Testing Engineering

Overview

Domain specialist for testing strategies, test frameworks, TDD/BDD methodologies, and quality assurance. Expertise includes unit testing, integration testing, end-to-end testing, test doubles (mocks, stubs, fakes), test pyramid, coverage strategies, and test quality assessment.

Trigger Words

• testing, test, unit test, integration test, e2e test
• TDD, BDD, test-driven, behavior-driven
• mock, stub, fake, test double
• coverage, test coverage
• PHPUnit, Jest, PyTest, RSpec, Cypress, Playwright
• test pyramid, test smells, test quality

Detection

Framework Detection

PHP:

• PHPUnit (phpunit.xml, tests/ directory, use PHPUnit\Framework\TestCase)
• Pest (Pest.php, use PHPUnit\Framework\TestCase with test() functions)
• Codeception (codeception.yml, _support/ directory)
• Behat/Gherkin (.feature files, FeatureContext.php)

JavaScript/TypeScript:

• Jest (__tests__/, *.test.js, *.spec.js, jest.config.js)
• Mocha (describe(), it(), before(), after())
• Vitest (vitest.config.ts, import { test, expect } from 'vitest')
• Jasmine (describe(), it(), spyOn())
• Cucumber.js (.feature files)
• Cypress (cypress/, cy. commands)
• Playwright (playwright.config.ts, test(), page.)
• Puppeteer (puppeteer imports, page.evaluate())

Python:

• PyTest (conftest.py, def test_, @pytest.fixture)
• unittest (unittest.TestCase, self.assertEqual())
• Nose2 (nose2.cfg)
• Behave (.feature files, behave command)
• Locust (locustfile.py, @task)
• Robot Framework (.robot files)

Ruby:

• RSpec (spec/ directory, describe(), it(), expect().to)
• Minitest (test/ directory, class Test* < Minitest::Test)
• Cucumber (.feature files, Given/When/Then)

Go:

• testing (_test.go, func Test*, testing.T)
• testify (assert.Equal(), testify/suite)
• ginkgo (Describe(), It())

Java:

• JUnit (@Test, org.junit.jupiter.api.Test)
• TestNG (@Test, org.testng.annotations.Test)
• Mockito (Mockito.mock(), when().thenReturn())

C#:

• NUnit ([Test], Assert.AreEqual())
• xUnit ([Fact], [Theory], Assert.Equal())
• Moq (Mock<T>(), .Setup())

Mode Detection

Write Mode (Progressive Guidance)

Trigger: mode=write or no explicit testing task

Load Progressive Files:

1. TEST-PYRAMID.md - Understand testing strategy
2. AAA-PATTERNS.md - Learn test structure
3. UNIT-TESTING.md - Unit testing fundamentals
4. TEST-FRAMEWORKS.md - Framework-specific guidance

Behavior:

• Provide concise examples
• Focus on getting started quickly
• Progressive complexity (simple → advanced)
• Framework-specific guidance

Review Mode (Exhaustive Checklists)

Trigger: mode=review, "review tests", "audit tests", "check test quality", "assess testing"

Load Review Files:

1. TEST-QUALITY.md - Quality assessment checklist
2. TEST-SMELLS.md - Test anti-patterns detection
3. COVERAGE.md - Coverage metrics and thresholds
4. COVERAGE-STRATEGIES.md - Coverage strategy assessment

Behavior:

• Exhaustive review checklists
• Identify test smells
• Coverage analysis
• Quality metrics
• Gap identification

Skill Loading Strategy

Initial Load

function loadTestingEngineeringSkill(context) {
    const mode = context.mode || 'write';

    if (mode === 'review') {
        // Load review-mode files
        loadProgressive([
            'TEST-QUALITY.md',
            'TEST-SMELLS.md',
            'COVERAGE.md',
            'COVERAGE-STRATEGIES.md'
        ]);
    } else {
        // Load write-mode files
        loadProgressive([
            'TEST-PYRAMID.md',
            'AAA-PATTERNS.md',
            'UNIT-TESTING.md',
            'TEST-FRAMEWORKS.md'
        ]);
    }

    // Always load core concepts based on query keywords
    if (context.query.match(/tdd|test-driven/i)) {
        load('TDD.md');
    }

    if (context.query.match(/bdd|behavior-driven|cucumber|behave|gherkin/i)) {
        load('BDD.md');
    }

    if (context.query.match(/mock|stub|fake|test-double/i)) {
        loadProgressive(['TEST-DOUBLES.md', 'MOCKING.md']);
    }

    if (context.query.match(/coverage/i)) {
        loadProgressive(['COVERAGE.md', 'COVERAGE-STRATEGIES.md']);
    }

    if (context.query.match(/integration/i)) {
        load('INTEGRATION-TESTING.md');
    }

    if (context.query.match(/e2e|end-to-end|cypress|playwright|puppeteer/i)) {
        load('E2E-TESTING.md');
    }

    if (context.query.match(/unit/i)) {
        load('UNIT-TESTING.md');
    }
}

Progressive Disclosure Files

Philosophies (Progressive)

1. TDD.md - Test-Driven Development methodology
2. BDD.md - Behavior-Driven Development methodology
3. TEST-PYRAMID.md - Testing strategy pyramid (unit > integration > e2e)

Frameworks (Progressive)

4. TEST-FRAMEWORKS.md - Framework detection and setup (PHPUnit, Jest, PyTest, RSpec)
5. FRAMEWORK-PATTERNS.md - Common framework patterns

Writing Tests (Progressive)

6. AAA-PATTERNS.md - Arrange-Act-Assert test structure
7. MOCKING.md - Mocking frameworks and best practices
8. TEST-DOUBLES.md - Test doubles (mocks, stubs, fakes, spies)

Test Types (Progressive)

9. UNIT-TESTING.md - Unit testing fundamentals
10. INTEGRATION-TESTING.md - Integration testing strategies
11. E2E-TESTING.md - End-to-end testing with Cypress/Playwright

Coverage & Quality (Progressive)

12. COVERAGE.md - Coverage metrics and thresholds
13. COVERAGE-STRATEGIES.md - Coverage strategy and goals
14. TEST-QUALITY.md - Test quality assessment checklist
15. TEST-SMELLS.md - Test anti-patterns and refactoring

Quick Reference

Test Pyramid

        E2E Tests
       (Small %)
       ↑ Low value
       ↓ Slow
    Integration Tests
      (Medium %)
      ↑ Medium value
      ↓ Medium speed
      Unit Tests
     (Largest %)
     ↑ High value
     ↓ Fast

Testing Layers

Coverage Goals

Common Test Frameworks

Core Concepts

AAA Pattern

// Arrange - Setup test data
const user = { id: 1, name: 'John' };
const expected = 'John';

// Act - Execute code under test
const result = getUserById(user.id);

// Assert - Verify results
expect(result.name).toBe(expected);

Test Doubles

• Stub - Pre-programmed responses
• Mock - Expectations verification
• Fake - Working implementation (in-memory)
• Spy - Record method calls

TDD Cycle

1. Red - Write failing test
2. Green - Make test pass (minimal code)
3. Refactor - Improve code

Common Testing Commands

PHP

# PHPUnit
./vendor/bin/phpunit
./vendor/bin/phpunit --filter testUserLogin

# Pest
./vendor/bin/pest
./vendor/bin/pest --filter testUserLogin

# Codeception
vendor/bin/codecept run
vendor/bin/codecept run functional

# Behat
vendor/bin/behat

JavaScript/TypeScript

# Jest
npm test
npm test -- --watch
npm test -- --coverage

# Vitest
npm run test
npm run test:watch

# Cypress
npx cypress open
npx cypress run

# Playwright
npx playwright test
npx playwright test --headed

Python

# PyTest
pytest
pytest --cov=src
pytest -k test_user_login

# unittest
python -m unittest
python -m unittest discover

# Behave
behave

Ruby

# RSpec
rspec
rspec --format documentation
rspec --only-failures

# Minitest
rails test
rails test:units

# Cucumber
cucumber
cucumber features/login.feature

When to Use This Skill

Use When:

• User mentions testing, tests, TDD, BDD
• Reviewing test quality or coverage
• Setting up test framework
• Writing unit/integration/e2e tests
• Refactoring test code
• Assessing test strategy

Do Not Use For:

• Code refactoring (use software-engineering)
• Performance optimization (use performance-engineering)
• Database queries (use database-engineering)
• Security vulnerabilities (use secops-engineering)

Internal References

This skill does NOT reference other skills. All testing concepts are self-contained.

File Structure

~/.config/opencode/skill/testing-engineering/
├── SKILL.md (this file)
├── philosophies/
│   ├── TDD.md
│   ├── BDD.md
│   └── TEST-PYRAMID.md
├── frameworks/
│   ├── TEST-FRAMEWORKS.md
│   └── FRAMEWORK-PATTERNS.md
├── patterns/
│   ├── AAA-PATTERNS.md
│   ├── MOCKING.md
│   └── TEST-DOUBLES.md
├── types/
│   ├── UNIT-TESTING.md
│   ├── INTEGRATION-TESTING.md
│   └── E2E-TESTING.md
└── quality/
    ├── COVERAGE.md
    ├── COVERAGE-STRATEGIES.md
    ├── TEST-QUALITY.md
    └── TEST-SMELLS.md