azanir QA Pytest Writer
Purpose
Write pytest unit and integration tests from test case specifications. Transform structured test cases (from qa-testcase-from-docs, qa-manual-test-designer, or specs) into executable pytest code with fixtures, parametrization, markers, and conftest patterns.
Trigger Phrases
- "Write pytest tests for [module/function]"
- "Generate pytest unit tests from test cases"
- "Create pytest integration tests"
- "Add pytest tests with fixtures for [feature]"
- "Pytest parametrized tests for [function]"
- "Pytest tests with conftest fixtures"
- "Pytest async tests for [API handler]"
- "Pytest tests with mocking (monkeypatch/patch)"
Key Features
| Feature | Description |
|---|---|
| Fixtures | Scope: function, class, module, session; autouse, yield for teardown |
| @pytest.mark.parametrize | Data-driven tests with multiple input/output sets |
| Markers | skip, skipif, xfail, custom markers for categorization |
| conftest.py | Shared fixtures across test modules/directories |
| Plugin ecosystem | pytest-cov, pytest-xdist, pytest-asyncio, pytest-html, pytest-factoryboy |
| Assertion introspection | Rich failure output; plain assert statements |
Workflow
- Read test cases — From specs, requirements, or manual test designs
- Analyze Python code — Inspect module under test: functions, classes, dependencies
- Generate test files — Produce
test_{module}.pywith test functions - Add fixtures/conftest — Shared setup, teardown, parametrization
- Run — User runs
pytestto execute tests
Context7 MCP
Use Context7 MCP for current pytest documentation when:
- Fixture scope or parametrize syntax is uncertain
- Plugin APIs (pytest-asyncio, pytest-cov) need verification
- Marker or configuration options require up-to-date reference
Key Patterns
| Pattern | Usage |
|---|---|
test_ prefix |
Test functions: def test_something(): |
assert |
Plain assertions; no special API needed |
| Fixtures | def fixture_name(): with scope, autouse, yield |
@pytest.mark.parametrize |
Data-driven tests |
| Markers | @pytest.mark.skip, @pytest.mark.skipif, @pytest.mark.xfail |
| conftest.py | Shared fixtures in package/directory |
| monkeypatch | Built-in for patching attributes/env |
| tmp_path | Built-in temporary directory fixture |
| unittest.mock | patch, MagicMock for mocking |
Mocking
| Approach | Use Case |
|---|---|
| unittest.mock.patch | Patch modules, classes, functions |
| unittest.mock.MagicMock | Create mock objects with configurable behavior |
| pytest-mock (mocker) | mocker fixture wraps patch; cleaner syntax |
| monkeypatch | Built-in; patch attributes, env vars, sys.path |
Configuration
- pytest.ini — Legacy config (markers, addopts, testpaths)
- pyproject.toml — Modern config under
[tool.pytest.ini_options] - conftest.py — Fixtures, hooks, plugin config
See references/config.md for configuration patterns.
Plugin Recommendations
| Plugin | Purpose |
|---|---|
| pytest-cov | Code coverage reporting |
| pytest-xdist | Parallel test execution |
| pytest-asyncio | Async test support |
| pytest-html | HTML test reports |
| pytest-factoryboy | Factory fixtures for models |
File Naming
test_{module}.py— Preferred (e.g.,test_calculator.py)- Place in
tests/or colocated with source per project convention
Scope
Can do (autonomous):
- Generate pytest unit and integration tests from test case specs
- Add fixtures (function/class/module/session scope), conftest.py
- Use @pytest.mark.parametrize for data-driven tests
- Apply markers (skip, skipif, xfail, custom)
- Mock with patch, MagicMock, monkeypatch, pytest-mock
- Configure pytest.ini / pyproject.toml
- Call qa-diagram-generator for test flow diagrams if needed
Cannot do (requires confirmation):
- Change production code to satisfy tests
- Add tests for requirements not in source documents
- Override project-level pytest config without approval
Will not do (out of scope):
- Execute tests (user runs
pytest) - Write Playwright/Selenium E2E tests (use qa-playwright-ts-writer or Python E2E skills)
- Modify CI/CD pipelines
References
references/patterns.md— Fixtures, parametrize, conftest, async testing, mockingreferences/assertions.md— Assertion patterns: comparison, exceptions, warnings, approximatereferences/config.md— pyproject.toml, pytest.ini, conftest.py, markers, pluginsreferences/best-practices.md— Fixture scope, naming, organization, test isolation, coverage
Quality Checklist
- Tests match test case steps and expected results
- Fixtures are properly scoped (function vs session)
- No hardcoded secrets or sensitive data
- Assertions are specific (avoid only truthiness where value matters)
- Teardown via yield in fixtures where resources need cleanup
- File naming follows
test_{module}.pyconvention - Parametrize used for data-driven cases; markers for categorization
- Coverage targets considered if specified in requirements
Troubleshooting
| Symptom | Likely Cause | Fix |
|---|---|---|
| Fixture not found | Scope or conftest location | Ensure conftest.py in same dir or parent; check fixture scope |
| Parametrize id collision | Duplicate ids | Use ids parameter for unique test names |
| Tests pass individually, fail together | Shared mutable state | Use function-scoped fixtures; avoid module/session for mutable data |
| monkeypatch not persisting | Wrong target path | Patch where object is used (e.g., mymodule.func not builtins.func) |
| Async tests fail | Missing pytest-asyncio | Add @pytest.mark.asyncio; install pytest-asyncio |
| Coverage not collected | Plugin not configured | Add pytest-cov; run pytest --cov=src |
| Import errors in tests | Path/sys.path | Add conftest.py with sys.path or use pyproject.toml pythonpath |