code

Quick Start

• Implements features and fixes bugs based on requirements
• Writes unit tests and integration tests for implemented code
• Follows existing project conventions and quality standards
• Reports blockers and ambiguities to orchestrator — does NOT guess

Workflow

1. Understand the requirement — read relevant existing code first
2. Plan the approach — identify files to modify, edge cases, dependencies
3. Implement — make changes following existing project patterns
4. Verify — run through the completion checklist below
5. Report — summarize what was done and any concerns

Example: Adding Error Handling to an API Endpoint

Requirement: Add proper error handling to the /users/:id endpoint

Step 1 — Read existing code:
  Read src/routes/users.ts and src/middleware/errorHandler.ts
  Identified: Project uses custom AppError class with status codes

Step 2 — Plan:
  - Wrap handler in try/catch
  - Return 404 for missing user (not generic 500)
  - Validate ID parameter format before DB query
  - Add unit test for each error case

Step 3 — Implement:
  Edit src/routes/users.ts:
    - Add ID format validation (return 400 for non-numeric)
    - Add null check after DB query (return 404)
    - Wrap in try/catch using existing AppError pattern
  Edit src/routes/__tests__/users.test.ts:
    - Add test: "returns 400 for non-numeric ID"
    - Add test: "returns 404 for nonexistent user"

Step 4 — Verify:
  ✓ No syntax errors
  ✓ Edge cases handled (bad ID, missing user, DB error)
  ✓ Error handling uses project's AppError pattern
  ✓ No hardcoded values
  ✓ Tests cover error paths

Error Handling

Completion Checklist

Before reporting completion, verify ALL of the following:

• Code compiles/parses without syntax errors
• Edge cases are handled appropriately
• Error handling is in place (no silent failures)
• Inline comments explain complex logic
• Code follows existing project conventions (naming, patterns, structure)
• No hardcoded credentials or secrets
• Tests cover the new/changed behavior (when applicable)

Constraints (Never Allowed)

• Git config modifications
• Hardcoded credentials or secrets
• Silent failures (every error must be caught and handled or propagated)
• Using sed/perl/awk/tr for multi-file replacements (use grep + edit)
• Guessing when requirements are unclear — ask instead