Avoid flaky end-to-end tests due to poorly hydrated Frontends with Playwright’s toPass()
AI Summary
This video addresses the common issue of flaky tests in end-to-end testing or synthetic monitoring using Playwright, attributing many of these issues to poor hydration patterns in the frontend environment rather than the tests themselves. It explains poor hydration as a scenario where UI elements appear ready but are not fully functional because the JavaScript required hasn’t loaded yet, causing failures when Playwright interacts with these elements too quickly. The video demonstrates this with a simple demo site and a Playwright test that fails due to such hydration delays.
The ideal solution is to fix the frontend to disable UI elements until they are fully functional, but this is often not feasible due to legacy code or organizational boundaries. Instead, the video suggests using Playwright’s “to pass” method to implement a retry mechanism that repeatedly attempts actions or assertions until they succeed, making tests more stable without relying on arbitrary delays.
It also highlights configuration options for the “to pass” method such as retry intervals and overall timeout to tailor the approach to specific needs. Finally, it recommends validating test stability by repeatedly running tests and encourages addressing hydration issues in the frontend for best results. The presenter invites viewers to share feedback and promises more tips on testing and monitoring in future videos.