Vue.js testing best practices, patterns, and common gotchas. Testing - Setting up test infrastructure for Vue 3 projects → See testing-vitest-recommended-for-vue - Tests keep breaking when refactoring component internals → See testing-component-blackbox-approach - Tests fail intermittently with race conditions → See testing-async-await-flushpromises - Composables using lifecycle hooks or inject fail to test → See testing-composables-helper-wrapper - Getting "injection Symbol(pinia) not found" errors in tests → See testing-pinia-store-setup - Components with async setup won't render in tests →…