| name | testing-reflex-state |
| description | Generates pytest unit tests for Reflex.dev state logic — event handlers, computed vars, substates, and mocked external dependencies. Use when the user asks to write, scaffold, or review tests for a Reflex State class. Do NOT use for Playwright integration tests or UI component rendering tests. |
Testing Reflex State
Reflex State is a plain Python class — no browser or runtime needed.
Test it directly with pytest and pytest-asyncio.
Setup
pip install pytest pytest-asyncio pytest-cov
pyproject.toml:
[tool.pytest.ini_options]
testpaths = ["tests/unit"]
asyncio_mode = "auto"
python_files = ["test_*.py"]
File layout
tests/unit/
├── conftest.py
├── test_base_state.py
└── test_project_state.py
Patterns
Base vars → test defaults directly
Sync handlers → call on instance, assert result
Async handlers → await, assert is_loading is False after
Streaming handlers → consume with async for
Computed vars → mutate base vars, assert property
Substates → instantiate subclass independently
External I/O → unittest.mock.patch at myapp.state.*
Background tasks → patch __aenter__/__aexit__
See references/PATTERNS.md for full code examples.
See references/FIXTURES.md for shared fixture setup.
Decision: which pattern to use?
Sync handler? → Test directly, no async
Async handler? → Use await, check loading flag resets
Handler bound to Radix UI component? → Add str AND list[str] test cases
Handler calls API/DB? → Mock with AsyncMock, test both success and failure
Background task (@rx.event(background=True))? → Patch context manager
Run
pytest tests/unit/ -v --cov=myapp/state --cov-report=term-missing
pytest tests/unit/test_project_state.py -v
pytest tests/unit/ -x
