allow --force-device-scale-factor=1 as setting in seleniumbase

[svenstehle]

Hi, I want to run my tests on GitHub Actions CI and I am writing the tests locally on macos. The retina display that I am using consistently doubles width and height.

I addressed this by crudely monkeypatching get_new_driver of BaseCase:

from selenium import webdriver
from seleniumbase import BaseCase


class ComponentsTest(BaseCase):
    def get_new_driver(self, *args, **kwargs):
        """ This method overrides get_new_driver() from BaseCase. """
        options = webdriver.ChromeOptions()
        options.add_argument("--force-device-scale-factor=1")    # fix macos retina displays
        if self.headless:
            options.add_argument("--headless")
        driver = webdriver.Chrome(options=options)
        width = 1920
        height = 1080
        driver.set_window_size(width, height)
        print('Window size', driver.get_window_size())
        return driver

But this is a very crude solution and it broke on my second test case when I used self.click. How can I cleanly enable any google chrome browser option that I can pass to selenium.webdriver in that way, also work in seleniumbase?

I found custom_settings.py but I don't know if that is the right place?

Using those works to set the width and height:

CHROME_START_WIDTH = 1920
CHROME_START_HEIGHT = 1080
HEADLESS_START_WIDTH = 1920
HEADLESS_START_HEIGHT = 1080

Can I somehow set force-device-scale-factor=1 with seleniumbase --chromium-arg and can you point me to the correct syntax? I can't figure it out.

Help appreciated, thank you :)

[svenstehle]

I figured it out for one argument: --chromium-arg="force-device-scale-factor=1" works as I want it to and fixes the width and height to the specified values in the custom_settings.py. Is this the only way?

And: what is the correct syntax if I want to provide more than just one additional argument? Something like:
--chromium-arg="force-device-scale-factor=1 disable-gpu" ?

[mdmintz]

Hi @svenstehle
Use --chromium-arg=ARG (Add a Chromium arg for Chrome/Edge, comma-separated.)
It's a comma-separated list of chromium args.
Eg pytest --chromium-arg="ARG1=1,ARG2=2" (no spaces - use quotes around everything)

Using a custom_settings file can help you override settings set in settings.py:
Eg https://github.com/seleniumbase/SeleniumBase/blob/master/examples/custom_settings.py
pytest --settings=custom_settings.py

[svenstehle]

@mdmintz Thanks for the quick response!

I tinkered with it some more and I can confirm that

pytest tests --settings-file=tests/custom_settings.py --chromium-arg="force-device-scale-factor=1,headless"

works like you said :) Scaling factor is set AND the browser starts headless.

Is that already in the documentation somewhere? I could not find examples besides the comment next to the option:

--chromium-arg=ARG # (Add a Chromium arg for Chrome/Edge, comma-separated.)

Would you be open to extend the documentation with an exact syntax example for this option?

[mdmintz]

Hi @svenstehle That's in the documentation: https://github.com/seleniumbase/SeleniumBase/blob/master/help_docs/customizing_test_runs.md

Click on "Options" near the top of the main ReadMe file.

And --headless already exists as a built-in SeleniumBase option.

pytest tests --headless --settings-file=tests/custom_settings.py --chromium-arg="force-device-scale-factor=1"

[svenstehle]

Maybe I misunderstand. I cannot find an example in the ReadMe like the one you showed me.

Eg pytest --chromium-arg="ARG1=1,ARG2=2" (no spaces - use quotes around everything)

[mdmintz]

It's right here:

[svenstehle]

It's right here:

I don't want to appear cheeky or rude here. I think the helpful and concise example that you have given in this issue thread could improve the documentation right there.

Suggestion, from your example:

--chromium-arg="ARG1=1,ARG2=2" # (Add a Chromium arg for Chrome/Edge, comma-separated, no spaces.)

I am open to create a PR for this.

[mdmintz]

@svenstehle I just made some changes:

30eafb0

--chromium-arg="ARG=N,ARG2"  # (Set Chromium args, ","-separated, no spaces.)
--firefox-arg="ARG=N,ARG2"  # (Set Firefox args, comma-separated, no spaces.)

[svenstehle]

Awesome, that looks good! I think that will help a few newbies like me a lot. Thanks :)

[nakodavati]

if i pass args like this is this correct ? --chromium-arg="--no-sandbox,--disable-dev-shm-usage" will it take these

[mdmintz]

@nakodavati Yes. (Note that both those args are already set by SeleniumBase if running on Linux.)

[nakodavati]

@mdmintz how can i make sure it is already set by seleniumBase , inside container while executing tests i am proving these options as command line argument

[mdmintz]

@nakodavati In a test, use self.driver.options.arguments to see the options used when the browser was launched.