FINERACT-2107: Allow interest rate change on fully paid installment for Progressive loans

fineract-progressive-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/rescheduleloan/data/ProgressiveLoanRescheduleRequestDataValidator.java

@@ -29,7 +29,6 @@ import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.Loan
 import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.LoanRescheduleRequestDataValidatorImpl.validateRescheduleReasonComment;
 import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.LoanRescheduleRequestDataValidatorImpl.validateRescheduleReasonId;
 import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.LoanRescheduleRequestDataValidatorImpl.validateRescheduleRequestStatus;
-import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.LoanRescheduleRequestDataValidatorImpl.validateReschedulingInstallment;
 import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.LoanRescheduleRequestDataValidatorImpl.validateSubmittedOnDate;
 import static org.apache.fineract.portfolio.loanaccount.rescheduleloan.data.LoanRescheduleRequestDataValidatorImpl.validateSupportedParameters;
 
@@ -120,6 +119,14 @@ public class ProgressiveLoanRescheduleRequestDataValidator implements LoanResche
         }
     }
 
+    @Override
+    public void validateReschedulingInstallment(DataValidatorBuilder dataValidatorBuilder, LoanRepaymentScheduleInstallment installment) {
+        if (installment == null) {
+            dataValidatorBuilder.reset().parameter(RescheduleLoansApiConstants.rescheduleFromDateParamName)
+                    .failWithCode("repayment.schedule.installment.does.not.exist", "Repayment schedule installment does not exist");
+        }
+    }
+
     private void validateUnsupportedParams(JsonElement jsonElement, DataValidatorBuilder dataValidatorBuilder) {
         final var unsupportedFields = List.of(RescheduleLoansApiConstants.graceOnPrincipalParamName, //
                 RescheduleLoansApiConstants.graceOnInterestParamName, //

fineract-progressive-loan/src/test/java/org/apache/fineract/portfolio/loanaccount/rescheduleloan/data/ProgressiveLoanRescheduleRequestDataValidatorTest.java

@@ -0,0 +1,83 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.fineract.portfolio.loanaccount.rescheduleloan.data;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import org.apache.fineract.infrastructure.core.data.DataValidatorBuilder;
+import org.apache.fineract.infrastructure.core.serialization.FromJsonHelper;
+import org.apache.fineract.portfolio.loanaccount.domain.LoanRepaymentScheduleInstallment;
+import org.apache.fineract.portfolio.loanaccount.rescheduleloan.RescheduleLoansApiConstants;
+import org.apache.fineract.portfolio.loanaccount.rescheduleloan.domain.LoanRescheduleRequestRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.junit.jupiter.MockitoSettings;
+import org.mockito.quality.Strictness;
+
+@ExtendWith(MockitoExtension.class)
+@MockitoSettings(strictness = Strictness.LENIENT)
+class ProgressiveLoanRescheduleRequestDataValidatorTest {
+
+    @Mock
+    private DataValidatorBuilder dataValidatorBuilder;
+
+    @Mock
+    private LoanRepaymentScheduleInstallment installment;
+
+    @Mock
+    private FromJsonHelper fromJsonHelper;
+
+    @Mock
+    private LoanRescheduleRequestRepository loanRescheduleRequestRepository;
+
+    private ProgressiveLoanRescheduleRequestDataValidator progressiveLoanRescheduleRequestDataValidator;
+
+    @BeforeEach
+    void setUp() {
+        progressiveLoanRescheduleRequestDataValidator = new ProgressiveLoanRescheduleRequestDataValidator(fromJsonHelper,
+                loanRescheduleRequestRepository);
+        when(dataValidatorBuilder.reset()).thenReturn(dataValidatorBuilder);
+        when(dataValidatorBuilder.parameter(anyString())).thenReturn(dataValidatorBuilder);
+    }
+
+    @Test
+    void shouldFailWhenInstallmentIsNull() {
+        progressiveLoanRescheduleRequestDataValidator.validateReschedulingInstallment(dataValidatorBuilder, null);
+
+        verify(dataValidatorBuilder).reset();
+        verify(dataValidatorBuilder).parameter(RescheduleLoansApiConstants.rescheduleFromDateParamName);
+        verify(dataValidatorBuilder).failWithCode("repayment.schedule.installment.does.not.exist",
+                "Repayment schedule installment does not exist");
+    }
+
+    @Test
+    void shouldNotFailWhenInstallmentIsNotNull() {
+        assertDoesNotThrow(
+                () -> progressiveLoanRescheduleRequestDataValidator.validateReschedulingInstallment(dataValidatorBuilder, installment));
+
+        verify(dataValidatorBuilder, never()).failWithCode(anyString(), anyString());
+    }
+}