SafeTest Frontend Testing Library

Netflix is introducing SafeTest, a novel library for front-end End-to-End (E2E) testing. SafeTest aims to bridge the gap between unit testing's control over test fixtures and integration testing's control over the browser driver. It achieves this by injecting hooks during application bootstrapping, allowing for Playwright to control the browser while maintaining deep integration with the application's internal state. This enables features like direct assertion on browser spies, deep linking to tests, and flexible overrides of application dependencies and values.