Testing automation

File-specific instructions for writing unit tests.

The examples in this library are intended for inspiration—you are encouraged to adjust them to be more specific to your projects, languages, and team processes.
For community-contributed examples of custom instructions for specific languages and scenarios, see the Awesome GitHub Copilot Customizations repository.
You can apply custom instructions across different scopes, depending on the platform or IDE where you are creating them. For more information, see "AUTOTITLE."

This example shows a path-specific python-tests.instructions.md file that applies only to Python test files in your repository, using the applyTo field. For more information about path-specific instructions files, see AUTOTITLE.

---
applyTo: "tests/**/*.py"
---

When writing Python tests:

## Test Structure Essentials
- Use pytest as the primary testing framework
- Follow AAA pattern: Arrange, Act, Assert
- Write descriptive test names that explain the behavior being tested
- Keep tests focused on one specific behavior

## Key Testing Practices
- Use pytest fixtures for setup and teardown
- Mock external dependencies (databases, APIs, file operations)
- Use parameterized tests for testing multiple similar scenarios
- Test edge cases and error conditions, not just happy paths

## Example Test Pattern
```python
import pytest
from unittest.mock import Mock, patch

class TestUserService:
    @pytest.fixture
    def user_service(self):
        return UserService()

    @pytest.mark.parametrize("invalid_email", ["", "invalid", "@test.com"])
    def test_should_reject_invalid_emails(self, user_service, invalid_email):
        with pytest.raises(ValueError, match="Invalid email"):
            user_service.create_user({"email": invalid_email})

    @patch('src.user_service.email_validator')
    def test_should_handle_validation_failure(self, mock_validator, user_service):
        mock_validator.validate.side_effect = ConnectionError()

        with pytest.raises(ConnectionError):
            user_service.create_user({"email": "[email protected]"})
```