fix: Add AMMv1_3 amendment (#5203)

* Add AMM bid/create/deposit/swap/withdraw/vote invariants:
  - Deposit, Withdrawal invariants: `sqrt(asset1Balance * asset2Balance) >= LPTokens`.
  - Bid: `sqrt(asset1Balance * asset2Balance) > LPTokens` and the pool balances don't change.
  - Create: `sqrt(asset1Balance * assetBalance2) == LPTokens`.
  - Swap: `asset1BalanceAfter * asset2BalanceAfter >= asset1BalanceBefore * asset2BalanceBefore`
     and `LPTokens` don't change.
  - Vote: `LPTokens` and pool balances don't change.
  - All AMM and swap transactions: amounts and tokens are greater than zero, except on withdrawal if all tokens
    are withdrawn.
* Add AMM deposit and withdraw rounding to ensure AMM invariant:
  - On deposit, tokens out are rounded downward and deposit amount is rounded upward.
  - On withdrawal, tokens in are rounded upward and withdrawal amount is rounded downward.
* Add Order Book Offer invariant to verify consumed amounts. Consumed amounts are less than the offer.
* Fix Bid validation. `AuthAccount` can't have duplicate accounts or the submitter account.

src/test/jtx/impl/AMM.cpp

@@ -20,6 +20,7 @@
 #include <test/jtx/AMM.h>
 #include <test/jtx/Env.h>
 
+#include <xrpld/app/misc/AMMHelpers.h>
 #include <xrpld/app/misc/AMMUtils.h>
 #include <xrpld/rpc/detail/RPCHelpers.h>
 
@@ -39,12 +40,16 @@ number(STAmount const& a)
     return a;
 }
 
-static IOUAmount
-initialTokens(STAmount const& asset1, STAmount const& asset2)
+IOUAmount
+AMM::initialTokens()
 {
-    auto const product = number(asset1) * number(asset2);
-    return (IOUAmount)(product.mantissa() >= 0 ? root2(product)
-                                               : root2(-product));
+    if (!env_.enabled(fixAMMv1_3))
+    {
+        auto const product = number(asset1_) * number(asset2_);
+        return (IOUAmount)(product.mantissa() >= 0 ? root2(product)
+                                                   : root2(-product));
+    }
+    return getLPTokensBalance();
 }
 
 AMM::AMM(
@@ -65,7 +70,6 @@ AMM::AMM(
     , asset1_(asset1)
     , asset2_(asset2)
     , ammID_(keylet::amm(asset1_.issue(), asset2_.issue()).key)
-    , initialLPTokens_(initialTokens(asset1, asset2))
     , log_(log)
     , doClose_(close)
     , lastPurchasePrice_(0)
@@ -78,6 +82,7 @@ AMM::AMM(
           asset1_.issue().currency,
           asset2_.issue().currency,
           ammAccount_))
+    , initialLPTokens_(initialTokens())
 {
 }
 

src/test/jtx/impl/AMMTest.cpp

@@ -19,6 +19,7 @@
 
 #include <test/jtx/AMM.h>
 #include <test/jtx/AMMTest.h>
+#include <test/jtx/CaptureLogs.h>
 #include <test/jtx/Env.h>
 #include <test/jtx/pay.h>
 
@@ -105,15 +106,31 @@ AMMTestBase::testAMM(
     std::uint16_t tfee,
     std::optional<jtx::ter> const& ter,
     std::vector<FeatureBitset> const& vfeatures)
+{
+    testAMM(
+        std::move(cb),
+        TestAMMArg{
+            .pool = pool, .tfee = tfee, .ter = ter, .features = vfeatures});
+}
+
+void
+AMMTestBase::testAMM(
+    std::function<void(jtx::AMM&, jtx::Env&)>&& cb,
+    TestAMMArg const& arg)
 {
     using namespace jtx;
 
-    for (auto const& features : vfeatures)
+    std::string logs;
+
+    for (auto const& features : arg.features)
     {
-        Env env{*this, features};
+        Env env{
+            *this,
+            features,
+            arg.noLog ? std::make_unique<CaptureLogs>(&logs) : nullptr};
 
         auto const [asset1, asset2] =
-            pool ? *pool : std::make_pair(XRP(10000), USD(10000));
+            arg.pool ? *arg.pool : std::make_pair(XRP(10000), USD(10000));
         auto tofund = [&](STAmount const& a) -> STAmount {
             if (a.native())
             {
@@ -143,7 +160,7 @@ AMMTestBase::testAMM(
             alice,
             asset1,
             asset2,
-            CreateArg{.log = false, .tfee = tfee, .err = ter});
+            CreateArg{.log = false, .tfee = arg.tfee, .err = arg.ter});
         if (BEAST_EXPECT(
                 ammAlice.expectBalances(asset1, asset2, ammAlice.tokens())))
             cb(ammAlice, env);