window.chrome object not available in "headless" mode

Perhaps this is not the correct place for this (I’ve also filed this bug: https://bugs.chromium.org/p/chromium/issues/detail?id=806333 but I wasn’t sure where to dig in.

I’m finding that when I run my Nightwatch tests with Chrome in “headless” mode, that certain odd tests are failing consistently that pass when run “not in headless” mode. Upon digging in, it appears that the window.chrome and/or chrome objects are not available/present to webpages loaded in “headless” mode.

This is a problem for us because some of the things we test for are dependent on whether or not a User’s browser as window.chrome && window.chrome.webstore, which should both be truthy in any version of Chrome, headless or not I would think.

Is this expected behavior? Anything that can be done?

[aslushnikov]

This is a problem for us because some of the things we test for are dependent on whether or not a User’s browser as window.chrome && window.chrome.webstore, which should both be truthy in any version of Chrome, headless or not I would think.

@newhouse the absence of window.chrome is an implication of headless architecture.

Chromium consists of layers:

A few things on this diagram are important:

• content layer is the API to build “browsers”. So if you’re building a browser, you’re embedding content.
• Chromium is a browser and a typical content embedder. A lot of Chromium functionality, e.g. extensions and window.chrome, lives in the chrome layer
• headless is, in fact, another browser - a different content embedder. Since extensions are in the chrome layer, they’re naturally missing in the headless browser.

Hope this helps.

[JoelEinbinder]

Look into how puppeteer does evaluateOnNewDocument: https://github.com/GoogleChrome/puppeteer/blob/master/lib/Page.js#L658