InterestRate"] = 50302;
createJson["LateInterestRate"] = 30322;
createJson["LatePaymentFee"] = "294427911";
createJson["LoanOriginationFee"] = "3250635102";
createJson["LoanServiceFee"] = "9557386";
createJson["OverpaymentFee"] = 51249;
createJson["OverpaymentInterestRate"] = 14304;
createJson["PaymentInterval"] = 434;
createJson["PaymentTotal"] = "2891743748";
createJson["PrincipalRequested"] = "8516.98";
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
env(createJson, ter(temINVALID));
env.close();
}
void
testLoanPayDebtDecreaseInvariant()
{
// From FIND-007
testcase << "LoanPay xrpl::LoanPay::doApply : debtDecrease "
"rounding good";
using namespace jtx;
using namespace std::chrono_literals;
using namespace Lending;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const iouAsset = issuer[iouCurrency];
auto trustLenderTx = env.json(trust(lender, iouAsset(1'000'000'000)));
env(trustLenderTx);
auto trustBorrowerTx = env.json(trust(borrower, iouAsset(1'000'000'000)));
env(trustBorrowerTx);
auto payLenderTx = pay(issuer, lender, iouAsset(100'000'000));
env(payLenderTx);
auto payIssuerTx = pay(issuer, borrower, iouAsset(1'000'000));
env(payIssuerTx);
env.close();
BrokerInfo broker{createVaultAndBroker(env, iouAsset, lender)};
using namespace loan;
auto const baseFee = env.current()->fees().base;
auto const loanSetFee = fee(baseFee * 2);
Number const principalRequest{1, 3};
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
json(sfCounterpartySignature, Json::objectValue));
createJson["ClosePaymentFee"] = "0";
createJson["GracePeriod"] = 60;
createJson["InterestRate"] = 24346;
createJson["LateInterestRate"] = 65535;
createJson["LatePaymentFee"] = "0";
createJson["LoanOriginationFee"] = "218";
createJson["LoanServiceFee"] = "0";
createJson["PaymentInterval"] = 60;
createJson["PaymentTotal"] = 5678;
createJson["PrincipalRequested"] = "9924.81";
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
env(createJson, ter(tesSUCCESS));
env.close();
auto const pseudoAcct = [&]() {
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
return Account{lender};
auto const brokerPseudo = brokerSle->at(sfAccount);
return Account("Broker pseudo-account", brokerPseudo);
}();
VerifyLoanStatus verifyLoanStatus(env, broker, pseudoAcct, keylet);
auto const originalState = getCurrentState(env, broker, keylet);
verifyLoanStatus(originalState);
Number const payment{3'269'349'176'470'588, -12};
XRPAmount const payFee{
baseFee *
((payment / originalState.periodicPayment) / loanPaymentsPerFeeIncrement + 1)};
auto loanPayTx =
env.json(pay(borrower, keylet.key, STAmount{broker.asset, payment}), fee(payFee));
BEAST_EXPECT(to_string(payment) == "3269.349176470588");
env(loanPayTx, ter(tesSUCCESS));
env.close();
auto const newState = getCurrentState(env, broker, keylet);
BEAST_EXPECT(
isRounded(broker.asset, newState.managementFeeOutstanding, originalState.loanScale));
BEAST_EXPECT(newState.managementFeeOutstanding < originalState.managementFeeOutstanding);
BEAST_EXPECT(isRounded(broker.asset, newState.totalValue, originalState.loanScale));
BEAST_EXPECT(
isRounded(broker.asset, newState.principalOutstanding, originalState.loanScale));
}
void
testLoanPayComputePeriodicPaymentValidTotalInterestInvariant()
{
// From FIND-010
testcase << "xrpl::loanComputePaymentParts : valid total interest";
using namespace jtx;
using namespace std::chrono_literals;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const iouAsset = issuer[iouCurrency];
auto trustLenderTx = env.json(trust(lender, iouAsset(1'000'000'000)));
env(trustLenderTx);
auto trustBorrowerTx = env.json(trust(borrower, iouAsset(1'000'000'000)));
env(trustBorrowerTx);
auto payLenderTx = pay(issuer, lender, iouAsset(100'000'000));
env(payLenderTx);
auto payIssuerTx = pay(issuer, borrower, iouAsset(1'000'000));
env(payIssuerTx);
env.close();
BrokerInfo broker{createVaultAndBroker(env, iouAsset, lender)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
json(sfCounterpartySignature, Json::objectValue));
createJson["CloseInterestRate"] = 47299;
createJson["ClosePaymentFee"] = "3985819770";
createJson["InterestRate"] = 92;
createJson["LatePaymentFee"] = "3866894865";
createJson["LoanOriginationFee"] = "0";
createJson["LoanServiceFee"] = "2348810240";
createJson["OverpaymentFee"] = 58545;
createJson["PaymentInterval"] = 60;
createJson["PaymentTotal"] = 1;
createJson["PrincipalRequested"] = "0.000763058";
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
env(createJson);
env.close();
auto loanPayTx = env.json(pay(borrower, keylet.key, STAmount{broker.asset, Number{}}));
loanPayTx["Amount"]["value"] = "0.000281284125490196";
env(loanPayTx, ter(tecINSUFFICIENT_PAYMENT));
env.close();
}
void
testDosLoanPay()
{
// From FIND-005
testcase << "DoS LoanPay";
using namespace jtx;
using namespace std::chrono_literals;
using namespace Lending;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const iouAsset = issuer[iouCurrency];
env(trust(lender, iouAsset(100'000'000)));
env(trust(borrower, iouAsset(100'000'000)));
env(pay(issuer, lender, iouAsset(10'000'000)));
env(pay(issuer, borrower, iouAsset(1'000)));
env.close();
BrokerInfo broker{createVaultAndBroker(env, iouAsset, lender)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto const baseFee = env.current()->fees().base;
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
json(sfCounterpartySignature, Json::objectValue));
createJson["ClosePaymentFee"] = "0";
createJson["GracePeriod"] = 60;
createJson["InterestRate"] = 20930;
createJson["LateInterestRate"] = 77049;
createJson["LatePaymentFee"] = "0";
createJson["LoanServiceFee"] = "0";
createJson["OverpaymentFee"] = 7;
createJson["OverpaymentInterestRate"] = 66653;
createJson["PaymentInterval"] = 60;
createJson["PaymentTotal"] = 3239184;
createJson["PrincipalRequested"] = "3959.37";
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
env(createJson, ter(tesSUCCESS));
env.close();
auto const stateBefore = getCurrentState(env, broker, keylet);
BEAST_EXPECT(stateBefore.paymentRemaining == 3239184);
BEAST_EXPECT(stateBefore.paymentRemaining > loanMaximumPaymentsPerTransaction);
auto loanPayTx = env.json(pay(borrower, keylet.key, STAmount{broker.asset, Number{}}));
Number const amount{395937, -2};
loanPayTx["Amount"]["value"] = to_string(amount);
XRPAmount const payFee{
baseFee *
std::int64_t(amount / stateBefore.periodicPayment / loanPaymentsPerFeeIncrement + 1)};
env(loanPayTx, ter(tesSUCCESS), fee(payFee));
env.close();
auto const stateAfter = getCurrentState(env, broker, keylet);
BEAST_EXPECT(
stateAfter.paymentRemaining ==
stateBefore.paymentRemaining - loanMaximumPaymentsPerTransaction);
}
void
testLoanPayComputePeriodicPaymentValidTotalPrincipalPaidInvariant()
{
// From FIND-009
testcase << "xrpl::loanComputePaymentParts : totalPrincipalPaid "
"rounded";
using namespace jtx;
using namespace std::chrono_literals;
using namespace Lending;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const iouAsset = issuer[iouCurrency];
auto trustLenderTx = env.json(trust(lender, iouAsset(1'000'000'000)));
env(trustLenderTx);
auto trustBorrowerTx = env.json(trust(borrower, iouAsset(1'000'000'000)));
env(trustBorrowerTx);
auto payLenderTx = pay(issuer, lender, iouAsset(100'000'000));
env(payLenderTx);
auto payIssuerTx = pay(issuer, borrower, iouAsset(1'000'000));
env(payIssuerTx);
env.close();
BrokerInfo broker{createVaultAndBroker(env, iouAsset, lender)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
json(sfCounterpartySignature, Json::objectValue));
createJson["ClosePaymentFee"] = "0";
createJson["InterestRate"] = 24346;
createJson["LateInterestRate"] = 65535;
createJson["LatePaymentFee"] = "0";
createJson["LoanOriginationFee"] = "218";
createJson["LoanServiceFee"] = "0";
createJson["PaymentInterval"] = 60;
createJson["PaymentTotal"] = 5678;
createJson["PrincipalRequested"] = "9924.81";
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
env(createJson, ter(tesSUCCESS));
env.close();
auto const baseFee = env.current()->fees().base;
auto const stateBefore = getCurrentState(env, broker, keylet);
{
auto loanPayTx = env.json(pay(borrower, keylet.key, STAmount{broker.asset, Number{}}));
Number const amount{3074'745'058'823'529, -12};
BEAST_EXPECT(to_string(amount) == "3074.745058823529");
XRPAmount const payFee{
baseFee * (amount / stateBefore.periodicPayment / loanPaymentsPerFeeIncrement + 1)};
loanPayTx["Amount"]["value"] = to_string(amount);
env(loanPayTx, fee(payFee), ter(tesSUCCESS));
env.close();
}
{
auto loanPayTx = env.json(pay(borrower, keylet.key, STAmount{broker.asset, Number{}}));
Number const amount{6732'118'170'944'051, -12};
BEAST_EXPECT(to_string(amount) == "6732.118170944051");
XRPAmount const payFee{
baseFee * (amount / stateBefore.periodicPayment / loanPaymentsPerFeeIncrement + 1)};
loanPayTx["Amount"]["value"] = to_string(amount);
env(loanPayTx, fee(payFee), ter(tesSUCCESS));
env.close();
}
auto const stateAfter = getCurrentState(env, broker, keylet);
// Total interest outstanding is non-negative
BEAST_EXPECT(stateAfter.totalValue >= stateAfter.principalOutstanding);
// Principal paid is non-negative
BEAST_EXPECT(stateBefore.principalOutstanding >= stateAfter.principalOutstanding);
// Total value change is non-negative
BEAST_EXPECT(stateBefore.totalValue >= stateAfter.totalValue);
// Value delta is larger or same as principal delta (meaning
// non-negative interest paid)
BEAST_EXPECT(
(stateBefore.totalValue - stateAfter.totalValue) >=
(stateBefore.principalOutstanding - stateAfter.principalOutstanding));
}
void
testLoanPayComputePeriodicPaymentValidTotalInterestPaidInvariant()
{
// From FIND-008
testcase << "xrpl::loanComputePaymentParts : loanValueChange rounded";
using namespace jtx;
using namespace std::chrono_literals;
using namespace Lending;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const iouAsset = issuer[iouCurrency];
auto trustLenderTx = env.json(trust(lender, iouAsset(1'000'000'000)));
env(trustLenderTx);
auto trustBorrowerTx = env.json(trust(borrower, iouAsset(1'000'000'000)));
env(trustBorrowerTx);
auto payLenderTx = pay(issuer, lender, iouAsset(100'000'000));
env(payLenderTx);
auto payIssuerTx = pay(issuer, borrower, iouAsset(10'000'000));
env(payIssuerTx);
env.close();
BrokerInfo broker{createVaultAndBroker(env, iouAsset, lender)};
{
auto const coverDepositValue = broker.asset(broker.params.coverDeposit * 10).value();
env(loanBroker::coverDeposit(lender, broker.brokerID, coverDepositValue));
env.close();
}
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest{1, 3};
auto createJson = env.json(
set(borrower, broker.brokerID, principalRequest),
fee(loanSetFee),
json(sfCounterpartySignature, Json::objectValue));
createJson["ClosePaymentFee"] = "0";
createJson["InterestRate"] = 12833;
createJson["LateInterestRate"] = 77048;
createJson["LatePaymentFee"] = "0";
createJson["LoanOriginationFee"] = "218";
createJson["LoanServiceFee"] = "0";
createJson["PaymentInterval"] = 752;
createJson["PaymentTotal"] = 5678;
createJson["PrincipalRequested"] = "9924.81";
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
createJson = env.json(createJson, sig(sfCounterpartySignature, lender));
env(createJson, ter(tesSUCCESS));
env.close();
auto const baseFee = env.current()->fees().base;
auto const stateBefore = getCurrentState(env, broker, keylet);
BEAST_EXPECT(stateBefore.paymentRemaining == 5678);
BEAST_EXPECT(stateBefore.paymentRemaining > loanMaximumPaymentsPerTransaction);
auto loanPayTx = env.json(pay(borrower, keylet.key, STAmount{broker.asset, Number{}}));
Number const amount{9924'81, -2};
BEAST_EXPECT(to_string(amount) == "9924.81");
XRPAmount const payFee{
baseFee * (amount / stateBefore.periodicPayment / loanPaymentsPerFeeIncrement + 1)};
loanPayTx["Amount"]["value"] = to_string(amount);
env(loanPayTx, fee(payFee), ter(tesSUCCESS));
env.close();
auto const stateAfter = getCurrentState(env, broker, keylet);
BEAST_EXPECT(
stateAfter.paymentRemaining ==
stateBefore.paymentRemaining - loanMaximumPaymentsPerTransaction);
}
void
testLoanNextPaymentDueDateOverflow()
{
// For FIND-013
testcase << "Prevent nextPaymentDueDate overflow";
using namespace jtx;
using namespace std::chrono_literals;
using namespace Lending;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const iouAsset = issuer[iouCurrency];
auto trustLenderTx = env.json(trust(lender, iouAsset(1'000'000'000)));
env(trustLenderTx);
auto trustBorrowerTx = env.json(trust(borrower, iouAsset(1'000'000'000)));
env(trustBorrowerTx);
auto payLenderTx = pay(issuer, lender, iouAsset(100'000'000));
env(payLenderTx);
auto payIssuerTx = pay(issuer, borrower, iouAsset(10'000'000));
env(payIssuerTx);
env.close();
BrokerParameters const brokerParams{.debtMax = Number{0}, .coverRateMin = TenthBips32{1}};
BrokerInfo broker{createVaultAndBroker(env, iouAsset, lender, brokerParams)};
using namespace loan;
auto const loanSetFee = fee(env.current()->fees().base * 2);
using timeType = decltype(sfNextPaymentDueDate)::type::value_type;
static_assert(std::is_same_v<timeType, std::uint32_t>);
timeType constexpr maxTime = std::numeric_limits<timeType>::max();
static_assert(maxTime == 4'294'967'295);
auto const baseJson = [&]() {
auto createJson = env.json(
set(borrower, broker.brokerID, Number{55524'81, -2}),
fee(loanSetFee),
closePaymentFee(0),
gracePeriod(LoanSet::defaultGracePeriod),
interestRate(TenthBips32(12833)),
lateInterestRate(TenthBips32(77048)),
latePaymentFee(0),
loanOriginationFee(218),
json(sfCounterpartySignature, Json::objectValue));
createJson.removeMember(sfSequence.getJsonName());
return createJson;
}();
auto const baseFee = env.current()->fees().base;
auto parentCloseTime = [&]() {
return env.current()->parentCloseTime().time_since_epoch().count();
};
auto maxLoanTime = [&]() {
auto const startDate = parentCloseTime();
BEAST_EXPECT(startDate >= 50);
return maxTime - startDate;
};
{
// straight-up overflow: interval
auto const interval = maxLoanTime() + 1;
auto const total = 1;
auto createJson = env.json(baseJson, paymentInterval(interval), paymentTotal(total));
env(createJson, sig(sfCounterpartySignature, lender), ter(tecKILLED));
env.close();
}
{
// straight-up overflow: total
// min interval is 60
auto const interval = 60;
auto const total = maxLoanTime() + 1;
auto createJson = env.json(baseJson, paymentInterval(interval), paymentTotal(total));
env(createJson, sig(sfCounterpartySignature, lender), ter(tecKILLED));
env.close();
}
{
// straight-up overflow: grace period
// min interval is 60
auto const interval = maxLoanTime() + 1;
auto const total = 1;
auto const grace = interval;
auto createJson = env.json(
baseJson, paymentInterval(interval), paymentTotal(total), gracePeriod(grace));
// The grace period can't be larger than the interval.
env(createJson, sig(sfCounterpartySignature, lender), ter(tecKILLED));
env.close();
}
{
// Overflow with multiplication of a few large intervals
auto const interval = 1'000'000'000;
auto const total = 10;
auto createJson = env.json(baseJson, paymentInterval(interval), paymentTotal(total));
env(createJson, sig(sfCounterpartySignature, lender), ter(tecKILLED));
env.close();
}
{
// Overflow with multiplication of many small payments
// min interval is 60
auto const interval = 60;
auto const total = 1'000'000'000;
auto createJson = env.json(baseJson, paymentInterval(interval), paymentTotal(total));
env(createJson, sig(sfCounterpartySignature, lender), ter(tecKILLED));
env.close();
}
{
// Overflow with an absurdly large grace period
// min interval is 60
auto const total = 60;
auto const interval = (maxLoanTime() - total) / total;
auto const grace = interval;
auto createJson = env.json(
baseJson, paymentInterval(interval), paymentTotal(total), gracePeriod(grace));
env(createJson, sig(sfCounterpartySignature, lender), ter(tecKILLED));
env.close();
}
{
// Start date when the ledger is closed will be larger
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
auto const grace = 100;
auto const interval = maxLoanTime() - grace;
auto const total = 1;
auto createJson = env.json(
baseJson, paymentInterval(interval), paymentTotal(total), gracePeriod(grace));
env(createJson, sig(sfCounterpartySignature, lender), ter(tesSUCCESS));
env.close();
// The transaction is killed in the closed ledger
auto const meta = env.meta();
if (BEAST_EXPECT(meta))
{
BEAST_EXPECT(meta->at(sfTransactionResult) == tecKILLED);
}
// If the transaction had succeeded, the loan would exist
auto const loanSle = env.le(keylet);
// but it doesn't
BEAST_EXPECT(!loanSle);
}
{
// Start date when the ledger is closed will be larger
auto const brokerStateBefore = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSequence = brokerStateBefore->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
auto const closeStartDate = (parentCloseTime() / 10 + 1) * 10;
auto const grace = 5'000;
auto const interval = maxTime - closeStartDate - grace;
auto const total = 1;
auto createJson = env.json(
baseJson, paymentInterval(interval), paymentTotal(total), gracePeriod(grace));
env(createJson, sig(sfCounterpartySignature, lender), ter(tesSUCCESS));
env.close();
// The transaction succeeds in the closed ledger
auto const meta = env.meta();
if (BEAST_EXPECT(meta))
{
BEAST_EXPECT(meta->at(sfTransactionResult) == tesSUCCESS);
}
// This loan exists
auto const afterState = getCurrentState(env, broker, keylet);
BEAST_EXPECT(afterState.nextPaymentDate == maxTime - grace);
BEAST_EXPECT(afterState.previousPaymentDate == 0);
BEAST_EXPECT(afterState.paymentRemaining == 1);
}
{
// Ensure the borrower has funds to pay back the loan
env(pay(issuer, borrower, iouAsset(Number{1'055'524'81, -2})));
// Start date when the ledger is closed will be larger
auto const closeStartDate = (parentCloseTime() / 10 + 1) * 10;
auto const grace = 5'000;
auto const maxLoanTime = maxTime - closeStartDate - grace;
auto const total = [&]() {
if (maxLoanTime % 5 == 0)
return 5;
if (maxLoanTime % 3 == 0)
return 3;
if (maxLoanTime % 2 == 0)
return 2;
return 0;
}();
if (!BEAST_EXPECT(total != 0))
return;
auto const brokerState = env.le(keylet::loanbroker(broker.brokerID));
// Intentionally shadow the outer values
auto const loanSequence = brokerState->at(sfLoanSequence);
auto const keylet = keylet::loan(broker.brokerID, loanSequence);
auto const interval = maxLoanTime / total;
auto createJson = env.json(
baseJson, paymentInterval(interval), paymentTotal(total), gracePeriod(grace));
env(createJson, sig(sfCounterpartySignature, lender), ter(tesSUCCESS));
env.close();
// This loan exists
auto const beforeState = getCurrentState(env, broker, keylet);
BEAST_EXPECT(beforeState.nextPaymentDate == closeStartDate + interval);
BEAST_EXPECT(beforeState.previousPaymentDate == 0);
BEAST_EXPECT(beforeState.paymentRemaining == total);
BEAST_EXPECT(beforeState.periodicPayment > 0);
// pay all but the last payment
{
NumberRoundModeGuard mg{Number::upward};
Number const payment = beforeState.periodicPayment * (total - 1);
XRPAmount const payFee{baseFee * ((total - 1) / loanPaymentsPerFeeIncrement + 1)};
STAmount const paymentAmount =
roundToScale(STAmount{broker.asset, payment}, beforeState.loanScale);
auto loanPayTx = env.json(pay(borrower, keylet.key, paymentAmount), fee(payFee));
env(loanPayTx, ter(tesSUCCESS));
env.close();
}
// The loan is on the last payment
auto const afterState = getCurrentState(env, broker, keylet);
BEAST_EXPECT(afterState.paymentRemaining == 1);
BEAST_EXPECT(afterState.nextPaymentDate == maxTime - grace);
BEAST_EXPECT(afterState.previousPaymentDate == maxTime - grace - interval);
}
}
void
testRequireAuth()
{
testcase("Require Auth - Implicit Pseudo-account authorization");
using namespace jtx;
using namespace loan;
Account const lender{"lender"};
Account const issuer{"issuer"};
Account const borrower{"borrower"};
Env env(*this);
env.fund(XRP(100'000), issuer, lender, borrower);
env.close();
auto asset = MPTTester({
.env = env,
.issuer = issuer,
.holders = {lender, borrower},
.flags = MPTDEXFlags | tfMPTRequireAuth | tfMPTCanClawback | tfMPTCanLock,
.authHolder = true,
});
env(pay(issuer, lender, asset(5'000'000)));
BrokerInfo brokerInfo{createVaultAndBroker(env, asset, lender)};
auto const loanSetFee = fee(env.current()->fees().base * 2);
STAmount const debtMaximumRequest = brokerInfo.asset(1'000).value();
auto forUnauthAuth = [&](auto&& doTx) {
for (auto const flag : {tfMPTUnauthorize, 0u})
{
asset.authorize({.account = issuer, .holder = borrower, .flags = flag});
env.close();
doTx(flag == 0);
env.close();
}
};
// Can't create a loan if the borrower is not authorized
forUnauthAuth([&](bool authorized) {
auto const err = !authorized ? ter(tecNO_AUTH) : ter(tesSUCCESS);
env(set(borrower, brokerInfo.brokerID, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
err);
});
std::uint32_t constexpr loanSequence = 1;
auto const loanKeylet = keylet::loan(brokerInfo.brokerID, loanSequence);
// Can't loan pay if the borrower is not authorized
forUnauthAuth([&](bool authorized) {
auto const err = !authorized ? ter(tecNO_AUTH) : ter(tesSUCCESS);
env(pay(borrower, loanKeylet.key, debtMaximumRequest), err);
});
}
void
testCoverDepositWithdrawNonTransferableMPT()
{
testcase("CoverDeposit and CoverWithdraw reject MPT without CanTransfer");
using namespace jtx;
using namespace loanBroker;
Env env(*this, all);
Account const issuer{"issuer"};
Account const alice{"alice"};
env.fund(XRP(100'000), issuer, alice);
env.close();
MPTTester mpt{env, issuer, mptInitNoFund};
mpt.create({.flags = tfMPTCanTransfer, .mutableFlags = tmfMPTCanMutateCanTransfer});
env.close();
PrettyAsset const asset = mpt["MPT"];
mpt.authorize({.account = alice});
env.close();
// Issuer can fund the holder even if CanTransfer is not set.
env(pay(issuer, alice, asset(100)));
env.close();
Vault vault{env};
auto const [createTx, vaultKeylet] = vault.create({.owner = alice, .asset = asset});
env(createTx);
env.close();
auto const brokerKeylet = keylet::loanbroker(alice.id(), env.seq(alice));
env(set(alice, vaultKeylet.key));
env.close();
auto const brokerSle = env.le(brokerKeylet);
if (!BEAST_EXPECT(brokerSle))
return;
Account const pseudoAccount{"Loan Broker pseudo-account", brokerSle->at(sfAccount)};
// Remove CanTransfer after the broker is set up.
mpt.set({.mutableFlags = tmfMPTClearCanTransfer});
env.close();
// Standard Payment path should forbid third-party transfers.
env(pay(alice, pseudoAccount, asset(1)), ter(tecNO_AUTH));
env.close();
// Cover cannot be transferred to broker account
auto const depositAmount = asset(1);
env(coverDeposit(alice, brokerKeylet.key, depositAmount), ter{tecNO_AUTH});
env.close();
if (auto const refreshed = env.le(brokerKeylet); BEAST_EXPECT(refreshed))
{
BEAST_EXPECT(refreshed->at(sfCoverAvailable) == 0);
env.require(balance(pseudoAccount, asset(0)));
}
// Set CanTransfer again and transfer some deposit
mpt.set({.mutableFlags = tmfMPTSetCanTransfer});
env.close();
env(coverDeposit(alice, brokerKeylet.key, depositAmount));
env.close();
if (auto const refreshed = env.le(brokerKeylet); BEAST_EXPECT(refreshed))
{
BEAST_EXPECT(refreshed->at(sfCoverAvailable) == 1);
env.require(balance(pseudoAccount, depositAmount));
}
// Remove CanTransfer after the deposit
mpt.set({.mutableFlags = tmfMPTClearCanTransfer});
env.close();
// Cover cannot be transferred from broker account
env(coverWithdraw(alice, brokerKeylet.key, depositAmount), ter{tecNO_AUTH});
env.close();
// Set CanTransfer again and withdraw
mpt.set({.mutableFlags = tmfMPTSetCanTransfer});
env.close();
env(coverWithdraw(alice, brokerKeylet.key, depositAmount));
env.close();
if (auto const refreshed = env.le(brokerKeylet); BEAST_EXPECT(refreshed))
{
BEAST_EXPECT(refreshed->at(sfCoverAvailable) == 0);
env.require(balance(pseudoAccount, asset(0)));
}
}
#if LOAN_TODO
void
testLoanPayLateFullPaymentBypassesPenalties()
{
testcase("LoanPay full payment skips late penalties");
using namespace jtx;
using namespace loan;
using namespace std::chrono_literals;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000), issuer, lender, borrower);
env.close();
PrettyAsset const asset = issuer[iouCurrency];
env(trust(lender, asset(100'000'000)));
env(trust(borrower, asset(100'000'000)));
env(pay(issuer, lender, asset(50'000'000)));
env(pay(issuer, borrower, asset(5'000'000)));
env.close();
BrokerInfo broker{createVaultAndBroker(env, asset, lender)};
auto const loanSetFee = fee(env.current()->fees().base * 2);
auto const brokerPreLoan = env.le(keylet::loanbroker(broker.brokerID));
if (BEAST_EXPECT(brokerPreLoan); !brokerPreLoan.has_value())
return;
auto const loanSequence = brokerPreLoan->at(sfLoanSequence);
auto const loanKeylet = keylet::loan(broker.brokerID, loanSequence);
Number const principal = asset(1'000).value();
Number const serviceFee = asset(2).value();
Number const lateFee = asset(5).value();
Number const closeFee = asset(4).value();
env(set(borrower, broker.brokerID, principal),
sig(sfCounterpartySignature, lender),
loanServiceFee(serviceFee),
latePaymentFee(lateFee),
closePaymentFee(closeFee),
interestRate(percentageToTenthBips(12)),
lateInterestRate(percentageToTenthBips(24) / 10),
closeInterestRate(percentageToTenthBips(5)),
paymentTotal(12),
paymentInterval(600),
gracePeriod(0),
fee(loanSetFee));
env.close();
auto state1 = getCurrentState(env, broker, loanKeylet);
if (!BEAST_EXPECT(state1.paymentRemaining > 1))
return;
using d = NetClock::duration;
using tp = NetClock::time_point;
auto const overdueClose = tp{d{state1.nextPaymentDate + state1.paymentInterval}};
env.close(overdueClose);
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
auto const loanSle = env.le(loanKeylet);
if (!BEAST_EXPECT(brokerSle && loanSle))
return;
auto state = getCurrentState(env, broker, loanKeylet);
TenthBips16 const managementFeeRate{brokerSle->at(sfManagementFeeRate)};
TenthBips32 const interestRateValue{loanSle->at(sfInterestRate)};
TenthBips32 const lateInterestRateValue{loanSle->at(sfLateInterestRate)};
TenthBips32 const closeInterestRateValue{loanSle->at(sfCloseInterestRate)};
Number const closePaymentFeeRounded =
roundToAsset(broker.asset, loanSle->at(sfClosePaymentFee), state.loanScale);
Number const latePaymentFeeRounded =
roundToAsset(broker.asset, loanSle->at(sfLatePaymentFee), state.loanScale);
auto const roundedLoanState = constructLoanState(
state.totalValue, state.principalOutstanding, state.managementFeeOutstanding);
Number const totalInterestOutstanding = roundedLoanState.interestDue;
auto const periodicRate = loanPeriodicRate(interestRateValue, state.paymentInterval);
auto const rawLoanState = computeTheoreticalLoanState(
state.periodicPayment, periodicRate, state.paymentRemaining, managementFeeRate);
auto const parentCloseTime = env.current()->parentCloseTime();
auto const startDateSeconds =
static_cast<std::uint32_t>(state.startDate.time_since_epoch().count());
Number const fullPaymentInterest = computeFullPaymentInterest(
rawLoanState.principalOutstanding,
periodicRate,
parentCloseTime,
state.paymentInterval,
state.previousPaymentDate,
startDateSeconds,
closeInterestRateValue);
Number const roundedFullInterestAmount =
roundToAsset(broker.asset, fullPaymentInterest, state.loanScale);
Number const roundedFullManagementFee = computeManagementFee(
broker.asset, roundedFullInterestAmount, managementFeeRate, state.loanScale);
Number const roundedFullInterest = roundedFullInterestAmount - roundedFullManagementFee;
Number const trackedValueDelta =
state.principalOutstanding + totalInterestOutstanding + state.managementFeeOutstanding;
Number const untrackedManagementFee =
closePaymentFeeRounded + roundedFullManagementFee - state.managementFeeOutstanding;
Number const untrackedInterest = roundedFullInterest - totalInterestOutstanding;
Number const baseFullDue = trackedValueDelta + untrackedInterest + untrackedManagementFee;
BEAST_EXPECT(baseFullDue == roundToAsset(broker.asset, baseFullDue, state.loanScale));
auto const overdueSeconds =
parentCloseTime.time_since_epoch().count() - state.nextPaymentDate;
if (!BEAST_EXPECT(overdueSeconds > 0))
return;
Number const overdueRate = loanPeriodicRate(lateInterestRateValue, overdueSeconds);
Number const lateInterestRaw = state.principalOutstanding * overdueRate;
Number const lateInterestRounded =
roundToAsset(broker.asset, lateInterestRaw, state.loanScale);
Number const lateManagementFeeRounded = computeManagementFee(
broker.asset, lateInterestRounded, managementFeeRate, state.loanScale);
Number const penaltyDue =
lateInterestRounded + lateManagementFeeRounded + latePaymentFeeRounded;
BEAST_EXPECT(penaltyDue > Number{});
auto const balanceBefore = env.balance(borrower, broker.asset).number();
STAmount const paymentAmount{broker.asset.raw(), baseFullDue};
env(pay(borrower, loanKeylet.key, paymentAmount, tfLoanFullPayment));
env.close();
if (auto const meta = env.meta(); BEAST_EXPECT(meta))
BEAST_EXPECT(meta->at(sfTransactionResult) == tesSUCCESS);
auto const balanceAfter = env.balance(borrower, broker.asset).number();
Number const actualPaid = balanceBefore - balanceAfter;
BEAST_EXPECT(actualPaid == baseFullDue);
Number const expectedWithPenalty = baseFullDue + penaltyDue;
BEAST_EXPECT(expectedWithPenalty > actualPaid);
BEAST_EXPECT(expectedWithPenalty - actualPaid == penaltyDue);
}
void
testLoanCoverMinimumRoundingExploit()
{
auto testLoanCoverMinimumRoundingExploit = [&, this](Number const& principalRequest) {
testcase << "LoanBrokerCoverClawback drains cover via rounding"
<< " principalRequested=" << to_string(principalRequest);
using namespace jtx;
using namespace loan;
using namespace loanBroker;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(1'000'000'000), issuer, lender, borrower);
env.close();
env(fset(issuer, asfAllowTrustLineClawback));
env.close();
PrettyAsset const asset = issuer[iouCurrency];
env(trust(lender, asset(2'000'0000)));
env(trust(borrower, asset(2'000'0000)));
env.close();
env(pay(issuer, lender, asset(2'000'0000)));
env.close();
BrokerParameters brokerParams{.debtMax = 0, .coverRateMin = TenthBips32{10'000}};
BrokerInfo broker{createVaultAndBroker(env, asset, lender, brokerParams)};
auto const loanSetFee = fee(env.current()->fees().base * 2);
auto createTx = env.jt(
set(borrower, broker.brokerID, principalRequest),
sig(sfCounterpartySignature, lender),
loanSetFee,
paymentInterval(600),
paymentTotal(1),
gracePeriod(60));
env(createTx);
env.close();
auto const brokerBefore = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerBefore);
if (!brokerBefore)
return;
Number const debtOutstanding = brokerBefore->at(sfDebtTotal);
Number const coverAvailableBefore = brokerBefore->at(sfCoverAvailable);
BEAST_EXPECT(debtOutstanding > Number{});
BEAST_EXPECT(coverAvailableBefore > Number{});
log << "debt=" << to_string(debtOutstanding)
<< " cover_available=" << to_string(coverAvailableBefore);
env(coverClawback(issuer, 0), loanBrokerID(broker.brokerID));
env.close();
auto const brokerAfter = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerAfter);
if (!brokerAfter)
return;
Number const debtAfter = brokerAfter->at(sfDebtTotal);
// the debt has not changed
BEAST_EXPECT(debtAfter == debtOutstanding);
Number const coverAvailableAfter = brokerAfter->at(sfCoverAvailable);
// since the cover rate min != 0, the cover available should not
// be zero
BEAST_EXPECT(coverAvailableAfter != Number{});
};
// Call the lambda with different principal values
testLoanCoverMinimumRoundingExploit(Number{1, -30}); // 1e-30 units
testLoanCoverMinimumRoundingExploit(Number{1, -20}); // 1e-20 units
testLoanCoverMinimumRoundingExploit(Number{1, -10}); // 1e-10 units
testLoanCoverMinimumRoundingExploit(Number{1, 1}); // 1e-10 units
}
#endif
void
testPoC_UnsignedUnderflowOnFullPayAfterEarlyPeriodic()
{
// --- PoC Summary ----------------------------------------------------
// Scenario: Borrower makes one periodic payment early (before next due)
// so doPayment sets sfPreviousPaymentDueDate to the (future)
// sfNextPaymentDueDate and advances sfNextPaymentDueDate by one
// interval. Borrower then immediately performs a full-payment
// (tfLoanFullPayment). Why it matters: Full-payment interest accrual
// uses
// delta = now - max(prevPaymentDate, startDate)
// with an unsigned clock representation (uint32). If prevPaymentDate is
// in the future, the subtraction underflows to a very large positive
// number. This inflates roundedFullInterest and total full-close due,
// and LoanPay applies the inflated valueChange to the vault
// (sfAssetsTotal), increasing NAV.
// --------------------------------------------------------------------
testcase("PoC: Unsigned-underflow full-pay accrual after early periodic");
using namespace jtx;
using namespace loan;
using namespace std::chrono_literals;
Env env(*this, all);
Account const lender{"poc_lender4"};
Account const borrower{"poc_borrower4"};
env.fund(XRP(3'000'000), lender, borrower);
env.close();
PrettyAsset const asset{xrpIssue(), 1'000'000};
BrokerParameters brokerParams{};
auto const broker = createVaultAndBroker(env, asset, lender, brokerParams);
// Create a 3-payment loan so full-payment path is enabled after 1
// periodic payment.
auto const loanSetFee = fee(env.current()->fees().base * 2);
Number const principalRequest = asset(1000).value();
auto const originationFee = asset(0).value();
auto const serviceFee = asset(1).value();
auto const serviceFeePA = asset(1);
auto const lateFee = asset(0).value();
auto const closeFee = asset(0).value();
auto const interest = percentageToTenthBips(12);
auto const lateInterest = percentageToTenthBips(12) / 10;
auto const closeInterest = percentageToTenthBips(12) / 10;
auto const overpaymentInterest = percentageToTenthBips(12) / 10;
auto const total = 3u;
auto const interval = 600u;
auto const grace = 60u;
auto createJtx = env.jt(
set(borrower, broker.brokerID, principalRequest, 0),
sig(sfCounterpartySignature, lender),
loanOriginationFee(originationFee),
loanServiceFee(serviceFee),
latePaymentFee(lateFee),
closePaymentFee(closeFee),
overpaymentFee(percentageToTenthBips(5) / 10),
interestRate(interest),
lateInterestRate(lateInterest),
closeInterestRate(closeInterest),
overpaymentInterestRate(overpaymentInterest),
paymentTotal(total),
paymentInterval(interval),
gracePeriod(grace),
fee(loanSetFee));
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle);
auto const loanSequence = brokerSle ? brokerSle->at(sfLoanSequence) : 0;
auto const loanKeylet = keylet::loan(broker.brokerID, loanSequence);
env(createJtx);
env.close();
// Compute a regular periodic due and pay it early (before next due).
auto state = getCurrentState(env, broker, loanKeylet);
Number const periodicRate = loanPeriodicRate(state.interestRate, state.paymentInterval);
auto const components = detail::computePaymentComponents(
asset.raw(),
state.loanScale,
state.totalValue,
state.principalOutstanding,
state.managementFeeOutstanding,
state.periodicPayment,
periodicRate,
state.paymentRemaining,
brokerParams.managementFeeRate);
STAmount const regularDue{asset, components.trackedValueDelta + serviceFeePA.number()};
// now < nextDue immediately after creation, so this is an early pay.
env(pay(borrower, loanKeylet.key, regularDue));
env.close();
// Immediately attempt a full payoff. Compute the exact full-payment
// due to ensure the tx applies.
auto after = getCurrentState(env, broker, loanKeylet);
auto const loanSle = env.le(loanKeylet);
BEAST_EXPECT(loanSle);
auto const brokerSle2 = env.le(keylet::loanbroker(broker.brokerID));
BEAST_EXPECT(brokerSle2);
auto const closePaymentFee = loanSle ? loanSle->at(sfClosePaymentFee) : Number{};
auto const closeInterestRate =
loanSle ? TenthBips32{loanSle->at(sfCloseInterestRate)} : TenthBips32{};
auto const managementFeeRate =
brokerSle2 ? TenthBips16{brokerSle2->at(sfManagementFeeRate)} : TenthBips16{};
Number const periodicRate2 = loanPeriodicRate(after.interestRate, after.paymentInterval);
// Accrued + prepayment-penalty interest based on current periodic
// schedule
auto const fullPaymentInterest = computeFullPaymentInterest(
detail::loanPrincipalFromPeriodicPayment(
after.periodicPayment, periodicRate2, after.paymentRemaining),
periodicRate2,
env.current()->parentCloseTime(),
after.paymentInterval,
after.previousPaymentDate,
static_cast<std::uint32_t>(after.startDate.time_since_epoch().count()),
closeInterestRate);
// Round to asset scale and split interest/fee parts
auto const roundedInterest =
roundToAsset(asset.raw(), fullPaymentInterest, after.loanScale);
Number const roundedFullMgmtFee =
computeManagementFee(asset.raw(), roundedInterest, managementFeeRate, after.loanScale);
Number const roundedFullInterest = roundedInterest - roundedFullMgmtFee;
// Show both signed and unsigned deltas to highlight the underflow.
auto const nowSecs =
static_cast<std::uint32_t>(env.current()->parentCloseTime().time_since_epoch().count());
auto const startSecs =
static_cast<std::uint32_t>(after.startDate.time_since_epoch().count());
auto const lastPaymentDate = std::max(after.previousPaymentDate, startSecs);
auto const signedDelta =
static_cast<std::int64_t>(nowSecs) - static_cast<std::int64_t>(lastPaymentDate);
auto const unsignedDelta = static_cast<std::uint32_t>(nowSecs - lastPaymentDate);
log << "PoC window: prev=" << after.previousPaymentDate << " start=" << startSecs
<< " now=" << nowSecs << " signedDelta=" << signedDelta
<< " unsignedDelta=" << unsignedDelta << std::endl;
// Reference (clamped) computation: emulate a non-negative accrual
// window by clamping prevPaymentDate to 'now' for the full-pay path.
auto const prevClamped = std::min(after.previousPaymentDate, nowSecs);
auto const fullPaymentInterestClamped = computeFullPaymentInterest(
detail::loanPrincipalFromPeriodicPayment(
after.periodicPayment, periodicRate2, after.paymentRemaining),
periodicRate2,
env.current()->parentCloseTime(),
after.paymentInterval,
prevClamped,
startSecs,
closeInterestRate);
auto const roundedInterestClamped =
roundToAsset(asset.raw(), fullPaymentInterestClamped, after.loanScale);
Number const roundedFullMgmtFeeClamped = computeManagementFee(
asset.raw(), roundedInterestClamped, managementFeeRate, after.loanScale);
Number const roundedFullInterestClamped =
roundedInterestClamped - roundedFullMgmtFeeClamped;
STAmount const fullDueClamped{
asset,
after.principalOutstanding + roundedFullInterestClamped + roundedFullMgmtFeeClamped +
closePaymentFee};
// Collect vault NAV before closing payment
auto const vaultId2 = brokerSle2 ? brokerSle2->at(sfVaultID) : uint256{};
auto const vaultKey2 = keylet::vault(vaultId2);
auto const vaultBefore = env.le(vaultKey2);
BEAST_EXPECT(vaultBefore);
Number const assetsTotalBefore = vaultBefore ? vaultBefore->at(sfAssetsTotal) : Number{};
STAmount const fullDue{
asset,
after.principalOutstanding + roundedFullInterest + roundedFullMgmtFee +
closePaymentFee};
log << "PoC payoff: principalOutstanding=" << after.principalOutstanding
<< " roundedFullInterest=" << roundedFullInterest
<< " roundedFullMgmtFee=" << roundedFullMgmtFee << " closeFee=" << closePaymentFee
<< " fullDue=" << to_string(fullDue.getJson()) << std::endl;
log << "PoC reference (clamped): roundedFullInterestClamped=" << roundedFullInterestClamped
<< " roundedFullMgmtFeeClamped=" << roundedFullMgmtFeeClamped
<< " fullDueClamped=" << to_string(fullDueClamped.getJson()) << std::endl;
env(pay(borrower, loanKeylet.key, fullDue), txflags(tfLoanFullPayment));
env.close();
// Sanity: underflow present (unsigned delta very large relative to
// interval)
BEAST_EXPECT(unsignedDelta > after.paymentInterval);
// Compare vault NAV before/after the full close
auto const vaultAfter = env.le(vaultKey2);
BEAST_EXPECT(vaultAfter);
if (vaultAfter)
{
auto const assetsTotalAfter = vaultAfter->at(sfAssetsTotal);
log << "PoC NAV: assetsTotalBefore=" << assetsTotalBefore
<< " assetsTotalAfter=" << assetsTotalAfter
<< " delta=" << (assetsTotalAfter - assetsTotalBefore) << std::endl;
// Value-based proof: underflowed window yields a payoff larger than
// the clamped (non-underflow) reference.
BEAST_EXPECT(fullDue == fullDueClamped);
if (fullDue > fullDueClamped)
log << "PoC delta: overcharge (fullDue > clamped)" << std::endl;
}
// Loan should be paid off
auto const finalLoan = env.le(loanKeylet);
BEAST_EXPECT(finalLoan);
if (finalLoan)
{
BEAST_EXPECT(finalLoan->at(sfPaymentRemaining) == 0);
BEAST_EXPECT(finalLoan->at(sfPrincipalOutstanding) == 0);
}
}
void
testDustManipulation()
{
testcase("Dust manipulation");
using namespace jtx;
using namespace std::chrono_literals;
Env env(*this, all);
// Setup: Create accounts
Account issuer{"issuer"};
Account lender{"lender"};
Account borrower{"borrower"};
Account victim{"victim"};
env.fund(XRP(1'000'000'00), issuer, lender, borrower, victim);
env.close();
// Step 1: Create vault with IOU asset
auto asset = issuer["USD"];
env(trust(lender, asset(100000)));
env(trust(borrower, asset(100000)));
env(trust(victim, asset(100000)));
env(pay(issuer, lender, asset(50000)));
env(pay(issuer, borrower, asset(50000)));
env(pay(issuer, victim, asset(50000)));
env.close();
BrokerParameters brokerParams{
.vaultDeposit = 10000,
.debtMax = Number{0},
.coverRateMin = TenthBips32{1000},
.coverRateLiquidation = TenthBips32{2500}};
auto broker = createVaultAndBroker(env, asset, lender, brokerParams);
auto const loanKeyletOpt = [&]() -> std::optional<Keylet> {
auto const brokerSle = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(brokerSle))
return std::nullopt;
// Broker has no loans
BEAST_EXPECT(brokerSle->at(sfOwnerCount) == 0);
// The loan keylet is based on the LoanSequence of the
// _LOAN_BROKER_ object.
auto const loanSequence = brokerSle->at(sfLoanSequence);
return keylet::loan(broker.brokerID, loanSequence);
}();
if (!loanKeyletOpt)
return;
auto const& vaultKeylet = broker.vaultKeylet();
{
auto const vaultSle = env.le(vaultKeylet);
Number assetsTotal = vaultSle->at(sfAssetsTotal);
Number assetsAvail = vaultSle->at(sfAssetsAvailable);
log << "Before loan creation:" << std::endl;
log << " AssetsTotal: " << assetsTotal << std::endl;
log << " AssetsAvailable: " << assetsAvail << std::endl;
log << " Difference: " << (assetsTotal - assetsAvail) << std::endl;
// before the loan the assets total and available should be equal
BEAST_EXPECT(assetsAvail == assetsTotal);
BEAST_EXPECT(assetsAvail == broker.asset(brokerParams.vaultDeposit).number());
}
Keylet const& loanKeylet = *loanKeyletOpt;
LoanParameters const loanParams{
.account = lender,
.counter = borrower,
.principalRequest = Number{100},
.interest = TenthBips32{1922},
.payTotal = 5816,
.payInterval = 86400 * 6,
.gracePd = 86400 * 5,
};
env(loanParams(env, broker));
env.close();
// Wait for loan to be late enough to default
env.close(std::chrono::seconds(86400 * 40)); // 40 days
{
auto const vaultSle = env.le(vaultKeylet);
Number assetsTotal = vaultSle->at(sfAssetsTotal);
Number assetsAvail = vaultSle->at(sfAssetsAvailable);
log << "After loan creation:" << std::endl;
log << " AssetsTotal: " << assetsTotal << std::endl;
log << " AssetsAvailable: " << assetsAvail << std::endl;
log << " Difference: " << (assetsTotal - assetsAvail) << std::endl;
auto const loanSle = env.le(loanKeylet);
if (!BEAST_EXPECT(loanSle))
return;
auto const state = constructRoundedLoanState(loanSle);
log << "Loan state:" << std::endl;
log << " ValueOutstanding: " << state.valueOutstanding << std::endl;
log << " PrincipalOutstanding: " << state.principalOutstanding << std::endl;
log << " InterestOutstanding: " << state.interestOutstanding() << std::endl;
log << " InterestDue: " << state.interestDue << std::endl;
log << " FeeDue: " << state.managementFeeDue << std::endl;
// after loan creation the assets total and available should
// reflect the value of the loan
BEAST_EXPECT(assetsAvail < assetsTotal);
BEAST_EXPECT(
assetsAvail ==
broker.asset(brokerParams.vaultDeposit - loanParams.principalRequest).number());
BEAST_EXPECT(
assetsTotal ==
broker.asset(brokerParams.vaultDeposit + state.interestDue).number());
}
// Step 7: Trigger default (dust adjustment will occur)
env(jtx::loan::manage(lender, loanKeylet.key, tfLoanDefault));
env.close();
// Step 8: Verify phantom assets created
{
auto const vaultSle2 = env.le(vaultKeylet);
Number assetsTotal2 = vaultSle2->at(sfAssetsTotal);
Number assetsAvail2 = vaultSle2->at(sfAssetsAvailable);
log << "After default:" << std::endl;
log << " AssetsTotal: " << assetsTotal2 << std::endl;
log << " AssetsAvailable: " << assetsAvail2 << std::endl;
log << " Difference: " << (assetsTotal2 - assetsAvail2) << std::endl;
// after a default the assets total and available should be equal
BEAST_EXPECT(assetsAvail2 == assetsTotal2);
}
}
void
testRIPD3831()
{
using namespace jtx;
testcase("RIPD-3831");
Account const issuer("issuer");
Account const lender("lender");
Account const borrower("borrower");
BrokerParameters const brokerParams{
.vaultDeposit = 100000,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
// .managementFeeRate = TenthBips16{5919},
.coverRateLiquidation = TenthBips32{0}};
LoanParameters const loanParams{
.account = lender,
.counter = borrower,
.principalRequest = Number{200'000, -6},
.lateFee = Number{200, -6},
.interest = TenthBips32{50'000},
.payTotal = 10,
.payInterval = 150};
auto const assetType = AssetType::XRP;
Env env(*this, all);
auto loanResult =
createLoan(env, assetType, brokerParams, loanParams, issuer, lender, borrower);
if (BEAST_EXPECT(loanResult); !loanResult.has_value())
return;
auto broker = std::get<BrokerInfo>(*loanResult);
auto loanKeylet = std::get<Keylet>(*loanResult);
using tp = NetClock::time_point;
using d = NetClock::duration;
auto state = getCurrentState(env, broker, loanKeylet);
if (auto loan = env.le(loanKeylet); BEAST_EXPECT(loan))
{
env.close(tp{d{loan->at(sfNextPaymentDueDate) + loan->at(sfGracePeriod) + 1}});
}
topUpBorrower(env, broker, issuer, borrower, state, loanParams.serviceFee);
using namespace jtx::loan;
auto jv = pay(borrower, loanKeylet.key, drops(XRPAmount(state.totalValue)));
{
auto const submitParam = to_string(jv);
auto const jr = env.rpc("submit", borrower.name(), submitParam);
BEAST_EXPECT(jr.isMember(jss::result));
auto const jResult = jr[jss::result];
}
env.close();
// Make sure the system keeps responding
env(noop(borrower));
env.close();
env(noop(issuer));
env.close();
env(noop(lender));
env.close();
}
void
testRIPD3459()
{
testcase("RIPD-3459 - LoanBroker incorrect debt total");
using namespace jtx;
Account const issuer("issuer");
Account const lender("lender");
Account const borrower("borrower");
BrokerParameters const brokerParams{
.vaultDeposit = 200'000,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
.managementFeeRate = TenthBips16{500},
.coverRateLiquidation = TenthBips32{0}};
LoanParameters const loanParams{
.account = lender,
.counter = borrower,
.principalRequest = Number{100'000, -4},
.interest = TenthBips32{100'000},
.payTotal = 10};
auto const assetType = AssetType::MPT;
Env env(*this, all);
auto loanResult =
createLoan(env, assetType, brokerParams, loanParams, issuer, lender, borrower);
if (BEAST_EXPECT(loanResult); !loanResult.has_value())
return;
auto broker = std::get<BrokerInfo>(*loanResult);
auto loanKeylet = std::get<Keylet>(*loanResult);
auto pseudoAcct = std::get<Account>(*loanResult);
VerifyLoanStatus verifyLoanStatus(env, broker, pseudoAcct, loanKeylet);
if (auto const brokerSle = env.le(broker.brokerKeylet()); BEAST_EXPECT(brokerSle))
{
if (auto const loanSle = env.le(loanKeylet); BEAST_EXPECT(loanSle))
{
BEAST_EXPECT(brokerSle->at(sfDebtTotal) == loanSle->at(sfTotalValueOutstanding));
}
}
makeLoanPayments(
env,
broker,
loanParams,
loanKeylet,
verifyLoanStatus,
issuer,
lender,
borrower,
PaymentParameters{.showStepBalances = true});
if (auto const brokerSle = env.le(broker.brokerKeylet()); BEAST_EXPECT(brokerSle))
{
if (auto const loanSle = env.le(loanKeylet); BEAST_EXPECT(loanSle))
{
BEAST_EXPECT(brokerSle->at(sfDebtTotal) == loanSle->at(sfTotalValueOutstanding));
BEAST_EXPECT(brokerSle->at(sfDebtTotal) == beast::zero);
}
}
}
void
testRIPD3901()
{
testcase("Crash with tfLoanOverpayment");
using namespace jtx;
using namespace loan;
Account const lender{"lender"};
Account const issuer{"issuer"};
Account const borrower{"borrower"};
Account const depositor{"depositor"};
auto const txfee = fee(XRP(100));
Env env(*this);
Vault vault(env);
env.fund(XRP(10'000), lender, issuer, borrower, depositor);
env.close();
auto [tx, vaultKeyLet] = vault.create({.owner = lender, .asset = xrpIssue()});
env(tx, txfee);
env.close();
env(vault.deposit({.depositor = depositor, .id = vaultKeyLet.key, .amount = XRP(1'000)}),
txfee);
env.close();
auto const brokerKeyLet = keylet::loanbroker(lender.id(), env.seq(lender));
env(loanBroker::set(lender, vaultKeyLet.key), txfee);
env.close();
// BrokerInfo brokerInfo{xrpIssue(), keylet, vaultKeyLet, {}};
STAmount const debtMaximumRequest = XRPAmount(200'000);
env(set(borrower, brokerKeyLet.key, debtMaximumRequest),
sig(sfCounterpartySignature, lender),
interestRate(TenthBips32(50'000)),
paymentTotal(2),
paymentInterval(150),
txflags(tfLoanOverpayment),
txfee);
env.close();
std::uint32_t const loanSequence = 1;
auto const loanKeylet = keylet::loan(brokerKeyLet.key, loanSequence);
if (auto loan = env.le(loanKeylet); env.test.BEAST_EXPECT(loan))
{
env(loan::pay(borrower, loanKeylet.key, XRPAmount(150'001)),
txflags(tfLoanOverpayment),
txfee);
env.close();
}
}
void
testRoundingAllowsUndercoverage()
{
testcase("Minimum cover rounding allows undercoverage (XRP)");
using namespace jtx;
using namespace loanBroker;
Env env(*this, all);
Account const lender{"lender"};
Account const borrower{"borrower"};
env.fund(XRP(200'000), lender, borrower);
env.close();
// Vault with XRP asset
Vault vault{env};
auto [vaultCreate, vaultKeylet] = vault.create({.owner = lender, .asset = xrpIssue()});
env(vaultCreate);
env.close();
BEAST_EXPECT(env.le(vaultKeylet));
// Seed the vault with XRP so it can fund the loan principal
PrettyAsset const xrpAsset{xrpIssue(), 1};
BrokerParameters const brokerParams{
.vaultDeposit = 1'000,
.debtMax = Number{0},
.coverRateMin = TenthBips32{10'000},
.coverDeposit = 82,
};
auto const brokerInfo = createVaultAndBroker(env, xrpAsset, lender, brokerParams);
// Create a loan with principal 804 XRP and 0% interest (so
// DebtTotal increases by exactly 804)
env(loan::set(borrower, brokerInfo.brokerID, xrpAsset(804).value()),
loan::interestRate(TenthBips32(0)),
sig(sfCounterpartySignature, lender),
fee(env.current()->fees().base * 2));
BEAST_EXPECT(env.ter() == tesSUCCESS);
env.close();
// Verify DebtTotal is exactly 804
if (auto const brokerSle = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(brokerSle))
{
log << *brokerSle << std::endl;
BEAST_EXPECT(brokerSle->at(sfDebtTotal) == Number(804));
}
// Attempt to withdraw 2 XRP to self, leaving 80 XRP CoverAvailable.
// The minimum is 80.4 XRP, which rounds up to 81 XRP, so this fails.
env(coverWithdraw(lender, brokerInfo.brokerID, xrpAsset(2).value()),
ter(tecINSUFFICIENT_FUNDS));
BEAST_EXPECT(env.ter() == tecINSUFFICIENT_FUNDS);
env.close();
// Attempt to withdraw 1 XRP to self, leaving 81 XRP CoverAvailable.
// because that leaves sufficient cover, this succeeds
env(coverWithdraw(lender, brokerInfo.brokerID, xrpAsset(1).value()));
BEAST_EXPECT(env.ter() == tesSUCCESS);
env.close();
// Validate CoverAvailable == 80 XRP and DebtTotal remains 804
if (auto const brokerSle = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(brokerSle))
{
log << *brokerSle << std::endl;
BEAST_EXPECT(brokerSle->at(sfCoverAvailable) == xrpAsset(81).value());
BEAST_EXPECT(brokerSle->at(sfDebtTotal) == Number(804));
// Also demonstrate that the true minimum (804 * 10%) exceeds 80
auto const theoreticalMin = tenthBipsOfValue(Number(804), TenthBips32(10'000));
log << "Theoretical min cover: " << theoreticalMin << std::endl;
BEAST_EXPECT(Number(804, -1) == theoreticalMin);
}
}
void
testRIPD3902()
{
testcase("RIPD-3902 - 1 IOU loan payments");
using namespace jtx;
Account const issuer("issuer");
Account const lender("lender");
Account const borrower("borrower");
BrokerParameters const brokerParams{
.vaultDeposit = 10,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
.managementFeeRate = TenthBips16{0},
.coverRateLiquidation = TenthBips32{0}};
LoanParameters const loanParams{
.account = lender,
.counter = borrower,
.principalRequest = Number{1, 0},
.interest = TenthBips32{100'000},
.payTotal = 5,
.payInterval = 150,
.gracePd = 60};
auto const assetType = AssetType::IOU;
Env env(*this, all);
auto loanResult =
createLoan(env, assetType, brokerParams, loanParams, issuer, lender, borrower);
if (BEAST_EXPECT(loanResult); !loanResult.has_value())
return;
auto broker = std::get<BrokerInfo>(*loanResult);
auto loanKeylet = std::get<Keylet>(*loanResult);
auto pseudoAcct = std::get<Account>(*loanResult);
VerifyLoanStatus verifyLoanStatus(env, broker, pseudoAcct, loanKeylet);
makeLoanPayments(
env,
broker,
loanParams,
loanKeylet,
verifyLoanStatus,
issuer,
lender,
borrower,
PaymentParameters{.showStepBalances = true});
}
void
testBorrowerIsBroker()
{
testcase("Test Borrower is Broker");
using namespace jtx;
using namespace loan;
Account const broker{"broker"};
Account const issuer{"issuer"};
Account const borrower_{"borrower"};
Account const depositor{"depositor"};
auto testLoanAsset = [&](auto&& getMaxDebt, auto const& borrower) {
Env env(*this);
Vault vault(env);
if (borrower == broker)
{
env.fund(XRP(10'000), broker, issuer, depositor);
}
else
{
env.fund(XRP(10'000), broker, borrower, issuer, depositor);
}
env.close();
auto const xrpFee = XRP(100);
auto const txFee = fee(xrpFee);
STAmount const debtMaximumRequest = getMaxDebt(env);
auto const& asset = debtMaximumRequest.asset();
auto const initialVault = asset(debtMaximumRequest * 100);
auto [tx, vaultKeylet] = vault.create({.owner = broker, .asset = asset});
env(tx, txFee);
env.close();
env(vault.deposit(
{.depositor = depositor, .id = vaultKeylet.key, .amount = initialVault}),
txFee);
env.close();
auto const brokerKeylet = keylet::loanbroker(broker.id(), env.seq(broker));
env(loanBroker::set(broker, vaultKeylet.key), txFee);
env.close();
auto const serviceFee = 101;
env(set(broker, brokerKeylet.key, debtMaximumRequest),
counterparty(borrower),
sig(sfCounterpartySignature, borrower),
loanServiceFee(serviceFee),
paymentTotal(10),
txFee);
env.close();
std::uint32_t const loanSequence = 1;
auto const loanKeylet = keylet::loan(brokerKeylet.key, loanSequence);
auto const brokerBalanceBefore = env.balance(broker, asset);
if (auto const loanSle = env.le(loanKeylet); env.test.BEAST_EXPECT(loanSle))
{
auto const payment = loanSle->at(sfPeriodicPayment);
auto const totalPayment = payment + serviceFee;
env(loan::pay(borrower, loanKeylet.key, asset(totalPayment)), txFee);
env.close();
if (auto const vaultSle = env.le(vaultKeylet); BEAST_EXPECT(vaultSle))
{
auto const expected = [&]() {
// The service fee is transferred to the broker if
// a borrower is not the broker
if (borrower != broker)
return brokerBalanceBefore.number() + serviceFee;
// Since a borrower is the broker, the payment is
// transferred to the Vault from the broker but not
// the service fee.
// If the asset is XRP then the broker pays the txfee.
if (asset.native())
return brokerBalanceBefore.number() - payment - xrpFee.number();
return brokerBalanceBefore.number() - payment;
}();
BEAST_EXPECT(env.balance(broker, asset).value() == asset(expected).value());
}
}
};
// Test when a borrower is the broker and is not to verify correct
// service fee transfer in both cases.
for (auto const& borrowerAcct : {broker, borrower_})
{
testLoanAsset(
[&](Env&) -> STAmount { return STAmount{XRPAmount{200'000}}; }, borrowerAcct);
testLoanAsset(
[&](Env& env) -> STAmount {
auto const IOU = issuer["USD"];
env(trust(broker, IOU(1'000'000'000)));
env(trust(depositor, IOU(1'000'000'000)));
env(pay(issuer, broker, IOU(100'000'000)));
env(pay(issuer, depositor, IOU(100'000'000)));
env.close();
return IOU(200'000);
},
borrowerAcct);
testLoanAsset(
[&](Env& env) -> STAmount {
MPTTester mpt(
{.env = env,
.issuer = issuer,
.holders = {broker, depositor},
.pay = 100'000'000});
return mpt(200'000);
},
borrowerAcct);
}
}
void
testIssuerIsBorrower()
{
testcase("RIPD-4096 - Issuer as borrower");
using namespace jtx;
Account const issuer("issuer");
Account const lender("lender");
BrokerParameters const brokerParams{
.vaultDeposit = 100'000,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
.managementFeeRate = TenthBips16{0},
.coverRateLiquidation = TenthBips32{0}};
LoanParameters const loanParams{
.account = lender, .counter = issuer, .principalRequest = Number{10000}};
auto const assetType = AssetType::IOU;
Env env(*this, all);
auto loanResult =
createLoan(env, assetType, brokerParams, loanParams, issuer, lender, issuer);
if (BEAST_EXPECT(loanResult); !loanResult.has_value())
return;
auto broker = std::get<BrokerInfo>(*loanResult);
auto loanKeylet = std::get<Keylet>(*loanResult);
auto pseudoAcct = std::get<Account>(*loanResult);
VerifyLoanStatus verifyLoanStatus(env, broker, pseudoAcct, loanKeylet);
makeLoanPayments(
env,
broker,
loanParams,
loanKeylet,
verifyLoanStatus,
issuer,
lender,
issuer,
PaymentParameters{.showStepBalances = true});
}
void
testLimitExceeded()
{
testcase("RIPD-4125 - overpayment");
using namespace jtx;
Account const issuer("issuer");
Account const lender("lender");
Account const borrower("borrower");
BrokerParameters const brokerParams{
.vaultDeposit = 100'000,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
.managementFeeRate = TenthBips16{0},
.coverRateLiquidation = TenthBips32{0}};
LoanParameters const loanParams{
.account = lender,
.counter = borrower,
.principalRequest = Number{200000, -6},
.interest = TenthBips32{50000},
.payTotal = 3,
.payInterval = 200,
.gracePd = 60,
.flags = tfLoanOverpayment,
};
auto const assetType = AssetType::XRP;
Env env(*this, makeConfig(), all, nullptr, beast::severities::Severity::kWarning);
auto loanResult =
createLoan(env, assetType, brokerParams, loanParams, issuer, lender, borrower);
if (BEAST_EXPECT(loanResult); !loanResult.has_value())
return;
auto broker = std::get<BrokerInfo>(*loanResult);
auto loanKeylet = std::get<Keylet>(*loanResult);
auto pseudoAcct = std::get<Account>(*loanResult);
VerifyLoanStatus verifyLoanStatus(env, broker, pseudoAcct, loanKeylet);
auto const state = getCurrentState(env, broker, loanKeylet);
env(loan::pay(
borrower,
loanKeylet.key,
STAmount{broker.asset, state.periodicPayment * 3 / 2 + 1},
tfLoanOverpayment));
env.close();
PaymentParameters paymentParams{
.showStepBalances = false,
.validateBalances = true,
};
makeLoanPayments(
env,
broker,
loanParams,
loanKeylet,
verifyLoanStatus,
issuer,
lender,
borrower,
paymentParams);
}
void
testOverpaymentManagementFee()
{
testcase("testOverpaymentManagementFee");
using namespace jtx;
using namespace loan;
Env env(*this, all);
Account const lender{"lender"}, borrower{"borrower"};
env.fund(XRP(10'000'000), lender, borrower);
env.close();
PrettyAsset const asset{xrpIssue(), 1000};
auto const result = createVaultAndBroker(
env,
asset,
lender,
{
.vaultDeposit = asset(100'000).value(),
.managementFeeRate = TenthBips16(10'000),
});
auto const loanSetFee = fee(env.current()->fees().base * 2);
auto const loanKeylet = keylet::loan(
result.brokerKeylet().key, (env.le(result.brokerKeylet()))->at(sfLoanSequence));
env(loan::set(
borrower, result.brokerKeylet().key, asset(10'000).value(), tfLoanOverpayment),
sig(sfCounterpartySignature, lender),
loan::paymentInterval(86400 * 30),
loan::paymentTotal(3),
loan::overpaymentInterestRate(TenthBips32(percentageToTenthBips(20))),
loanSetFee);
// From calculator
auto const expectedOverpaymentManagementFee = Number{33333, 0};
auto const loanBrokerBalanceBefore = env.balance(lender);
auto const loanPayFee = fee(env.current()->fees().base * 2);
env(pay(borrower, loanKeylet.key, asset(5'000).value(), tfLoanOverpayment), loanPayFee);
env.close();
BEAST_EXPECTS(
env.balance(lender) - loanBrokerBalanceBefore == expectedOverpaymentManagementFee,
"overpayment management fee missmatch; expected:" +
to_string(expectedOverpaymentManagementFee) +
" got: " + to_string(env.balance(lender) - loanBrokerBalanceBefore));
}
void
testLoanPayBrokerOwnerMissingTrustline()
{
testcase << "LoanPay Broker Owner Missing Trustline (PoC)";
using namespace jtx;
using namespace loan;
Account const issuer("issuer");
Account const borrower("borrower");
Account const broker("broker");
auto const IOU = issuer["IOU"];
Env env(*this, all);
env.fund(XRP(20'000), issuer, broker, borrower);
env.close();
// Set up trustlines and fund accounts
env(trust(broker, IOU(20'000'000)));
env(trust(borrower, IOU(20'000'000)));
env(pay(issuer, broker, IOU(10'000'000)));
env(pay(issuer, borrower, IOU(1'000)));
env.close();
// Create vault and broker
auto const brokerInfo = createVaultAndBroker(env, IOU, broker);
// Create a loan first (this creates debt)
auto const keylet = keylet::loan(brokerInfo.brokerID, 1);
env(set(borrower, brokerInfo.brokerID, 10'000),
sig(sfCounterpartySignature, broker),
loanServiceFee(IOU(100).value()),
paymentInterval(100),
fee(XRP(100)));
env.close();
// Ensure broker has sufficient cover so brokerPayee == brokerOwner
// We need coverAvailable >= (debtTotal * coverRateMinimum)
// Deposit enough cover to ensure the fee goes to broker owner
// The default coverRateMinimum is 10%, so for a 10,000 loan we need
// at least 1,000 cover. Default cover is 1,000, so we add more to be
// safe.
auto const additionalCover = IOU(50'000).value();
env(loanBroker::coverDeposit(broker, brokerInfo.brokerID, STAmount{IOU, additionalCover}));
env.close();
// Verify broker owner has a trustline
auto const brokerTrustline = keylet::line(broker, IOU);
BEAST_EXPECT(env.le(brokerTrustline) != nullptr);
// Broker owner deletes their trustline
// First, pay any positive balance to issuer to zero it out
auto const brokerBalance = env.balance(broker, IOU);
env(pay(broker, issuer, brokerBalance));
env.close();
// Remove the trustline by setting limit to 0
env(trust(broker, IOU(0)));
env.close();
// Verify trustline is deleted
BEAST_EXPECT(env.le(brokerTrustline) == nullptr);
// Now borrower tries to make a payment
// We should get a tesSUCCESS instead of a tecNO_LINE.
env(pay(borrower, keylet.key, IOU(10'100)), fee(XRP(100)), ter(tesSUCCESS));
env.close();
// Verify trustline is still deleted
BEAST_EXPECT(env.le(brokerTrustline) == nullptr);
// Verify the service fee went to the broker pseudo-account
if (auto const brokerSle = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(brokerSle))
{
Account const pseudo("pseudo-account", brokerSle->at(sfAccount));
auto const balance = env.balance(pseudo, IOU);
// 1,000 default + 50,000 extra + 100 service fee from LoanPay
BEAST_EXPECTS(balance == IOU(51'100), to_string(Json::Value(balance)));
}
}
void
testLoanPayBrokerOwnerUnauthorizedMPT()
{
testcase << "LoanPay Broker Owner MPT unauthorized";
using namespace jtx;
using namespace loan;
Account const issuer("issuer");
Account const borrower("borrower");
Account const broker("broker");
Env env(*this, all);
env.fund(XRP(20'000), issuer, broker, borrower);
env.close();
MPTTester mptt{env, issuer, mptInitNoFund};
mptt.create({.flags = tfMPTCanClawback | tfMPTCanTransfer | tfMPTCanLock});
PrettyAsset const MPT{mptt.issuanceID()};
// Authorize broker and borrower
mptt.authorize({.account = broker});
mptt.authorize({.account = borrower});
env.close();
// Fund accounts
env(pay(issuer, broker, MPT(10'000'000)));
env(pay(issuer, borrower, MPT(1'000)));
env.close();
// Create vault and broker
auto const brokerInfo = createVaultAndBroker(env, MPT, broker);
// Create a loan first (this creates debt)
auto const keylet = keylet::loan(brokerInfo.brokerID, 1);
env(set(borrower, brokerInfo.brokerID, 10'000),
sig(sfCounterpartySignature, broker),
loanServiceFee(MPT(100).value()),
paymentInterval(100),
fee(XRP(100)));
env.close();
// Ensure broker has sufficient cover so brokerPayee == brokerOwner
// We need coverAvailable >= (debtTotal * coverRateMinimum)
// Deposit enough cover to ensure the fee goes to broker owner
// The default coverRateMinimum is 10%, so for a 10,000 loan we need
// at least 1,000 cover. Default cover is 1,000, so we add more to be
// safe.
auto const additionalCover = MPT(50'000).value();
env(loanBroker::coverDeposit(broker, brokerInfo.brokerID, STAmount{MPT, additionalCover}));
env.close();
// Verify broker owner is authorized
auto const brokerMpt = keylet::mptoken(mptt.issuanceID(), broker);
BEAST_EXPECT(env.le(brokerMpt) != nullptr);
// Broker owner unauthorizes.
// First, pay any positive balance to issuer to zero it out
auto const brokerBalance = env.balance(broker, MPT);
env(pay(broker, issuer, brokerBalance));
env.close();
// Then, unauthorize the MPT.
mptt.authorize({.account = broker, .flags = tfMPTUnauthorize});
env.close();
// Verify the MPT is unauthorized.
BEAST_EXPECT(env.le(brokerMpt) == nullptr);
// Now borrower tries to make a payment
// We should get a tesSUCCESS instead of a tecNO_AUTH.
auto const borrowerBalance = env.balance(borrower, MPT);
env(pay(borrower, keylet.key, MPT(10'100)), fee(XRP(100)), ter(tesSUCCESS));
env.close();
// Verify the MPT is still unauthorized.
BEAST_EXPECT(env.le(brokerMpt) == nullptr);
// Verify the service fee went to the broker pseudo-account
if (auto const brokerSle = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(brokerSle))
{
Account const pseudo("pseudo-account", brokerSle->at(sfAccount));
auto const balance = env.balance(pseudo, MPT);
// 1,000 default + 50,000 extra + 100 service fee from LoanPay
BEAST_EXPECTS(balance == MPT(51'100), to_string(Json::Value(balance)));
}
}
void
testLoanPayBrokerOwnerNoPermissionedDomainMPT()
{
testcase << "LoanPay Broker Owner without permissioned domain of the MPT";
using namespace jtx;
using namespace loan;
Account const issuer("issuer");
Account const borrower("borrower");
Account const broker("broker");
Env env(*this, all);
env.fund(XRP(20'000), issuer, broker, borrower);
env.close();
auto credType = "credential1";
pdomain::Credentials const credentials1{{issuer, credType}};
env(pdomain::setTx(issuer, credentials1));
env.close();
auto domainID = pdomain::getNewDomain(env.meta());
env(credentials::create(broker, issuer, credType));
env(credentials::accept(broker, issuer, credType));
env.close();
env(credentials::create(borrower, issuer, credType));
env(credentials::accept(borrower, issuer, credType));
env.close();
MPTTester mptt{env, issuer, mptInitNoFund};
mptt.create({
.flags = tfMPTCanClawback | tfMPTRequireAuth | tfMPTCanTransfer | tfMPTCanLock,
.domainID = domainID,
});
PrettyAsset const MPT{mptt.issuanceID()};
// Authorize broker and borrower
mptt.authorize({.account = broker});
mptt.authorize({.account = borrower});
env.close();
// Fund accounts
env(pay(issuer, broker, MPT(10'000'000)));
env(pay(issuer, borrower, MPT(1'000)));
env.close();
// Create vault and broker
auto const brokerInfo = createVaultAndBroker(env, MPT, broker);
// Create a loan first (this creates debt)
auto const keylet = keylet::loan(brokerInfo.brokerID, 1);
env(set(borrower, brokerInfo.brokerID, 10'000),
sig(sfCounterpartySignature, broker),
loanServiceFee(MPT(100).value()),
paymentInterval(100),
fee(XRP(100)));
env.close();
// Ensure broker has sufficient cover so brokerPayee == brokerOwner
// We need coverAvailable >= (debtTotal * coverRateMinimum)
// Deposit enough cover to ensure the fee goes to broker owner
// The default coverRateMinimum is 10%, so for a 10,000 loan we need
// at least 1,000 cover. Default cover is 1,000, so we add more to be
// safe.
auto const additionalCover = MPT(50'000).value();
env(loanBroker::coverDeposit(broker, brokerInfo.brokerID, STAmount{MPT, additionalCover}));
env.close();
// Verify broker owner is authorized
auto const brokerMpt = keylet::mptoken(mptt.issuanceID(), broker);
BEAST_EXPECT(env.le(brokerMpt) != nullptr);
// Remove the credentials for the Broker owner.
// First, pay any positive balance to issuer to zero it out
auto const brokerBalance = env.balance(broker, MPT);
env(pay(broker, issuer, brokerBalance));
env.close();
env(credentials::deleteCred(broker, broker, issuer, credType));
env.close();
// Make sure the broker is not authorized to hold the MPT after we
// deleted the credentials
env(pay(issuer, broker, MPT(1'000)), ter(tecNO_AUTH));
// Now borrower tries to make a payment
// We should get a tesSUCCESS instead of a tecNO_AUTH.
auto const borrowerBalance = env.balance(borrower, MPT);
env(pay(borrower, keylet.key, MPT(10'100)), fee(XRP(100)), ter(tesSUCCESS));
env.close();
// Verify broker is still not authorized
env(pay(issuer, broker, MPT(1'000)), ter(tecNO_AUTH));
// Verify the service fee went to the broker pseudo-account
if (auto const brokerSle = env.le(keylet::loanbroker(brokerInfo.brokerID));
BEAST_EXPECT(brokerSle))
{
Account const pseudo("pseudo-account", brokerSle->at(sfAccount));
auto const balance = env.balance(pseudo, MPT);
// 1,000 default + 50,000 extra + 100 service fee from LoanPay
BEAST_EXPECTS(balance == MPT(51'100), to_string(Json::Value(balance)));
}
}
void
testLoanSetBrokerOwnerNoPermissionedDomainMPT()
{
testcase << "LoanSet Broker Owner without permissioned domain of the MPT";
using namespace jtx;
using namespace loan;
Account const issuer("issuer");
Account const borrower("borrower");
Account const broker("broker");
Env env(*this, all);
env.fund(XRP(20'000), issuer, broker, borrower);
env.close();
auto credType = "credential1";
pdomain::Credentials const credentials1{{issuer, credType}};
env(pdomain::setTx(issuer, credentials1));
env.close();
auto domainID = pdomain::getNewDomain(env.meta());
// Add credentials for the broker and borrower
env(credentials::create(broker, issuer, credType));
env(credentials::accept(broker, issuer, credType));
env.close();
env(credentials::create(borrower, issuer, credType));
env(credentials::accept(borrower, issuer, credType));
env.close();
MPTTester mptt{env, issuer, mptInitNoFund};
mptt.create({
.flags = tfMPTCanClawback | tfMPTRequireAuth | tfMPTCanTransfer | tfMPTCanLock,
.domainID = domainID,
});
PrettyAsset const MPT{mptt.issuanceID()};
// Authorize broker and borrower
mptt.authorize({.account = broker});
mptt.authorize({.account = borrower});
env.close();
// Fund accounts
env(pay(issuer, broker, MPT(10'000'000)));
env(pay(issuer, borrower, MPT(1'000)));
env.close();
// Create vault and broker
auto const brokerInfo = createVaultAndBroker(env, MPT, broker);
// Remove the credentials for the Broker owner.
// Clear the balance first.
auto const brokerBalance = env.balance(broker, MPT);
env(pay(broker, issuer, brokerBalance));
env.close();
// Delete the credentials
env(credentials::deleteCred(broker, broker, issuer, credType));
env.close();
// Create a loan, this should fail for tecNO_AUTH
env(set(borrower, brokerInfo.brokerID, 10'000),
sig(sfCounterpartySignature, broker),
loanServiceFee(MPT(100).value()),
paymentInterval(100),
fee(XRP(100)),
ter(tecNO_AUTH));
env.close();
}
void
testSequentialFLCDepletion()
{
testcase << "First-Loss Capital Depletion on Sequential Defaults";
using namespace jtx;
using namespace loan;
using namespace loanBroker;
Env env(*this, all);
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const borrowerA{"borrowerA"};
Account const borrowerB{"borrowerB"};
env.fund(XRP(1'000'000), issuer, lender, borrowerA, borrowerB);
env.close();
PrettyAsset const asset = xrpIssue();
auto const vaultDepositAmount =
asset(200'000); // Enough for 2 x 50k loans plus interest/fees
auto const brokerInfo = createVaultAndBroker(
env,
asset,
lender,
{
.vaultDeposit = vaultDepositAmount.value(),
.debtMax = 0,
.coverRateMin = TenthBips32(20000), // 20%
.coverDeposit = 21'000,
.managementFeeRate = TenthBips16(100), // 0.1%
.coverRateLiquidation = TenthBips32(100000),
});
auto const brokerKeylet = brokerInfo.brokerKeylet();
// Create two identical loans: each 50,000 XRP principal (scaled down to
// avoid funding issues) Total DebtTotal will be ~100,000 XRP (principal
// + interest) Formula will calculate cover as: 100% × (20% × 100,000) =
// 20,000 XRP So we need FLC = 20,000 XRP to be fully consumed by first
// default
auto const principalAmount = Number(50'000);
auto const loanPaymentInterval = 2592000; // 30 days
auto const loanGracePeriod = 604800; // 7 days
// Create Loan A
auto loanATx = env.jt(
set(borrowerA, brokerKeylet.key, principalAmount),
sig(sfCounterpartySignature, lender),
interestRate(TenthBips32(500)), // 5%
paymentTotal(12),
loan::paymentInterval(loanPaymentInterval),
loan::gracePeriod(loanGracePeriod),
fee(XRP(10))); // Sufficient fee for multi-sig transaction
env(loanATx);
env.close();
auto const loanAKeylet = keylet::loan(brokerKeylet.key, 1);
// Create Loan B
auto loanBTx = env.jt(
set(borrowerB, brokerKeylet.key, principalAmount),
sig(sfCounterpartySignature, lender),
interestRate(TenthBips32(500)), // 5%
paymentTotal(12),
loan::paymentInterval(loanPaymentInterval),
loan::gracePeriod(loanGracePeriod),
fee(XRP(10))); // Sufficient fee for multi-sig transaction
env(loanBTx);
env.close();
auto const loanBKeylet = keylet::loan(brokerKeylet.key, 2);
auto loanASle = env.le(loanAKeylet);
if (!BEAST_EXPECT(loanASle))
return;
// Advance time past grace period for both loans to be defaultable
auto const loanANextDue = loanASle->at(sfNextPaymentDueDate);
auto const loanAGrace = loanASle->at(sfGracePeriod);
env.close(std::chrono::seconds{loanANextDue + loanAGrace + 60});
env(manage(lender, loanAKeylet.key, tfLoanDefault), ter(tesSUCCESS));
env.close();
// Verify Loan A is defaulted
loanASle = env.le(loanAKeylet);
if (!BEAST_EXPECT(loanASle))
return;
BEAST_EXPECT(loanASle->isFlag(lsfLoanDefault));
BEAST_EXPECT(loanASle->at(sfPaymentRemaining) == 0);
// Check broker state after first default (from committed ledger)
auto brokerSle = env.le(brokerKeylet);
if (!BEAST_EXPECT(brokerSle))
return;
auto const afterFirstDebtTotal = brokerSle->at(sfDebtTotal);
auto const afterFirstCoverAvailable = brokerSle->at(sfCoverAvailable);
// DebtTotal should have decreased by Loan A's debt
BEAST_EXPECT(afterFirstDebtTotal == 50'134);
// CoverAvailable should have decreased significantly
BEAST_EXPECT(afterFirstCoverAvailable == 946);
env(manage(lender, loanBKeylet.key, tfLoanDefault), ter(tesSUCCESS));
brokerSle = env.le(brokerKeylet);
if (!BEAST_EXPECT(brokerSle))
return;
auto const afterSecondDebtTotal = brokerSle->at(sfDebtTotal);
auto const afterSecondCoverAvailable = brokerSle->at(sfCoverAvailable);
BEAST_EXPECT(afterSecondDebtTotal == 0);
BEAST_EXPECT(afterSecondCoverAvailable == 0);
}
// Tests that vault withdrawals work correctly when the vault has unrealized
// loss from an impaired loan, ensuring the invariant check properly
// accounts for the loss.
void
testWithdrawReflectsUnrealizedLoss()
{
using namespace jtx;
using namespace loan;
using namespace std::chrono_literals;
testcase("Vault withdraw reflects sfLossUnrealized");
// Test constants
static constexpr std::int64_t INITIAL_FUNDING = 1'000'000;
static constexpr std::int64_t LENDER_INITIAL_IOU = 5'000'000;
static constexpr std::int64_t DEPOSITOR_INITIAL_IOU = 1'000'000;
static constexpr std::int64_t BORROWER_INITIAL_IOU = 100'000;
static constexpr std::int64_t DEPOSIT_AMOUNT = 5'000;
static constexpr std::int64_t PRINCIPAL_AMOUNT = 99;
static constexpr std::uint64_t EXPECTED_SHARES_PER_DEPOSITOR = 5'000'000'000;
static constexpr std::uint32_t PAYMENT_INTERVAL = 600;
static constexpr std::uint32_t PAYMENT_TOTAL = 2;
Env env(*this, all);
// Setup accounts
Account const issuer{"issuer"};
Account const lender{"lender"};
Account const depositorA{"lpA"};
Account const depositorB{"lpB"};
Account const borrower{"borrowerA"};
env.fund(XRP(INITIAL_FUNDING), issuer, lender, depositorA, depositorB, borrower);
env.close();
// Setup trust lines
PrettyAsset const iouAsset = issuer[iouCurrency];
env(trust(lender, iouAsset(10'000'000)));
env(trust(depositorA, iouAsset(10'000'000)));
env(trust(depositorB, iouAsset(10'000'000)));
env(trust(borrower, iouAsset(10'000'000)));
env.close();
// Fund accounts with IOUs
env(pay(issuer, lender, iouAsset(LENDER_INITIAL_IOU)));
env(pay(issuer, depositorA, iouAsset(DEPOSITOR_INITIAL_IOU)));
env(pay(issuer, depositorB, iouAsset(DEPOSITOR_INITIAL_IOU)));
env(pay(issuer, borrower, iouAsset(BORROWER_INITIAL_IOU)));
env.close();
// Create vault and broker, then add deposits from two depositors
auto const broker = createVaultAndBroker(env, iouAsset, lender);
Vault v{env};
env(v.deposit({
.depositor = depositorA,
.id = broker.vaultKeylet().key,
.amount = iouAsset(DEPOSIT_AMOUNT),
}),
ter(tesSUCCESS));
env(v.deposit({
.depositor = depositorB,
.id = broker.vaultKeylet().key,
.amount = iouAsset(DEPOSIT_AMOUNT),
}),
ter(tesSUCCESS));
env.close();
// Create a loan
auto const sleBroker = env.le(keylet::loanbroker(broker.brokerID));
if (!BEAST_EXPECT(sleBroker))
return;
auto const loanKeylet = keylet::loan(broker.brokerID, sleBroker->at(sfLoanSequence));
env(set(borrower, broker.brokerID, PRINCIPAL_AMOUNT),
sig(sfCounterpartySignature, lender),
paymentTotal(PAYMENT_TOTAL),
paymentInterval(PAYMENT_INTERVAL),
fee(env.current()->fees().base * 2),
ter(tesSUCCESS));
env.close();
// Impair the loan to create unrealized loss
env(manage(lender, loanKeylet.key, tfLoanImpair), ter(tesSUCCESS));
env.close();
// Verify unrealized loss is recorded in the vault
auto const vaultAfterImpair = env.le(broker.vaultKeylet());
if (!BEAST_EXPECT(vaultAfterImpair))
return;
BEAST_EXPECT(
vaultAfterImpair->at(sfLossUnrealized) == broker.asset(PRINCIPAL_AMOUNT).value());
// Helper to get share balance for a depositor
auto const shareAsset = vaultAfterImpair->at(sfShareMPTID);
auto const getShareBalance = [&](Account const& depositor) -> std::uint64_t {
auto const token = env.le(keylet::mptoken(shareAsset, depositor.id()));
return token ? token->getFieldU64(sfMPTAmount) : 0;
};
// Verify both depositors have equal shares
auto const sharesLpA = getShareBalance(depositorA);
auto const sharesLpB = getShareBalance(depositorB);
BEAST_EXPECT(sharesLpA == EXPECTED_SHARES_PER_DEPOSITOR);
BEAST_EXPECT(sharesLpB == EXPECTED_SHARES_PER_DEPOSITOR);
BEAST_EXPECT(sharesLpA == sharesLpB);
// Helper to attempt withdrawal
auto const attemptWithdrawShares = [&](Account const& depositor,
std::uint64_t shareAmount,
TER expected) {
STAmount const shareAmt{MPTIssue{shareAsset}, Number(shareAmount)};
env(v.withdraw(
{.depositor = depositor, .id = broker.vaultKeylet().key, .amount = shareAmt}),
ter(expected));
env.close();
};
// Regression test: Both depositors should successfully withdraw despite
// unrealized loss. Previously failed with invariant violation:
// "withdrawal must change vault and destination balance by equal
// amount". This was caused by sharesToAssetsWithdraw rounding down,
// creating a mismatch where vaultDeltaAssets * -1 != destinationDelta
// when unrealized loss exists.
attemptWithdrawShares(depositorA, sharesLpA, tesSUCCESS);
attemptWithdrawShares(depositorB, sharesLpB, tesSUCCESS);
}
public:
void
run() override
{
#if LOAN_TODO
testLoanPayLateFullPaymentBypassesPenalties();
testLoanCoverMinimumRoundingExploit();
#endif
testWithdrawReflectsUnrealizedLoss();
testInvalidLoanSet();
testCoverDepositWithdrawNonTransferableMPT();
testPoC_UnsignedUnderflowOnFullPayAfterEarlyPeriodic();
testDisabled();
testSelfLoan();
testIssuerLoan();
testLoanSet();
testLifecycle();
testServiceFeeOnBrokerDeepFreeze();
testRPC();
testInvalidLoanDelete();
testInvalidLoanManage();
testInvalidLoanPay();
testBatchBypassCounterparty();
testLoanPayComputePeriodicPaymentValidRateInvariant();
testAccountSendMptMinAmountInvariant();
testLoanPayDebtDecreaseInvariant();
testWrongMaxDebtBehavior();
testLoanPayComputePeriodicPaymentValidTotalInterestInvariant();
testDosLoanPay();
testLoanPayComputePeriodicPaymentValidTotalPrincipalPaidInvariant();
testLoanPayComputePeriodicPaymentValidTotalInterestPaidInvariant();
testLoanNextPaymentDueDateOverflow();
testRequireAuth();
testDustManipulation();
testRIPD3831();
testRIPD3459();
testRIPD3901();
testRIPD3902();
testRoundingAllowsUndercoverage();
testBorrowerIsBroker();
testIssuerIsBorrower();
testLimitExceeded();
testOverpaymentManagementFee();
testLoanPayBrokerOwnerMissingTrustline();
testLoanPayBrokerOwnerUnauthorizedMPT();
testLoanPayBrokerOwnerNoPermissionedDomainMPT();
testLoanSetBrokerOwnerNoPermissionedDomainMPT();
testSequentialFLCDepletion();
}
};
class LoanBatch_test : public Loan_test
{
protected:
beast::xor_shift_engine engine_;
std::uniform_int_distribution<> assetDist{0, 2};
std::uniform_int_distribution<std::int64_t> principalDist{100'000, 1'000'000'000};
std::uniform_int_distribution<std::uint32_t> interestRateDist{0, 10000};
std::uniform_int_distribution<> paymentTotalDist{12, 10000};
std::uniform_int_distribution<> paymentIntervalDist{60, 3600 * 24 * 30};
std::uniform_int_distribution<std::uint16_t> managementFeeRateDist{0, 10'000};
std::uniform_int_distribution<> serviceFeeDist{0, 20};
/*
# Generate parameters that are more likely to be valid
principal = Decimal(str(rand.randint(100000,
100'000'000))).quantize(ROUND_TARGET)
interest_rate = Decimal(rand.randint(1, 10000)) /
Decimal(100000)
payment_total = rand.randint(12, 10000)
payment_interval = Decimal(str(rand.randint(60, 2629746)))
interest_fee = Decimal(rand.randint(0, 100000)) /
Decimal(100000)
*/
void
testRandomLoan()
{
using namespace jtx;
Account const issuer("issuer");
Account const lender("lender");
Account const borrower("borrower");
// Determine all the random parameters at once
AssetType assetType = static_cast<AssetType>(assetDist(engine_));
auto const principalRequest = principalDist(engine_);
TenthBips16 managementFeeRate{managementFeeRateDist(engine_)};
auto const serviceFee = serviceFeeDist(engine_);
TenthBips32 interest{interestRateDist(engine_)};
auto const payTotal = paymentTotalDist(engine_);
auto const payInterval = paymentIntervalDist(engine_);
BrokerParameters brokerParams{
.vaultDeposit = principalRequest * 10,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
.managementFeeRate = managementFeeRate};
LoanParameters loanParams{
.account = lender,
.counter = borrower,
.principalRequest = principalRequest,
.serviceFee = serviceFee,
.interest = interest,
.payTotal = payTotal,
.payInterval = payInterval,
};
runLoan(assetType, brokerParams, loanParams);
}
public:
void
run() override
{
auto const numIterations = [s = arg()]() -> int {
int defaultNum = 5;
if (s.empty())
return defaultNum;
try
{
std::size_t pos = 0;
auto const r = stoi(s, &pos);
if (pos != s.size())
return defaultNum;
return r;
}
catch (...)
{
return defaultNum;
}
}();
using namespace jtx;
auto const updateInterval = std::min(numIterations / 5, 100);
for (int i = 0; i < numIterations; ++i)
{
if (i % updateInterval == 0)
testcase << "Random Loan Test iteration " << (i + 1) << "/" << numIterations;
testRandomLoan();
}
}
};
class LoanArbitrary_test : public LoanBatch_test
{
void
run() override
{
using namespace jtx;
BrokerParameters const brokerParams{
.vaultDeposit = 10000,
.debtMax = 0,
.coverRateMin = TenthBips32{0},
.managementFeeRate = TenthBips16{0},
.coverRateLiquidation = TenthBips32{0}};
LoanParameters const loanParams{
.account = Account("lender"),
.counter = Account("borrower"),
.principalRequest = Number{200000, -6},
.interest = TenthBips32{50000},
.payTotal = 2,
.payInterval = 200};
runLoan(AssetType::XRP, brokerParams, loanParams);
}
};
BEAST_DEFINE_TESTSUITE(Loan, tx, xrpl);
BEAST_DEFINE_TESTSUITE_MANUAL(LoanBatch, tx, xrpl);
BEAST_DEFINE_TESTSUITE_MANUAL(LoanArbitrary, tx, xrpl);
} // namespace test
} // namespace xrpl
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