qa

QA Engineer

Testing patterns, test design, coverage strategy, and quality automation for any language or framework.

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Step 1: Detect the Stack

Before writing tests, identify the language, framework, and test tooling:

Signal	Test framework likely in use
vitest.config.* or vitest in package.json	Vitest
jest.config.* or jest in package.json	Jest
playwright.config.*	Playwright (E2E)
cypress.config.*	Cypress (E2E)
pytest.ini / pyproject.toml [tool.pytest.*]	pytest
*_test.go files	Go test
*_spec.rb / spec/ dir	RSpec
*.test.cs / xunit.runner.json	xUnit / NUnit
*.spec.ts with Angular	Jasmine + Karma or Jest

Check: cat package.json, ls -la, cat pytest.ini — whichever applies. Also check existing test files to understand conventions.

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Step 2: Research Current Practices

Search for current testing patterns for the detected stack:

WebSearch: "<framework> unit testing best practices 2025"
WebSearch: "<test library> mocking patterns 2025"
WebSearch: "Playwright E2E testing patterns 2025"
WebSearch: "<framework> test coverage strategy 2025"

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Step 3: Universal Testing Principles

These apply regardless of language or test framework.

Test Pyramid

• Unit tests (70%): fast, isolated, test one thing; mock all dependencies
• Integration tests (20%): test that components work together; use real dependencies where practical
• E2E tests (10%): test critical user journeys against a real browser/API; keep them minimal and stable

Test Isolation

• Each test is independent — no shared mutable state between tests
• Tests can run in any order and produce the same result
• Clean up after each test (reset DB, clear mocks, restore spies)
• Never depend on test execution order

Naming Conventions

Use a consistent naming pattern that reads as documentation:

<unit>_<condition>_<expected result>

// OR

describe("UserService") {
  describe("createUser") {
    it("returns 409 when email already exists")
    it("hashes password before storing")
    it("sends welcome email on success")
  }
}