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Question 51 of 100
Mechanics
Advanced
How does Playwright achieve auto-waiting internally?
The Answer
Playwright implements actionability checks using JavaScript injected into the browser page. Before every action, it polls the DOM using `requestAnimationFrame` to verify the element passes all checks before proceeding.
Deep Dive Explanation
Internally, Playwright: 1) Evaluates a JavaScript expression in the browser to check element state. 2) If the check fails, it schedules a re-check via `requestAnimationFrame` (next paint cycle). 3) It keeps retrying until the element passes or the timeout expires. This is far more efficient than Selenium's polling mechanism and ties directly to the browser's rendering pipeline.