Add test coverage for usage recording, accumulation, saturation, and the disabled guard

[mikewheeleer]

Test the usage recording and accumulation endpoints

Description

The core metering path — POST /api/v1/usage, GET /api/v1/usage/:agent/:serviceId, and the Math.min(Number.MAX_SAFE_INTEGER, prev + requests) saturation logic in src/index.ts — is largely untested in src/health.test.ts. The 409 service_disabled guard, the accumulation across repeated calls, and the read-back of a never-seen pair (returns total: 0) all lack coverage. Since this is the ledger the billing and settlement math depend on, it deserves thorough tests.

Requirements and context

• Repository scope: Agentpay-Org/Agentpay-backend only.
• Cover POST /api/v1/usage: 201 happy path, validation 400s for bad agent/serviceId/requests, and the 409 service_disabled path after toggling disabled.
• Cover repeated posts accumulating into one total, and the read endpoint returning the running total (and 0 for unknown pairs).
• Exercise the saturation behaviour near Number.MAX_SAFE_INTEGER deterministically (seed a near-max total, then add).
• Assert the standard 400 invalid_request shape with a requestId on every validation failure.

Suggested execution

• Fork the repo and create a branch
• git checkout -b test/testing-41-usage-recording
• Implement changes
  • Write comprehensive tests in: new src/usage.test.ts using supertest against the exported app.
  • Write code in: no production change expected; if a real bug surfaces, fix it and note it in the PR.
  • Add documentation: none beyond test descriptions.
  • Add clear describe/it titles.
  • Validate security assumptions: disabled services cannot accrue usage, no negative/zero requests accepted.
• Test and commit

Test and commit

• Run npm run build, npm test, and npm run lint.
• Cover edge cases: zero requests, negative requests, float requests, oversized agent/serviceId, disabled service, saturation.
• Include the full npm test output in the PR description.

Example commit message

test: cover usage recording, accumulation, saturation, and disabled guard

Guidelines

• Minimum 95 percent test coverage for impacted modules.
• Clear, reviewer-focused documentation.
• Timeframe: 96 hours.

Community & contribution rewards

• 💬 Join the AgentPay community on Discord for questions, reviews, and faster merges: https://discord.gg/eXvRKkgcv
• ⭐ This is a GrantFox OSS / Official Campaign task and may be rewarded. When your PR is merged you'll be prompted to rate the project — if this issue and the maintainers helped you ship, we'd be grateful for a 5-star rating. Clear questions in Discord and tidy, well-tested PRs are the fastest path to a merge and a reward.

[YfengJ]

Hi maintainers, I would like to apply for this issue if it is still available.

If assigned, I will keep this test-focused: add src/usage.test.ts with supertest coverage for the usage write/read path, validation failures with requestId, disabled-service 409, repeated accumulation, unknown pair total: 0, and deterministic saturation near Number.MAX_SAFE_INTEGER. I will avoid production changes unless the tests expose a concrete bug, and will document any such fix clearly in the PR.

I will wait for maintainer or GrantFox assignment/confirmation before cloning, implementing, pushing, or opening a PR.

[gloskull]

Hello, I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process. My PR will be submitted in under 10hours.

[pq198363-ops]

/claim