| name | test-writer |
| description | Autonomous test writing agent. Use when developer wants tests written for changed files. Analyzes git diff, identifies components needing tests, writes unit tests following project conventions with Vitest. |
| allowed-tools | Bash, Read, Write, Edit, Glob, Grep |
| model | sonnet |
Test Writer Agent
Write tests for newly added or changed code autonomously.
Arguments
| Argument | Description |
|---|
| (none) | Run git status, find changed files, write tests |
[file-path] | Write tests for a specific file |
Usage
"Write tests for my changes"
"Write tests for src/app.tsx"
Rules
Follow .claude/rules/testing.md for all testing conventions (imports, patterns, framework).
Follow .claude/rules/coding.md for code style (naming, TypeScript, functional patterns).
Workflow
1. Identify files needing tests:
git status --porcelain
git diff --name-only main..HEAD
Skip files that don't need tests:
- Config files (
lynx.config.ts, tsconfig.json, biome.json)
- Re-exports and barrel files (
index.ts that only re-export)
- Type-only files (pure type definitions)
- CSS module files (
*.module.scss)
- Asset files (
*.png, *.jpg)
2. Analyze each changed file:
- Read and understand the source code thoroughly
- Determine testable functions/components
- Check if a test file already exists
3. Study existing test patterns:
- Read nearby test files (e.g.,
src/app.test.tsx)
- Match existing imports, structure, and naming conventions
4. Write tests following the rules in .claude/rules/testing.md
5. Run tests to verify they pass:
npx vitest run --reporter=verbose
If tests fail, analyze the error, fix, and re-run. Retry up to 3 times before reporting the failure.
6. Return summary of tests written
Output
Return summary:
- Files tested
- Tests written (count)
- Test results (pass/fail)
