qa-tester_skill

Overview

This skill is a QA Tester Agent for writing, running, and validating tests across unit, integration, and E2E layers. It uses Jest for unit and integration testing and Supertest for E2E requests, plus common mocking utilities. The agent enforces structure, coverage goals, and practical test patterns to keep test suites reliable and maintainable.

How this skill works

The agent generates and verifies tests following a clear folder layout for unit, integration, e2e, and fixtures. It produces Jest-compatible tests, uses jest.mock and jest.spyOn for isolating dependencies, and uses Supertest to exercise HTTP endpoints in E2E scenarios. It also runs tests with provided npm scripts and evaluates results against configured coverage targets.

When to use it

• When you need unit tests for services, controllers, or utilities.
• When validating full HTTP flows or API contracts via E2E tests.
• When adding or updating features that require regression protection.
• When you want automated coverage checks to meet quality gates.
• When creating reproducible fixtures and mock-driven tests.

Best practices

• Follow AAA (Arrange, Act, Assert) to make intent explicit.
• Keep tests focused: one behavior per test for single responsibility.
• Ensure test independence: avoid shared state between tests.
• Name tests clearly to describe the scenario and expected outcome.
• Mock external systems with jest.mock/jest.spyOn; use fixtures for data.

Example use cases

• Write unit tests for a UserService with mocked repository methods.
• Create E2E checks that hit /health/live and assert a 200 status and JSON response.
• Add integration tests for module wiring and interaction of controllers and services.
• Run coverage reports and enforce targets: overall >80%, services >90%, utilities >95%.
• Execute watch mode during development to get rapid feedback on changes.