fix: align repay function name between XDR builder and transaction checker

src/jobs/transaction-status-checker/transaction-status-checker.service.ts

@@ -535,7 +535,7 @@ export class TransactionStatusCheckerService {
         };
       }
 
-      if (functionName === 'repay_loan') {
+      if (functionName === 'repay_installment') {
         const loanId = nativeArgs[1] as string;
         const rawAmount = nativeArgs[2];
         const amount = typeof rawAmount === 'bigint' ? Number(rawAmount) / 10_000_000 :

src/modules/loans/dto/loan-payment-response.dto.ts

@@ -27,7 +27,7 @@ export class LoanPaymentPreviewDto {
  */
 export class LoanPaymentResponseDto {
   @ApiProperty({
-    description: 'Unsigned XDR transaction for the repay_loan() Soroban call',
+    description: 'Unsigned XDR transaction for the repay_installment() Soroban call',
     example: 'AAAAAgAAAAA...',
   })
   unsignedXdr: string;

src/modules/loans/loans.controller.ts

@@ -184,7 +184,7 @@ export class LoansController {
   @ApiOperation({
     summary: 'Make a loan repayment',
     description:
-      'Validates the payment, constructs an unsigned Soroban repay_loan() transaction, and returns it alongside a payment preview. The mobile app must sign the XDR and submit the signed transaction back to the network. Requires JWT authentication.',
+      'Validates the payment, constructs an unsigned Soroban repay_installment() transaction, and returns it alongside a payment preview. The mobile app must sign the XDR and submit the signed transaction back to the network. Requires JWT authentication.',
   })
   @ApiResponse({
     status: 200,

src/modules/loans/loans.service.ts

@@ -213,7 +213,7 @@ export class LoansService {
       });
     }
 
-    return this.creditLineContractClient.buildRepayLoanTx(
+    return this.creditLineContractClient.buildRepayInstallmentTx(
       wallet,
       loan.loan_id,
       amount,

src/stellar/contracts/clients/creditline.client.ts

@@ -66,7 +66,7 @@ export class CreditLineContractClient {
     return prepared.toXDR();
   }
 
-  async buildRepayLoanTx(userWallet: string, loanId: string, amount: number): Promise<string> {
+  async buildRepayInstallmentTx(userWallet: string, loanId: string, amount: number): Promise<string> {
     this.ensureConfigured();
 
     try {
@@ -97,7 +97,7 @@ export class CreditLineContractClient {
       if (error instanceof ContractNotConfiguredError) {
         throw error;
       }
-      this.logger.error(`Failed to build repay_loan transaction: ${error.message}`);
+      this.logger.error(`Failed to build repay_installment transaction: ${error.message}`);
       throw new ContractTxBuildError('repayment');
     }
   }

src/stellar/contracts/interfaces/creditline.interface.ts

@@ -16,7 +16,7 @@ export interface ICreditLineClient {
     params: CreateLoanParams,
   ): Promise<string>;
 
-  buildRepayLoanTx(
+  buildRepayInstallmentTx(
     userWallet: string,
     loanId: string,
     amount: number,

src/stellar/contracts/mocks/creditline.mock.ts

@@ -9,7 +9,7 @@ export class MockCreditLineContractClient {
     },
   );
 
-  buildRepayLoanTx = jest.fn(
+  buildRepayInstallmentTx = jest.fn(
     async (_userWallet: string, _loanId: string, _amount: number): Promise<string> => {
       return 'AAAAAgAAAQAAAAAAAAAAiZ3TgwAAAAAyMZyAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==';
     },

test/e2e/helpers/test-setup.ts

@@ -320,7 +320,7 @@ export async function buildTestApp(): Promise<{
     buildCreateLoanTransaction: jest
       .fn()
       .mockResolvedValue('AAAAAgAAAQAAAAAAAAAAiZ3TgwAAAAAyMZyAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=='),
-    buildRepayLoanTx: jest
+    buildRepayInstallmentTx: jest
       .fn()
       .mockResolvedValue('AAAAAgAAAQAAAAAAAAAAiZ3TgwAAAAAyMZyAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=='),
     getScore: jest.fn().mockResolvedValue(75),

test/e2e/modules/loans/loan-lifecycle.e2e-spec.ts

@@ -75,7 +75,7 @@ describe('Loan Lifecycle Flow (e2e)', () => {
 
   const mockCreditLineContract = {
     buildCreateLoanTransaction: jest.fn(),
-    buildRepayLoanTx: jest.fn(),
+    buildRepayInstallmentTx: jest.fn(),
   };
 
   const mockTransactionsService = {
@@ -288,7 +288,7 @@ describe('Loan Lifecycle Flow (e2e)', () => {
       return `xdr-loan-create-${payload.loanId}`;
     });
 
-    mockCreditLineContract.buildRepayLoanTx.mockImplementation(async (_wallet, loanId, amount) => {
+    mockCreditLineContract.buildRepayInstallmentTx.mockImplementation(async (_wallet, loanId, amount) => {
       return `xdr-loan-repay-${loanId}-${amount}`;
     });
 

test/unit/modules/loans/loans.service.spec.ts

@@ -110,7 +110,7 @@ describe('LoansService', () => {
     mockSupabaseFrom.insert.mockResolvedValue({ error: null });
     mockSupabaseFrom.update.mockReturnThis();
     mockCreditLineContractClient.buildCreateLoanTransaction.mockResolvedValue('AAAAAgAAAAC...');
-    mockCreditLineContractClient.buildRepayLoanTx.mockResolvedValue('AAAAAgAAAAA...');
+    mockCreditLineContractClient.buildRepayInstallmentTx.mockResolvedValue('AAAAAgAAAAA...');
   });
 
   afterEach(() => {
@@ -386,7 +386,7 @@ describe('LoansService', () => {
           willComplete: false,
         },
       });
-      expect(mockCreditLineContractClient.buildRepayLoanTx).toHaveBeenCalledWith(
+      expect(mockCreditLineContractClient.buildRepayInstallmentTx).toHaveBeenCalledWith(
         validWallet,
         'chain-loan-1',
         108.33,

test/unit/stellar/contract-function-name.spec.ts

@@ -0,0 +1,66 @@
+jest.unmock('stellar-sdk');
+
+import * as StellarSdk from 'stellar-sdk';
+import { CreditLineContractClient } from '../../../src/stellar/contracts/clients/creditline.client';
+import { SorobanService } from '../../../src/blockchain/soroban/soroban.service';
+import { ConfigService } from '@nestjs/config';
+
+describe('Repayment function name alignment', () => {
+  let client: CreditLineContractClient;
+  let mockServer: { prepareTransaction: jest.Mock; getAccount: jest.Mock };
+
+  const testContractId = 'CC4C3VI4FS6J5PP7OQN4ZC3WWBYMAISPRN4VYTCZ2J7CHI3255OM32LT';
+  const testNetwork = 'Test SDF Network ; September 2015';
+  const testWallet = 'GAZBSUBUXTD6YVYXECZRW2R6K7MOU5FGU2SVYXKYWOLT5H3JIRD54EZL';
+
+  beforeEach(() => {
+    mockServer = {
+      prepareTransaction: jest.fn(async (tx: StellarSdk.Transaction) => {
+        return { toXDR: () => tx.toXDR() };
+      }),
+      getAccount: jest.fn().mockResolvedValue({}),
+    };
+
+    const mockSorobanService = {
+      getServer: jest.fn().mockReturnValue(mockServer),
+      getNetworkPassphrase: jest.fn().mockReturnValue(testNetwork),
+    };
+
+    const mockConfigService = {
+      get: jest.fn((key: string) => {
+        if (key === 'CREDIT_LINE_CONTRACT_ID' || key === 'CREDITLINE_CONTRACT_ID') {
+          return testContractId;
+        }
+        return undefined;
+      }),
+    };
+
+    client = new CreditLineContractClient(
+      mockSorobanService as unknown as SorobanService,
+      mockConfigService as unknown as ConfigService,
+    );
+  });
+
+  it('XDR builder and transaction checker use the same function name: repay_installment with 3 args', async () => {
+    const xdr = await client.buildRepayInstallmentTx(testWallet, 'test-loan-123', 100);
+
+    const tx = StellarSdk.TransactionBuilder.fromXDR(xdr, testNetwork);
+    const innerTx =
+      tx instanceof StellarSdk.FeeBumpTransaction ? tx.innerTransaction : tx;
+    const op = innerTx.operations[0];
+
+    expect(op.type).toBe('invokeHostFunction');
+
+    const invocation = ((op as unknown as { func: unknown }).func as {
+      _value?: { _attributes?: { functionName?: { toString?: () => string }; args?: unknown[] } };
+    })?._value?._attributes;
+
+    expect(invocation).toBeDefined();
+
+    const functionName = invocation!.functionName?.toString?.();
+    expect(functionName).toBe('repay_installment');
+
+    const args = invocation!.args as unknown[];
+    expect(args).toHaveLength(3);
+  });
+});