Adding support for a noWaitLoadEvent config option

[mnemolyst]

Adding support for a gotoOptions config option, to be passed to Chromy, primarily for setting waitLoadEvent:false

[garris]

Thanks for the PR. What's the use case for this one?

[mnemolyst]

Hi -
Some websites hang on loading and never fire their "load" event, so chromy.goto() blocks until the script times out. Setting {"waitLoadEvent": false} in goto() prevents it from blocking.
Now that I think about it, given the multiple options Backstop provides for delaying screenshots, it might be okay to set waitLoadEvent: false by default.

[garris]

That sounds like a pretty big deal -- the load event not firing etc...

Are you not in a position to stabilize that?

[mnemolyst]

No, it's a Mindtouch site that I am only providing styling for, but have no access to content, backend, etc. There is one cross-origin asset load that hangs and prevents the site from finishing.

[garris]

Does this issue happen using puppeteer engine?

[mnemolyst]

It appears so. With Puppeteer I get the following:

Puppeteer encountered an error while running scenario "..."
TimeoutError: Navigation Timeout Exceeded: 30000ms exceeded

It's running headless so I can't see just what it's doing, but I believe it's the same error.
If I point it to another url, eventually I see in the console "Browser Console Log 0: JSHandle:BackstopTools have been installed.", which is generated by runPuppet.js on the line after "await page.goto()"
But running against the page that never emits the "load" event, I never see that line in the console.

[mnemolyst]

It does succeed with puppeteer if I add { waitUntil: 'networkidle2' } to the page.goto() call