46fc6ca41a
* feat(types): improve typing of `.evaluate()` This is the start of the work to take the types from the `@types/puppeteer` repository and port them into our repo so we can ship our built-in types out the box. This change types the `evaluate` function properly. It takes a generic type which is the type of the function you're passing, and the arguments and the return that you get back from the `evaluate` call are typed correctly.
1.4 KiB
1.4 KiB
Home > puppeteer > ElementHandle > $$eval
ElementHandle.$$eval() method
This method runs document.querySelectorAll within the element and passes it as the first argument to pageFunction. If there's no element matching selector, the method throws an error.
If pageFunction returns a Promise, then frame.$$eval would wait for the promise to resolve and return its value.
Signature:
$$eval<ReturnType extends any>(selector: string, pageFunction: EvaluateFn | string, ...args: SerializableOrJSHandle[]): Promise<ReturnType>;
Parameters
| Parameter | Type | Description |
|---|---|---|
| selector | string | |
| pageFunction | EvaluateFn | string | |
| args | SerializableOrJSHandle[] |
Returns:
Promise<ReturnType>
Example 1
<div class="feed">
<div class="tweet">Hello!</div>
<div class="tweet">Hi!</div>
</div>
Example 2
const feedHandle = await page.$('.feed');
expect(await feedHandle.$$eval('.tweet', nodes => nodes.map(n => n.innerText)))
.toEqual(['Hello!', 'Hi!']);