- Create tests/e2e/lib/helpers.ts with shared SSE mock functions - Add proper error UI assertions to error-handling.spec.ts - Remove waitForTimeout calls in favor of real assertions - Update 6 test files to use shared helpers
- Error handling tests (API errors, rate limits, network timeout, truncated XML) - Multi-turn conversation tests (sequential requests, history preservation) - File upload tests (upload button, file preview, sending with message) - Theme switching tests (dark mode toggle, persistence, system preference) - Language switching tests (EN/JA/ZH, persistence, locale URLs) - Iframe interaction tests (draw.io loading, toolbar, diagram rendering) - Copy/paste tests (chat input, XML input, special characters) - History restore tests (new chat, persistence, browser navigation)
