FINERACT-2556: Prevent no-op updates for approved amount modification

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/service/LoanApprovedAmountWritePlatformServiceImpl.java

@@ -27,6 +27,7 @@
 import org.apache.fineract.infrastructure.core.data.CommandProcessingResultBuilder;
 import org.apache.fineract.infrastructure.event.business.domain.loan.LoanApprovedAmountChangedBusinessEvent;
 import org.apache.fineract.infrastructure.event.business.service.BusinessEventNotifierService;
+import org.apache.fineract.portfolio.common.service.Validator;
 import org.apache.fineract.portfolio.loanaccount.api.LoanApiConstants;
 import org.apache.fineract.portfolio.loanaccount.domain.Loan;
 import org.apache.fineract.portfolio.loanaccount.domain.LoanApprovedAmountHistory;
@@ -58,6 +59,12 @@ public CommandProcessingResult modifyLoanApprovedAmount(final Long loanId, final
 
         BigDecimal newApprovedAmount = command.bigDecimalValueOfParameterNamed(LoanApiConstants.amountParameterName);
 
+        if (newApprovedAmount.compareTo(loan.getApprovedPrincipal()) == 0) {
+            Validator.validateOrThrowDomainViolation("loan.approved.amount",
+                    baseDataValidator -> baseDataValidator.reset().parameter(LoanApiConstants.amountParameterName).value(newApprovedAmount)
+                            .failWithCode("must.be.different.from.current.approved.amount"));
+        }
+
         LoanApprovedAmountHistory loanApprovedAmountHistory = new LoanApprovedAmountHistory(loan.getId(), newApprovedAmount,
                 loan.getApprovedPrincipal());
 
@@ -99,6 +106,12 @@ public CommandProcessingResult modifyLoanAvailableDisbursementAmount(Long loanId
                 .add(newAvailableDisbursementAmount);
         changes.put("newApprovedAmount", newApprovedAmount);
 
+        if (newApprovedAmount.compareTo(loan.getApprovedPrincipal()) == 0) {
+            Validator.validateOrThrowDomainViolation("loan.approved.amount",
+                    baseDataValidator -> baseDataValidator.reset().parameter(LoanApiConstants.amountParameterName).value(newApprovedAmount)
+                            .failWithCode("must.be.different.from.current.approved.amount"));
+        }
+
         LoanApprovedAmountHistory loanApprovedAmountHistory = new LoanApprovedAmountHistory(loan.getId(), newApprovedAmount,
                 loan.getApprovedPrincipal());
 

integration-tests/src/test/java/org/apache/fineract/integrationtests/LoanModifyApprovedAmountTest.java

@@ -127,6 +127,30 @@ public void testValidLoanApprovedAmountModificationInvalidLoanStatus() {
         });
     }
 
+    @Test
+    public void testShouldFailWhenApprovedAmountIsSame() {
+
+        final PostClientsResponse client = clientHelper.createClient(ClientHelper.defaultClientCreationRequest());
+        final PostLoanProductsResponse loanProductsResponse = loanProductHelper.createLoanProduct(create4IProgressive());
+
+        runAt("1 January 2024", () -> {
+            Long loanId = applyAndApproveProgressiveLoan(client.getClientId(), loanProductsResponse.getResourceId(), "1 January 2024",
+                    1000.0, 10.0, 4, null);
+
+            disburseLoan(loanId, BigDecimal.valueOf(100), "1 January 2024");
+
+            GetLoansLoanIdResponse loanDetails = loanTransactionHelper.getLoanDetails(loanId);
+            BigDecimal sameApprovedAmount = loanDetails.getApprovedPrincipal();
+
+            CallFailedRuntimeException exception = assertThrows(CallFailedRuntimeException.class,
+                    () -> modifyLoanApprovedAmount(loanId, sameApprovedAmount));
+
+            assertEquals(403, exception.getResponse().code());
+            assertTrue(exception.getMessage()
+                    .contains("validation.msg.loan.approved.amount.amount.must.be.different.from.current.approved.amount"));
+        });
+    }
+
     @Test
     public void testModifyLoanApprovedAmountTooHigh() {
         BigDecimal twoThousand = BigDecimal.valueOf(2000.0);