Support async/await syntax in JS functions

[nesk]

Currently, it is impossible to use await in a JS function because the function isn't defined as async. Making all the JS functions async by default is not a good option because some Puppeteer's events could one day require a return value.

A good option would be to add a chaining method to return an async JS function:

JsFunction::create("console.log(await 'Hello world!')")->async()

The above function creation would generate the following JS code:

return async function () {
    var page = global.puphpeteerResources['a-unique-id-to-the-resource'];
    console.log(await page.content())
};

Important: the documentation must be updated.

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Method chaining should probably be implemented before dealing with this issue.

[JoelEinbinder]

It is extremely unlikely that puppeteer will require a return value for events. For the same reason as you, we wouldn’t want marking functions as async to drastically change the behavior.

[nesk]

Oh, that's some good news! However, I think I will stick with this approach since its closer to the way JS works (the fact that functions are sync by default).

Thank you for the info!