Feature request: possibility to handle `page.on('request',...)` in several places

Use case:

I am developing a testkit which does page.on('request', ...) in order to intercept specific requests. The problem: A user can write another interceptor which handles specific requests and calls request.continue() for all the rest (as this is mandatory for requests that we do not handle).

As a result, only the first request handler “wins” (the second handler will receive “request is already handled!” error.)

A possible solution: Today we must have request.continue() for every request that we do not want to handle. What if puppeteer will do it by default, for requests that it finds as “unhandled”. In this case, each handler will only take care of its own interceptors, and will do nothing about the rest of requests.

[b5l]

Puppeteer could implement a public API to check whether a request is already handled or not. There is already the _interceptionHandled property on the Request class, we would essentially just need a getter for that. Any thoughts? @aslushnikov

[aslushnikov]

What if puppeteer will do it by default, for requests that it finds as “unhandled”.

@yanivefraim With the currently-exposed API, it’s unclear when the request is “unhandled”. Consider an artificial example of “network throttling” using request interception:

page.on('request', request => {
  setTimeout(request.continue.bind(request), 1000);
});

Since Puppeteer gives away control over the request to the client, client might continue them anytime in future as they require. They might even drop the request on the floor without continuing to simulate server stalling. So from Puppeteer’s stand point, we can’t auto-continue requests since it will break many valid usecases.

However, it looks like your testkit introduces certain conventions over request interception, e.g. “request should be either synchronously aborted, or it will be auto-continued” (i might got it wrong). In this case, you can auto-continue all requests in a subsequent microtask:

page.on('request', request => Promise.resolve().then(() => request.continue()).catch(e => {}));

Let me know if I understand you correctly and if it helps.