Add test coverage for usage rollups, agent aggregations, and CSV/JSON exports

[mikewheeleer]

Test the usage rollup, aggregation, and export endpoints

Description

src/index.ts exposes a family of read aggregations — GET /api/v1/agents, /agents/:agent/total, /agents/:agent/usage, /services/:serviceId/usage, /services/:serviceId/agents, /services/:serviceId/agents/top, plus usage/export.csv and usage/export.json. The CSV exporter even has custom quote-escaping. None of these are covered in src/health.test.ts. This issue adds coverage.

Requirements and context

• Repository scope: Agentpay-Org/Agentpay-backend only.
• Seed usage across multiple agents/services and assert each rollup returns correct totals and counts.
• Test top ordering (descending by total) and the limit clamp.
• Test the CSV exporter's escaping for values containing commas, quotes, and newlines, and the header row.
• Test the JSON export includes exportedAt and every (agent, serviceId, total) tuple.

Suggested execution

• Fork the repo and create a branch
• git checkout -b test/testing-16-rollups-exports
• Implement changes
  • Write comprehensive tests in: new src/aggregations.test.ts using supertest.
  • Write code in: no production change expected unless a real bug (e.g. an export escaping flaw) is found.
  • Add documentation: none beyond test descriptions.
  • Add clear test titles.
  • Validate security assumptions: CSV escaping prevents formula/injection via leading =/+ if relevant.
• Test and commit

Test and commit

• Run npm run build, npm test, and npm run lint.
• Cover edge cases: agent with no usage, service with one consumer, value needing CSV quoting.
• Include the full npm test output in the PR description.

Example commit message

test: cover usage rollups, aggregations, and csv/json exports

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.

[BojayL]

/claim

[BojayL]

/attempt #72

[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