E2E Tests for Loan Lifecycle Flow

[Josue19-08]

🔖 Title

E2E Tests for Loan Lifecycle Flow

---

📄 Description

Create end-to-end integration tests for the complete loan lifecycle from quote to repayment. Mock blockchain interactions and use test database. This issue can be completed independently once issues #55, #56, #57, #58, #59, #62, and #63 are implemented.

Related to: Meta-issue #68

---

✅ Tasks to complete

• Test loan quote endpoint (POST /loans/quote)
• Test available credit calculation (GET /loans/available-credit)
• Test loan creation endpoint (POST /loans/create)
• Test transaction submission for loan creation (POST /transactions/submit)
• Test transaction status check (GET /transactions/:hash)
• Test listing user loans (GET /loans/my-loans)
• Test loan repayment endpoint (POST /loans/:loanId/pay)
• Test complete flow: quote → create → submit → confirm → list → repay → complete
• Test validation errors (inactive merchant, insufficient credit)
• Verify database state changes (pending → active → completed)
• Mock Soroban contract interactions
• Clean up test data after tests

---

📚 Documentation/context for AI

(This link never should removed)
https://github.com/TrustUp-app/TrustUp-API/tree/main/docs

Relevant documentation:

• https://github.com/TrustUp-app/TrustUp-API/blob/main/docs/development/testing-structure.md
• https://github.com/TrustUp-app/TrustUp-API/blob/main/docs/architecture/blockchain-layer.md

Dependencies:

• Issue Enhanced Loan Quote Calculation Endpoint #55 (Loan quote) must be implemented
• Issue Create BNPL Loan Endpoint #56 (Create loan) must be implemented
• Issue List User Loans Endpoint #57 (List loans) must be implemented
• Issue Loan Repayment Endpoint #58 (Loan repayment) must be implemented
• Issue Available Credit Calculation Endpoint #59 (Available credit) must be implemented
• Issue Transaction Submission to Stellar Network #62 (Submit transaction) must be implemented
• Issue Transaction Status Query Endpoint #63 (Transaction status) must be implemented

---

🗒️ Additional notes

Acceptance Criteria:

• All E2E tests pass
• Complete loan lifecycle works end-to-end
• Database state transitions are validated
• Blockchain mocks return predictable responses
• Error scenarios are tested
• Test data is cleaned up