test-engineer

Test Engineer Standards

Testing Rules

• All new logic must include unit and integration tests.
• Simulated or test data must be clearly marked and never promoted to production.
• All tests must pass in CI pipelines before deployment.
• Code coverage should exceed 85% on business logic modules.
• Regression tests must be defined for all high-impact updates.
• Log test outcomes in separate test logs, not production logs.

Test Structure

<!-- PLATFORM: Android -->

Android

• Prefer unit tests over instrumented tests when business logic is isolated.
• Use MockK for mocking. Use Espresso for UI testing.
• Name test functions with backticks: @Test fun when input is X, expect Y() {}
• Use Given/When/Then (Arrange-Act-Assert) structure. <!-- END PLATFORM: Android -->

<!-- PLATFORM: iOS -->

iOS

• Use XCTest for unit and integration tests. Use XCUITest for UI testing.
• Use protocol-based fakes over mocking frameworks where possible.
• Name tests descriptively: test_scenario_expectedOutcome.
• Use Given/When/Then (Arrange-Act-Assert) structure. <!-- END PLATFORM: iOS -->

<!-- PLATFORM: Web -->

Web

• Use Jest or Vitest for unit tests. Use Playwright or Cypress for E2E.
• Name tests descriptively: it('should do X when Y').
• Mock external dependencies; prefer dependency injection over module mocks.
• Use Given/When/Then (Arrange-Act-Assert) structure. <!-- END PLATFORM: Web -->

<!-- PLATFORM: Backend -->

Backend

• Use the language's standard test framework.
• Name tests descriptively — the name should explain the scenario and expected outcome.
• Use the project's standard mocking library for test doubles.
• Use Given/When/Then (Arrange-Act-Assert) structure. <!-- END PLATFORM: Backend -->

Verification

• Diff behavior between main and your changes when relevant.
• Ask yourself: "Would a staff engineer approve this?"
• Run tests, check logs, demonstrate correctness.

Error Handling Design

• Error handling logic must be designed using test-first principles.
• Retry logic must include exponential backoff and failure limits.