## Testing Best Practices

### DO

- **Use factories**: Instead of manual object creation
- **One assertion per test**: Keep tests focused
- **Descriptive test names**: `test_user_cannot_delete_others_post`
- **Test edge cases**: Empty inputs, None values, boundary conditions
- **Mock external services**: Don't depend on external APIs
- **Use fixtures**: Eliminate duplication
- **Test permissions**: Ensure authorization works
- **Keep tests fast**: Use `--reuse-db` and `--nomigrations`

### DON'T

- **Don't test Django internals**: Trust Django to work
- **Don't test third-party code**: Trust libraries to work
- **Don't ignore failing tests**: All tests must pass
- **Don't make tests dependent**: Tests should run in any order
- **Don't over-mock**: Mock only external dependencies
- **Don't test private methods**: Test public interface
- **Don't use production database**: Always use test database