Senior QA Skill for Claude

Senior QA Engineer

Test automation, coverage analysis, and quality assurance patterns for React and Next.js applications. Generates Jest + React Testing Library unit test stubs, analyzes Istanbul/LCOV coverage for gaps, and scaffolds Playwright E2E suites for App Router and Pages Router projects.

Core Capabilities

• Unit test generation — scan React/TypeScript components and emit Jest + RTL stubs (render, interaction, state, optional jest-axe a11y).
• Coverage analysis — parse Istanbul/LCOV reports, identify gaps by severity, flag critical business-logic paths, and emit text/HTML/JSON recommendations.
• E2E scaffolding — detect Next.js routes (dynamic segments, route groups, auth pages) and generate Playwright specs, Page Object Models, fixtures, and config.
• Test strategy — the testing pyramid, coverage targets by code type, and test organization patterns.
• Automation patterns — Page Object Model, data factories, MSW mocking, fixtures, and custom render utilities.
• Quality practices — testable code design, AAA structure, test isolation, flaky-test elimination, and quality metrics.

When to Use

• Setting up unit tests for new or existing React components.
• Improving test coverage or preparing for release.
• Setting up Playwright E2E tests for a Next.js project.
• Configuring Jest thresholds or improving overall test quality.

Clarify First

Before generating tests, confirm these inputs. If any is unknown or vague, ASK — do not assume:

• [ ] Test layer — unit (Jest+RTL) vs E2E (Playwright) (selects test_suite_generator vs e2e_test_scaffolder)
• [ ] Source path — the components or Next.js routes to generate tests from (the scaffolder's input)
• [ ] Coverage focus — happy path only vs interaction/state/a11y (jest-axe) (sets which test stubs are emitted)

Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the artifact.

Tools

| Tool | Purpose | Command |

|------|---------|---------|

| test_suite_generator.py | Generate Jest + RTL test stubs from React components | python scripts/test_suite_generator.py src/components/ --output __tests__/ |

| coverage_analyzer.py | Analyze Istanbul/LCOV coverage and report gaps | python scripts/coverage_analyzer.py coverage/coverage-final.json --threshold 80 |

| e2e_test_scaffolder.py | Scaffold Playwright E2E tests from Next.js routes | python scripts/e2e_test_scaffolder.py src/app/ --output e2e/ |

References

Load the reference that matches the task — keep this file lean and pull detail on demand:

• references/qa-workflows-and-tools.md — quick start, the three tool overviews with sample output, the unit-test/coverage/E2E workflows, common pattern snippets (RTL queries, async, MSW, Playwright locators, jest thresholds), common commands, troubleshooting table, and success criteria. Read when running a workflow.
• references/tool-cli-reference.md — full flag tables, examples, output formats, and generated artifacts for all three scripts. Read before running the scripts.
• references/testing_strategies.md — the testing pyramid, testing types, coverage targets and thresholds, and test organization patterns. Read when designing test strategy.
• references/test_automation_patterns.md — Page Object Model, data factories, fixture management, mocking strategies (MSW), and custom test utilities. Read when writing test code.
• references/qa_best_practices.md — writing testable code, naming conventions, AAA pattern, test isolation, flaky-test debugging, and quality metrics. Read when improving test quality.

Scope & Limitations

This skill covers:

• Unit test stub generation for React/TypeScript functional and class components using Jest and React Testing Library.
• Coverage analysis and gap identification from Istanbul JSON and LCOV report formats.
• E2E test scaffolding for Next.js App Router and Pages Router projects using Playwright.
• Accessibility test generation via jest-axe integration.

This skill does NOT cover:

• Backend API testing (see senior-backend for Express/Node.js testing patterns).
• Performance or load testing (see senior-devops for infrastructure and performance tooling).
• Visual regression testing or screenshot comparison workflows.
• Mobile-native testing (React Native, Flutter) -- this skill targets web browser-based testing only.

Integration Points

| Skill | Integration | Data Flow |

|-------|-------------|-----------|

| senior-frontend | Generated test stubs align with component patterns from the frontend skill | Frontend components --> test_suite_generator.py --> test files |

| senior-fullstack | Code quality analyzer consumes the same coverage reports produced here | coverage_analyzer.py output --> fullstack quality dashboard |

| senior-devops | E2E test scaffolder generates CI-ready Playwright configs that plug into DevOps pipelines | e2e_test_scaffolder.py --> playwright.config.ts --> GitHub Actions workflow |

| code-reviewer | Coverage gaps feed directly into code review checklists for untested changes | coverage_analyzer.py gaps --> review checklist items |

| tdd-guide | TDD workflow references this skill's test generator for initial red-phase stub creation | TDD cycle --> test_suite_generator.py --scan-only --> write tests --> implement |

| qa-browser-automation | Page Object Models generated here are consumed by the browser automation skill for advanced E2E scenarios | e2e_test_scaffolder.py --include-pom --> POM classes --> browser automation flows |