test-master

Complete Vitest 4.0 Playwright 1.56 MSW 2.x testing system with 2025 best practices and Windows/Git Bash support. PROACTIVELY activate for: (1) ANY testing task (unit/integration/E2E/visual), (2) Browser Mode testing (Vitest 4.0 stable release Oct 2025), (3) Visual regression testing (toMatchScreenshot), (4) Playwright AI Test Agents (planner/generator/healer), (5) Test annotation and metadata (Vitest 3.2+), (6) Mutation testing for quality assurance, (7) Test creation and scaffolding, (8) Playwright Traces debugging with titlePath, (9) Coverage analysis and optimization, (10) MSW 2.x mock management with happy-path-first patterns, (11) Role-based locator patterns, (12) CI/CD test setup, (13) Multi-project test architecture, (14) Line-number filtering, (15) Windows/Git Bash cross-platform testing. Provides: Vitest 4.0 features (stable browser mode, visual regression with toMatchScreenshot, Playwright trace integration, toBeInViewport matcher), Playwright 1.56 features (AI agents - Planner/Generator/Healer, VS Code 1.105+ integration, titlePath hierarchy, Debian 13), MSW 2.x best practices (Fetch API primitives, domain-based handlers), Windows/Git Bash path conversion awareness and shell detection, mutation testing capabilities, intelligent test running, auto-scaffolding with boilerplate, coverage gap analysis, advanced snapshot management, parallel execution optimization, and comprehensive cross-platform 2025-compliant test infrastructure. Ensures production-ready testing with latest patterns across all platforms including Windows Command Prompt, PowerShell, Git Bash, macOS, and Linux.