| name | testing |
| description | Comprehensive testing strategies including TDD, unit, integration, E2E, and property-based testing. Ensures code quality and prevents regressions. Use when writing tests, implementing features test-first, or improving coverage. |
Testing
Testing strategies for code quality and regression prevention.
When to Use
- Implementing features (test-first)
- Fixing bugs (reproduce with test)
- Improving test coverage
- Refactoring safely
MCP Workflow
# 1. Find existing test patterns
serena.search_for_pattern("test|spec|describe", relative_path="test/")
# 2. Check test utilities
serena.get_symbols_overview(relative_path="test/support/")
# 3. Find similar tests
serena.find_symbol("*Test", depth=1, include_body=False)
# 4. Framework testing patterns
context7.get-library-docs("<testing-framework>", topic="testing")
Test Pyramid
/\
/E2E\ Few, slow, high confidence
/------\
/Integration\ Some, medium speed
/--------------\
/ Unit Tests \ Many, fast, focused
/------------------\
TDD Workflow
1. RED (Failing Test)
- Write minimal test for expected behavior
- Run test - verify it FAILS correctly
- Commit: "test: add failing test for [feature]"
2. GREEN (Pass It)
- Write minimal code to pass
- Run test - verify it PASSES
- Commit: "feat: implement [feature]"
3. REFACTOR
- Improve code structure
- Run tests - must still pass
- Commit: "refactor: improve [component]"
Test Structure (AAA)
test "should [behavior] when [condition]":
# Arrange - setup
input = create_test_input()
sut = create_system_under_test()
# Act - execute
result = sut.execute(input)
# Assert - verify
assert result.status == expected
Test Doubles
| Type | Purpose | Use When |
|---|
| Stub | Canned responses | Predictable input |
| Mock | Verify interactions | Verify calls |
| Spy | Record + real impl | Both needed |
| Fake | Working test impl | Real is slow |
Mock at boundaries: external APIs, databases, file systems.
Don't mock: private methods, value objects, simple utilities.
Bug Fix Pattern
1. REPRODUCE: Write failing test
2. VERIFY: Confirm it fails correctly
3. FIX: Implement minimal fix
4. CONFIRM: Test passes
5. EXPAND: Add edge case tests
Output Format
## Testing: [Scope]
| Category | Count | Status |
|----------|-------|--------|
| Unit | N | PASS/FAIL |
| Integration | M | PASS/FAIL |
### New Tests
1. `test_should_create_when_valid`
2. `test_should_reject_duplicate`
### Issues
- [failures or gaps]
Quality Checklist
