Use firefox headless mode

Hi,

Since FF55 it’s possible to use the -headless flag. I would be nice to have it added to the options passed to firefox or add a FirefoxHeadlessBrowser.

Cheers

[keithamus]

In the meantime it is quite simple to set this up. Here is the minimum config options you need:

module.exports = config => {
  config.set({
    browsers: ['FirefoxHeadless'],
    customLaunchers: {
      FirefoxHeadless: {
        base: 'Firefox',
        flags: [ '-headless' ],
      },
    },
  })
}

[jscharett]

My apologies, user error. Forgot to add require('karma-firefox-launcher') to the karma plugins.