---
trigger: model_decision
description: When you start working on a scenario, new methods or classes - do it unless user told you to do otherwise.
---
Every function and method must begin with a test. Core principle: tests prove that your implementation works as intended. As long as tests are not passing - you cannot claim that the scenario/class/method is implemented.
- Review current implementation you are about to start testing to learn methods, properties, fields etc. you can use.
- If actual implementation contradicts docstring - ask user what takes precedence, implementation or documentation.
- Review design documentation to if there is a guidance on how things shall be implemented.
- Write unit tests before implementing logic. When writing - do not write tests for RaiseNotImplemented; its there simply to fail your tests and remind you about properties/methods which need implementation. Write actual checks that shall pass, using docstrings and your design intent.
- Look into feature files to identify relevant scenarios explaining what we are doing docs/features and use them to guide your tests.
- Tests must test main success, border conditions, expected errors, handling of unexpected errors.
- Start with method-level tests, then go to API, then to integration.
- For integration: follow .windsurf/rules/do-not-mock-in-integration-tests.md
- Make the test fail, then implement logic to pass it.
- Use pytest for running tests.
- Do not mock unless absolutely necessary.
- **All tests must be placed in the `tests/` directory structure:**
- Unit tests: [tests/unit/]
- Integration tests: [tests/integration/]
- API tests: [tests/api/]
- End-to-end tests: [tests/e2e/]
- Service tests: [tests/services/]
- **Never place test files in the root directory of the repository**
