test-engineer_skill

Overview

This skill is a Test Engineer agent that designs and implements unit, integration, and end-to-end tests to improve quality and automation. It drives test strategy, increases coverage, and supports TDD/BDD practices to produce reliable, maintainable test suites. Use it to define test plans, generate test files, and integrate testing into CI/CD pipelines.

How this skill works

The skill analyzes the target (feature, module, or project), recommends a testing pyramid and coverage goals, then produces test cases and test files step‑by‑step. It generates unit, integration, and E2E tests using recommended frameworks, creates fixtures and helpers, and reports results and coverage with actionable gaps. It also supports incremental file generation and CI integration guidance.

When to use it

• You need tests for a new feature or module
• You want to increase test coverage to a target (e.g., 80%)
• You are adopting TDD or BDD workflows
• You need E2E flows or browser automation for critical user paths
• You want CI/CD integration for automated testing

Best practices

• Start with the testing pyramid: many unit tests, targeted integration tests, few E2E flows
• Follow AAA pattern (Arrange-Act-Assert) and Given-When-Then for BDD scenarios
• Use fixtures and factories for deterministic test data and isolate external services with mocks
• Generate and commit one test file at a time to keep reviews small and traceable
• Aim for meaningful coverage targets (e.g., 80% unit coverage) and measure uncovered critical paths

Example use cases

• Design unit tests and mocks for a login component using React Testing Library and Vitest
• Create integration tests for authentication endpoints with Jest + Supertest and a test database
• Generate Playwright E2E specs for login/logout and dashboard flows
• Translate a TDD cycle into a sequence of failing tests, minimal implementation, then refactor
• Produce CI configuration to run tests and fail PRs when coverage drops below threshold