Fix windowSize option in Firefox in Javascript

[rodmcnew]

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Hi guys.

"--window-size" is for screenshots only in Firefox, not the size of the Firefox window itself.
"--width" and "--height" are the proper way to set the dimensions of a Firefox window from the CLI.

Proof:

firefox -h | grep screenshot
 --screenshot [<path>] Save screenshot to <path> or in working directory.
 --window-size width[,height] Width and optionally height of screenshot.

Works (after my change):

firefox --width=1920 --height=1080

Doesn't work (before my change):

firefox --window-size=1920,1080

[bradharms]

EDIT: What @rodmcnew said.

[pertamaks]

`opt_fox = Selenium::WebDriver::Firefox::Options.new
opt_fox.add_argument('--width=1024') #your preferred size
opt_fox.add_argument('--height=700') #your preferred size

Capybara.register_driver :firefox do |app|
Capybara::Selenium::Driver.new(app, browser: :firefox, options: opt_fox)
end`

to work with Capybara.
Will leave it here, maybe someone in need,
or, maybe someone can make it better,

[codebymikey]

This doesn't work for me in headless mode for the nodejs driver, setting it through an environment variable does though.

process.env.MOZ_HEADLESS_WIDTH = 1280;
process.env.MOZ_HEADLESS_HEIGHT = 1024;

References:
mozilla/geckodriver#1354 (comment)
https://github.com/mozilla/gecko-dev/blob/d3860ab2859aafd9eb1551e0f9035c5779bc38f1/testing/geckodriver/doc/Testing.md