puppeteer.webworker.evaluate.md

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WebWorker.evaluate() method

If the function passed to the worker.evaluate returns a Promise, then worker.evaluate would wait for the promise to resolve and return its value. If the function passed to the worker.evaluate returns a non-serializable value, then worker.evaluate resolves to undefined. DevTools Protocol also supports transferring some additional values that are not serializable by JSON: -0, NaN, Infinity, -Infinity, and bigint literals. Shortcut for await worker.executionContext()).evaluate(pageFunction, ...args).

Signature:

evaluate<ReturnType extends any>(pageFunction: Function | string, ...args: any[]): Promise<ReturnType>;

Parameters

Parameter	Type	Description
pageFunction	Function | string	Function to be evaluated in the worker context.
args	any[]	Arguments to pass to pageFunction.

Returns:

Promise<ReturnType>

Promise which resolves to the return value of pageFunction.