tests/conftest.py sets os.environ["POSTGRES_HOST"] = "postgres-shared" at module level (before `from src.main import app`), commented "Use real postgres for integration tests". test_settings_loads_from_environment asserted settings.postgres_host == "test-postgres", a value grep confirms nothing in this suite has ever set — git log -p shows both the conftest line and this assertion originate in the same single commit and neither has changed since. Matched the assertion to the environment the suite actually runs under. Not a source change and not a claim that "postgres-shared" is the right fixture value for a suite this ticket also found is not actually hermetic where that value is concerned (see the 12 pre-existing DNS errors, tracked separately from this fix) — only that the assertion should test what the fixture sets, not an unset value.
Scheduler Tests
Comprehensive test suite for The Scheduler using pytest.
Test Structure
tests/
├── conftest.py # Shared fixtures and configuration
├── test_api.py # API endpoint tests
├── test_example_executor.py # Example executor tests
├── test_doc_sync_executor.py # Documentation sync executor tests
└── README.md # This file
Running Tests
Run all tests
docker exec scheduler pytest
Run with coverage report
docker exec scheduler pytest --cov=src --cov-report=term-missing
Run specific test file
docker exec scheduler pytest tests/test_api.py
Run specific test class
docker exec scheduler pytest tests/test_api.py::TestHealthEndpoint
Run specific test
docker exec scheduler pytest tests/test_api.py::TestHealthEndpoint::test_health_endpoint_returns_healthy
Run tests by marker
# Run only unit tests
docker exec scheduler pytest -m unit
# Run only API tests
docker exec scheduler pytest -m api
# Run only executor tests
docker exec scheduler pytest -m executor
# Run only fast tests (exclude slow)
docker exec scheduler pytest -m "not slow"
Run with verbose output
docker exec scheduler pytest -v
Run with detailed failure output
docker exec scheduler pytest -vv --tb=long
Stop on first failure
docker exec scheduler pytest -x
Test Markers
Tests are organized with pytest markers:
@pytest.mark.unit- Fast unit tests with no external dependencies@pytest.mark.integration- Integration tests (may use database)@pytest.mark.api- API endpoint tests@pytest.mark.executor- Task executor tests@pytest.mark.slow- Tests that take a while to run
Coverage Reports
After running tests with coverage:
- Terminal: Shows missing lines in terminal output
- HTML: Open
htmlcov/index.htmlin browser for detailed report - JSON: Machine-readable coverage data in
coverage.json
View HTML coverage report:
# From host machine
open /home/jpmschweitzer/docker-data/scheduler/htmlcov/index.html
Writing New Tests
Test File Naming
- Test files must start with
test_ - Place in
tests/directory - Use descriptive names:
test_<module_name>.py
Test Function Naming
- Test functions must start with
test_ - Use descriptive names:
test_<what_is_being_tested>
Using Fixtures
Fixtures are defined in conftest.py:
def test_something(test_settings, auth_headers):
# Use fixtures as function parameters
assert test_settings.app_name == "Test Scheduler"
Adding Markers
@pytest.mark.unit
@pytest.mark.api
def test_health_endpoint(client):
response = client.get("/health")
assert response.status_code == 200
Async Tests
@pytest.mark.asyncio
async def test_async_function():
result = await some_async_function()
assert result is not None
Mocking
from unittest.mock import patch, MagicMock
def test_with_mock():
with patch('module.function') as mock_func:
mock_func.return_value = "mocked"
result = call_function_that_uses_it()
assert result == "mocked"
Continuous Integration
These tests are designed to run in CI pipelines:
# Example GitHub Actions
- name: Run tests
run: |
docker exec scheduler pytest --cov=src --cov-report=xml
docker exec scheduler pytest --cov=src --cov-report=html
Test Database
Tests use mocked database connections by default. For integration tests that require a real database:
- Set up a test database
- Use
POSTGRES_DB=test_schedulerenvironment variable - Run migrations before tests
- Clean up after tests
Troubleshooting
Tests fail with "ModuleNotFoundError"
# Install test dependencies
docker exec scheduler /venv/bin/pip install -r requirements.txt
Tests fail with database errors
- Tests use mocked connections by default
- Check that mocks are properly set up in conftest.py
- For integration tests, ensure test database exists
Coverage not working
# Reinstall pytest-cov
docker exec scheduler /venv/bin/pip install --upgrade pytest-cov
Best Practices
- Fast by default: Unit tests should be fast (<1s each)
- Isolated: Tests should not depend on each other
- Descriptive: Test names should clearly describe what they test
- Single assertion: Test one thing per test when possible
- Use fixtures: Reuse common setup via fixtures
- Mock external deps: Don't hit real databases/APIs in unit tests
- Mark appropriately: Use markers to categorize tests
Current Coverage
Run this to see current coverage:
docker exec scheduler pytest --cov=src --cov-report=term
Target: 80%+ code coverage for critical paths