Add health endpoint dependency-graph tests for degraded and down states

[thlpkee20-wq]

Description

src/routes/health.ts builds a HealthDependencyGraph across database, stellar-horizon, and db-pool dependencies and returns 200/503 based on aggregate status, but the degraded vs unhealthy aggregation and latency reporting need fuller test coverage. Expand src/routes/health.test.ts to exercise each dependency status combination.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review
• Relevant code: src/routes/health.ts, src/routes/health.test.ts, src/db/client.ts
• Aggregate must be unhealthy/503 when any required dependency is down

Suggested execution

• Fork the repo and create a branch
• git checkout -b test/health-dependency-graph
• Implement changes
  • Inject mock db health and Stellar checkers returning up/degraded/down
  • Assert aggregate status and HTTP code for each combination
  • Assert latencyMs and dependsOn are populated
• Validate security and correctness assumptions

Test and commit

• Run tests
  • npm test
• Cover edge cases
  • DB up + Horizon down, all degraded, checker throws, missing optional dependency
• Include test output and notes

Example commit message

test: cover health dependency-graph aggregation

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[omolobamoyinoluwa-max]

@omolobamoyinoluwa-max has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi, I am interested in working on this issue. Kindly assign it to me. You can be rest assured that the job will be solved clean and all test passing. Thank you.

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Congratulations, @omolobamoyinoluwa-max! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

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