Improve navigation

Navigation is hard. Make sure the following navigation scenarios work properly:

• page.navigate('not-a-url') should return false
• page.navigate('https://expired.badssl.com/') should return false
• page.navigate('http://example.com/non-existing-page') should return false
• page.navigate('http://example.com') with no internet should return false
• page.navigate('data:text/html,hello') should return true
• Page’s navigation via inner javascript’s window.location.href = 'http://example.com' should be reported to puppeteer, probably via the Navigated event.

All of this should be also applicable to frame navigation in #4

[paulirish]

it could return the fetch response object for the main resource

[aslushnikov]

So the issue with returning true/false is that it’s hard to decide what is a success and what is a failure. For example, navigating to a 404 page might be a valid scenario, since a lot of websites have their own custom-made 404’s.

How about:

• we consider navigation failed if there’s a navigation timeout or an interstitial
• anything else returns a status code for the main resource

This should address both @JoelEinbinder and @paulirish concerns. What do you guys think?