Unit Tests for LoanService

[Josue19-08]

🔖 Title

Unit Tests for LoanService

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📄 Description

Write comprehensive unit tests for the LoanService covering loan quote calculation, loan creation transaction building, and repayment logic. Mock blockchain RPC calls and database operations. This issue can be completed independently once issues #55, #56, #57, #58, and #59 are implemented.

Related to: Meta-issue #67

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✅ Tasks to complete

• Test loan quote calculation with different reputation tiers
• Test interest rate mapping from reputation score
• Test payment schedule generation
• Test loan creation transaction building (XDR construction)
• Test guarantee amount calculation (20% of purchase)
• Test repayment transaction building
• Test remaining balance calculations
• Test validation of merchant existence and active status
• Test credit limit enforcement
• Mock Soroban contract calls
• Mock database queries for loans and merchants
• Test error scenarios (inactive merchant, insufficient credit)
• Achieve 80%+ coverage for LoanService

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📚 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) should be implemented
• Issue Create BNPL Loan Endpoint #56 (Create loan) should be implemented
• Issue List User Loans Endpoint #57 (List loans) should be implemented
• Issue Loan Repayment Endpoint #58 (Loan repayment) should be implemented
• Issue Available Credit Calculation Endpoint #59 (Available credit) should be implemented

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🗒️ Additional notes

Acceptance Criteria:

• All test cases pass
• Code coverage for LoanService is at least 80%
• Blockchain calls are properly mocked
• XDR construction is validated
• Complex calculations (interest, schedules) are tested with edge cases

[drips-wave]

Congratulations, @AliFikan94! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on April 29, 2026.

🧑‍💻 @AliFikan94: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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[Luchistack]

@Luchistack has applied to work on this issue as part of the Stellar Wave Program's 4th wave.

I would love to work on this project

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Luchistack to this issue.

[toni-toni2]

@toni-toni2 has applied to work on this issue as part of the Stellar Wave Program's 4th wave.

Can I take this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @toni-toni2 to this issue.