From 13c98004487afe2b21d0e4e028f4abaaf8ebcc5e Mon Sep 17 00:00:00 2001
From: Vito <5780819+Tapanito@users.noreply.github.com>
Date: Wed, 15 Jul 2026 14:56:57 +0200
Subject: [PATCH] refactor: Address review feedback on payment-type split

Extract loanRatesFor() to replace the identical 4-line
managementFeeRate/interestRate/periodicRate preamble repeated in
makeFullPayment, makeLatePayment, and makeRegularPayment.

Clarify the constructLoanState(SLE::const_ref) doc comment to note
it's an overload of the 3-Number constructLoanState() above it,
rather than reading as a standalone function.
---
 include/xrpl/ledger/helpers/LendingHelpers.h  |  5 +--
 src/libxrpl/ledger/helpers/LendingHelpers.cpp | 32 ++++++++++---------
 2 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/include/xrpl/ledger/helpers/LendingHelpers.h b/include/xrpl/ledger/helpers/LendingHelpers.h
index 5f146c52df..8e0d11cccb 100644
--- a/include/xrpl/ledger/helpers/LendingHelpers.h
+++ b/include/xrpl/ledger/helpers/LendingHelpers.h
@@ -263,8 +263,9 @@ constructLoanState(
     Number const& principalOutstanding,
     Number const& managementFeeOutstanding);
 
-// Constructs a valid LoanState object from a Loan object, which always has
-// rounded values
+// Overload of constructLoanState() that reads the three tracked fields
+// directly from a Loan ledger object, which always holds rounded values,
+// rather than taking them as separate Number arguments.
 LoanState
 constructLoanState(SLE::const_ref loan);
 
diff --git a/src/libxrpl/ledger/helpers/LendingHelpers.cpp b/src/libxrpl/ledger/helpers/LendingHelpers.cpp
index de2f29b8c3..0bd3befe16 100644
--- a/src/libxrpl/ledger/helpers/LendingHelpers.cpp
+++ b/src/libxrpl/ledger/helpers/LendingHelpers.cpp
@@ -1408,6 +1408,20 @@ computeOverpaymentComponents(
     return result;
 }
 
+/* Derives the two rate values every make*Payment() helper needs: the
+ * broker's management fee rate, and the loan's periodic (per-payment-period)
+ * interest rate.
+ */
+std::pair<TenthBips16, Number>
+loanRatesFor(SLE::const_ref loan, SLE::const_ref brokerSle)
+{
+    TenthBips16 const managementFeeRate{brokerSle->at(sfManagementFeeRate)};
+    TenthBips32 const interestRate{loan->at(sfInterestRate)};
+    Number const periodicRate = loanPeriodicRate(interestRate, loan->at(sfPaymentInterval));
+    XRPL_ASSERT(interestRate == 0 || periodicRate > 0, "xrpl::detail::loanRatesFor : valid rate");
+    return {managementFeeRate, periodicRate};
+}
+
 /* Handles a full (early payoff) payment. Implements the "full payment"
  * branch of the make_payment function from the XLS-66 spec, Section
  * 3.2.4.4.
@@ -1421,11 +1435,7 @@ makeFullPayment(
     STAmount const& amount,
     beast::Journal j)
 {
-    TenthBips16 const managementFeeRate{brokerSle->at(sfManagementFeeRate)};
-    TenthBips32 const interestRate{loan->at(sfInterestRate)};
-    Number const periodicRate = loanPeriodicRate(interestRate, loan->at(sfPaymentInterval));
-    XRPL_ASSERT(
-        interestRate == 0 || periodicRate > 0, "xrpl::detail::makeFullPayment : valid rate");
+    auto const [managementFeeRate, periodicRate] = loanRatesFor(loan, brokerSle);
 
     auto const fullPaymentComponents =
         computeFullPayment(asset, view, loan, periodicRate, amount, managementFeeRate, j);
@@ -1450,11 +1460,7 @@ makeLatePayment(
     STAmount const& amount,
     beast::Journal j)
 {
-    TenthBips16 const managementFeeRate{brokerSle->at(sfManagementFeeRate)};
-    TenthBips32 const interestRate{loan->at(sfInterestRate)};
-    Number const periodicRate = loanPeriodicRate(interestRate, loan->at(sfPaymentInterval));
-    XRPL_ASSERT(
-        interestRate == 0 || periodicRate > 0, "xrpl::detail::makeLatePayment : valid rate");
+    auto const [managementFeeRate, periodicRate] = loanRatesFor(loan, brokerSle);
 
     Number const serviceFee = loan->at(sfLoanServiceFee);
     ExtendedPaymentComponents const periodic{
@@ -1496,11 +1502,7 @@ makeRegularPayment(
         "xrpl::detail::makeRegularPayment",
         "regular payment type");
 
-    TenthBips16 const managementFeeRate{brokerSle->at(sfManagementFeeRate)};
-    TenthBips32 const interestRate{loan->at(sfInterestRate)};
-    Number const periodicRate = loanPeriodicRate(interestRate, loan->at(sfPaymentInterval));
-    XRPL_ASSERT(
-        interestRate == 0 || periodicRate > 0, "xrpl::detail::makeRegularPayment : valid rate");
+    auto const [managementFeeRate, periodicRate] = loanRatesFor(loan, brokerSle);
 
     std::int32_t const loanScale = loan->at(sfLoanScale);
     Number const serviceFee = loan->at(sfLoanServiceFee);