removes side-effects from tryOverpayment

Author: Tapanito

src/test/app/LendingHelpers_test.cpp

@@ -668,74 +668,60 @@ class LendingHelpers_test : public beast::unit_test::suite
         std::cout << loanProperites.loanState.interestOutstanding()
                   << std::endl;
 
-        Number totalValueOutstanding =
-            loanProperites.loanState.valueOutstanding;
-        Number principalOutstanding =
-            loanProperites.loanState.principalOutstanding;
-        Number managementFeeOutstanding =
-            loanProperites.loanState.managementFeeDue;
         Number periodicPayment = loanProperites.periodicPayment;
 
         auto const ret = tryOverpayment(
             asset,
             loanScale,
             overpaymentComponents,
-            totalValueOutstanding,
-            principalOutstanding,
-            managementFeeOutstanding,
+            loanProperites.loanState,
             periodicPayment,
-            paymentInterval,
             periodicRate,
             paymentsRemaining,
             managementFeeRate,
             env.journal);
 
         BEAST_EXPECT(ret);
 
-        auto const& actualPaymentParts = *ret;
+        auto const& [actualPaymentParts, newLoanProperties] = *ret;
+        auto const newState = newLoanProperties.loanState;
 
         BEAST_EXPECTS(
             actualPaymentParts.valueChange ==
-                ((totalValueOutstanding - principalOutstanding -
-                  managementFeeOutstanding)) -
-                    loanProperites.loanState.interestDue,
+                newState.interestDue - loanProperites.loanState.interestDue,
             " valueChange mismatch: expected " +
                 to_string(
-                    (totalValueOutstanding - principalOutstanding -
-                     managementFeeOutstanding) -
+                    newState.interestDue -
                     loanProperites.loanState.interestDue) +
                 ", got " + to_string(actualPaymentParts.valueChange));
 
         BEAST_EXPECTS(
             actualPaymentParts.feePaid ==
                 loanProperites.loanState.managementFeeDue -
-                    managementFeeOutstanding,
+                    newState.managementFeeDue,
             " feePaid mismatch: expected " +
                 to_string(
                     loanProperites.loanState.managementFeeDue -
-                    managementFeeOutstanding) +
+                    newState.managementFeeDue) +
                 ", got " + to_string(actualPaymentParts.feePaid));
 
         BEAST_EXPECTS(
             actualPaymentParts.principalPaid ==
                 loanProperites.loanState.principalOutstanding -
-                    principalOutstanding,
+                    newState.principalOutstanding,
             " principalPaid mismatch: expected " +
                 to_string(
                     loanProperites.loanState.principalOutstanding -
-                    principalOutstanding) +
+                    newState.principalOutstanding) +
                 ", got " + to_string(actualPaymentParts.principalPaid));
 
         BEAST_EXPECTS(
             actualPaymentParts.interestPaid ==
-                loanProperites.loanState.interestDue -
-                    (totalValueOutstanding - principalOutstanding -
-                     managementFeeOutstanding),
+                loanProperites.loanState.interestDue - newState.interestDue,
             " interestPaid mismatch: expected " +
                 to_string(
                     loanProperites.loanState.interestDue -
-                    (totalValueOutstanding - principalOutstanding -
-                     managementFeeOutstanding)) +
+                    newState.interestDue) +
                 ", got " + to_string(actualPaymentParts.interestPaid));
     }
 

src/xrpld/app/misc/LendingHelpers.h

@@ -361,16 +361,13 @@ struct LoanStateDeltas
     nonNegative();
 };
 
-Expected<LoanPaymentParts, TER>
+Expected<std::pair<LoanPaymentParts, LoanProperties>, TER>
 tryOverpayment(
     Asset const& asset,
     std::int32_t loanScale,
     ExtendedPaymentComponents const& overpaymentComponents,
-    Number& totalValueOutstanding,
-    Number& principalOutstanding,
-    Number& managementFeeOutstanding,
-    Number& periodicPayment,
-    std::uint32_t paymentInterval,
+    LoanState const& roundedLoanState,
+    Number const& periodicPayment,
     Number const& periodicRate,
     std::uint32_t paymentRemaining,
     TenthBips16 const managementFeeRate,