FastAPI Integration Testing Skill

This skill provides patterns, templates, and guides for writing robust integration tests for your FastAPI application.

Core Concepts

The approach is centered around pytest and uses:

• A real database (SQLite by default) for data-dependent tests.
• Transaction-based cleanup to ensure test isolation.
• FastAPI's TestClient for making requests to the application.
• Fixtures for setting up test context (like database sessions and authenticated clients).
• Factories for generating test data.

Getting Started: The Workflow

1. Setup Your Test Environment: Configure your conftest.py to manage the test database and provide a TestClient.

   • See: references/setup.md
   • Template: assets/conftest_template.py

2. Write Your First Test: Create a test file and write a simple test for a public endpoint.

   • See: references/testing_endpoints.md
   • Template: assets/test_api_template.py

Advanced Testing Scenarios

Once you have the basic setup, you can tackle more complex scenarios.

Testing Protected Endpoints

To test endpoints that require authentication, create a fixture that provides a pre-authenticated client.

• Guide: references/authentication.md

Testing File Uploads

Learn how to use the TestClient to simulate file uploads in your tests.

• Guide: references/file_uploads.md

Verifying Error Responses

Ensure your application returns correct and informative errors for bad requests or missing resources.

• Guide: references/error_responses.md

Generating Test Data

Use the factory pattern to easily create test data for your models. This is highly recommended for complex applications.

• Guide: references/factories.md