Implement page.on('requestfinished')

[ankur22]

Feature Description

page.on('requestfinished') should be called when the request is successfully sent and a response from the website under test (WuT) is received. The response can be errors such as 404/500 etc.

When implementing page.on('request') and page.on('response') it became apparent that some of the methods on the request and response objects didn't behave the same as in Playwright. However, to overcome the shortfalls (1, 2) in page.on('request') a user should work with page.on('response') and to overcome the shortfall in that, we should implement both page.on('requestfailed') and page.on('requestfinished').

Suggested Solution (optional)

The implementation should be fairly trivial and these two PRs should help with the implementation:

1. Add page.on('request') #4290
2. Add page.on('response') #4296

The call to the handle should be done from onLoadingFinished.

Already existing or connected issues / PRs (optional)

Connected to: #4234