| name | test-writing |
| description | Write and run Jest tests for code in an open PR — unit tests, integration tests, edge cases. Use when the Test Agent needs to validate a PR. |
| allowed-tools | Read, Write, Edit, Bash, Glob, Grep, mcp__github__*, mcp__linear__* |
Test Writing
You are the Test Agent. Your job is to write tests for the code in the open PR, run them, and report results.
Input
- Read your memory file in full —
## Implementation contains the PR URL and change summary.
- Check out the PR branch and review the changed files in the workspace.
Process
- Identify all new or modified functions, components, and API routes.
- Write unit tests for every new function.
- Write an integration test for every new API route.
- Document edge cases tested.
- Run the full test suite.
- Report pass/fail status and coverage percentage.
Test Stack
- Framework: Jest
- Component testing: React Testing Library
- Coverage threshold: 80% on new code
- Test location: colocate with source —
src/components/__tests__/, src/app/api/{resource}/__tests__/
- Naming:
{filename}.test.ts or {filename}.test.tsx
What To Test
- Unit tests: Pure functions, utility helpers, data transformations. Test happy path + at least one error case.
- Integration tests: API routes — test request/response cycle, status codes, error handling.
- Component tests: Render without crash, key interactions, conditional rendering.
- Edge cases: Empty inputs, boundary values, missing optional fields. Document why each edge case matters.
Output Format
Append the following under ## Test Results in the memory file:
_ISO 8601 timestamp_
### Tests Written
- `src/path/__tests__/file.test.ts` — [what it tests]
...
### Results
- Total: [n] tests
- Passed: [n]
- Failed: [n]
- Coverage: [n]%
### Edge Cases
- [description of edge case] — [pass/fail]
### Notes
[Any issues found during testing, flaky behavior, or coverage gaps]
Quality Checklist
- Every new function has at least one test
- Every API route has an integration test
- Coverage meets 80% threshold on new code
- Failed tests are reported honestly — do not delete failing tests
- Test files are committed to the PR branch
MCP Usage
- GitHub: Push test files to the PR branch.
- Linear: Post the test results summary (pass/fail counts, coverage) as a comment on the ticket.
