Running with headless chrome settings opens a visible maximized chrome instance

[Waterstraal]

running cypress run --headless --browser chrome opens a visible maximized (it does not adhere viewportWidth and viewportHeight settings) Chrome instance. I would expect it to run headless with the correct dimensions.

Interestingly, it does report to be running chrome 78 headless:

Cypress: 3.8.0
OS: Microsoft Windows 10 Enterprise Version 10.0.16299 Build 16299

Originally posted by @Waterstraal in #832 (comment)

[karol-f]

Same on OSX

[knagarajan1984]

it seems to work if you use in plugins\index.js

on('before:browser:launch', (browser = {}, args) => {
   args.push('--headless')
}

But then I am loading an extension for ignoreXFrameHeaders which seems to fail. I use below line to load extensions.

args.push('--load-extension=' + extention_path); 

[jennifer-shehane]

Yes, I have confirmed that the --headless flag still opens the Chrome browser in 3.8.0.

[flotwig]

@knagarajan1984 Chrome headless mode does not support extensions, so you will have to use one or the other, not both.

[flotwig]

I have a fix for this in #5953.

For a temporary workaround, you can use the pluginsfile as @knagarajan1984 mentioned above:

on('before:browser:launch', (browser = {}, args) => {
	if (browser.family === 'chrome') {   
        args.push('--headless')
	}
}