Write good tests and define integration tests
Test Design: Definitions, Trade-offs, and Best Practices
Context
You are tasked with designing a reliable test suite for a small service. This service is typical of a modern application, comprising a REST API, a database, and interactions with a third-party dependency (e.g., a payment gateway).
Tasks
- Define the layers of automated testing:
- Unit tests
- Integration tests
- End-to-end (E2E) tests
- Explain the purpose and scope of integration testing (what to include/avoid, boundaries, and when to use it).
- Discuss isolation vs. realism in tests and how to balance them.
- Describe test fixtures (what they are, types, and good practices).
- Explain determinism in tests and how to ensure it.
- List common causes of flaky tests and how to prevent/fix them.
- Provide concrete examples throughout.
AI interview prep
Core dilemma
Balancing comprehensive test coverage and high confidence in system behavior against the practical constraints of test speed, maintainability, and infrastructure cost, especially when dealing with external dependencies.
3 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Write good tests and define integration tests
Test Design: Definitions, Trade-offs, and Best Practices
Context
You are tasked with designing a reliable test suite for a small service. This service is typical of a modern application, comprising a REST API, a database, and interactions with a third-party dependency (e.g., a payment gateway).
Tasks
- Define the layers of automated testing:
- Unit tests
- Integration tests
- End-to-end (E2E) tests
- Explain the purpose and scope of integration testing (what to include/avoid, boundaries, and when to use it).
- Discuss isolation vs. realism in tests and how to balance them.
- Describe test fixtures (what they are, types, and good practices).
- Explain determinism in tests and how to ensure it.
- List common causes of flaky tests and how to prevent/fix them.
- Provide concrete examples throughout.