| name | scaffold_tests |
| description | Generates unit and regression test files for existing code. Creates "Happy Path", "Edge Case", and "Error" test stubs. |
Scaffold Tests
Use this skill to automatically generate test suites for your code, ensuring functionality is locked in.
Inputs
- Target File: The source code specific to test.
- Test Runner: (Optional) Jest, Pytest, etc.
Tooling Strategy
- Use
view_file to analyze the source code.
- Use
write_to_file to create the test file.
Workflow
1. Context Analysis
- Target: Analyze the open file or the specified module (e.g.,
utils.py, auth.js).
- Framework Detection: Determine the project's test runner (Jest, PyTest, Mocha, Unittest). If none, suggest the most lightweight option suitable for the user's legacy hardware.
2. Test Strategy
Plan the test coverage:
- Unit Tests: Isolated tests for individual functions/classes.
- Regression Tests: Tests that ensure specific bugs (fixes) don't reappear.
- Naming Convention: Standardize names (e.g.,
[filename].test.js or test_[filename].py).
3. Generation (The "Safety Net")
Write the test file with three specific sections:
- Happy Path: Standard inputs produce standard outputs (The "It works" check).
- Edge Cases: Nulls, empty strings, zeros, huge numbers (The "Robustness" check).
- Error Handling: Invalid inputs trigger the expected error messages (The "Security" check).
4. Output
- Save the file to a
tests/ directory or alongside the source code (based on project convention).
- Prompt the user to run them using
/run_tests.
Advanced Testing Patterns
- Test-Driven Development (TDD): Write failing test FIRST, implement minimal code to pass, refactor after green. Never write production code without a failing test.
- Behavior-Driven Testing: Test behavior, not implementation details. Focus on public APIs and business requirements. Use descriptive test names that describe the behavior.
- Factory Pattern: When scaffolding tests, create data factory functions (e.g.,
getMockUser(overrides)) that provide sensible defaults but allow tests to override specific properties. This keeps tests DRY and maintainable.
- Mocking Strategies: Use factory functions to mock entire modules or specific hooks when scaffolding tests to isolate the unit under test.
