[py] Remove logging API for non-Chromium browsers

[cgoldberg]

User description

🔗 Related Issues

Fixes #15588
Fixes #15589
Fixes #15587
Fixes #15586

💥 What does this PR do?

This PR changes the logging API in the Python bindings so it only works on Chromium based browsers (Chrome/Edge), as discussed in: #15588

It removes the related methods from the selenium.webdriver.remote.webdriver.WebDriver class and adds them to selenium.webdriver.chromium/webdriver.WebDriver.

Relevant tests have been updated so the are expected failures on all non-Chromium browsers.

This will bring the Python bindings in line with other language bindings where this has already been removed from most browsers.

🔄 Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)

---

PR Type

Bug fix, Enhancement

[qodo-merge-pro]

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[titusfortner]

So I looked deeper at Ruby Selenium code, and we have a MixIn that allows users to call this method from Chromium. So maybe we just want to move this to Chromium driver class and not delete it entirely (sorry for my earlier mixup).

[cgoldberg]

OK, I'll update this PR in a little while (and also fix the linting error)

[cgoldberg]

It should be all set now... I updated the PR description also.

I moved the logging methods to the Chromium WebDriver class, so it works in Chrome/Edge. I also adjusted the tests to be expected failures on all browsers except Chrome/Edge.

... just waiting for CI to run.

[cia2154]

Am I correct in understanding that this PR broke programs that call get_log from webdriver.Remote?
As GraemeWatt mentions, is the only solution to just call driver.execute(Command.GET_LOG, {"type": ""})["value"]?

The following code works fine in 4.31.0, but doesn't work in 4.32.0.

from selenium import webdriver
from selenium.webdriver.remote.command import Command

options = webdriver.ChromeOptions()
options.set_capability('goog:loggingPrefs', {'performance': 'ALL'})

driver = webdriver.Remote(
    command_executor='http://localhost:4444/wd/hub',
    options = options
)

try:
    driver.get('http://example.com/')
    # AttributeError: 'WebDriver' object has no attribute 'get_log' in 4.32.0
    print(driver.get_log('performance'))

    # This code works with both versions
    #print(driver.execute(Command.GET_LOG, {"type": "performance"})["value"])

except Exception as e:
    raise e
finally:
    driver.quit()

[cgoldberg]

@cia2154 yes, that is correct. I will look into restoring it for remote chromedriver/edgedriver.

[titusfortner]

@cgoldberg add those methods to here:

selenium/py/selenium/webdriver/chromium/remote_connection.py

Line 45 in 9b48eb1

def _remote_commands(self, vendor_prefix):

[cgoldberg]

@titusfortner I tried to implement this, but I can't find a good way to add get_log and get_log_types methods to the base WebDriver class (for remote) so only Chrome/Edge browsers can access them.

I don't see how adding those methods to _remote_commands helps with that.

I think we would need a pretty big restructuring of the class hierarchy to allow Chromium specific methods on a webdriver.Remote instance.

Maybe I'm missing something?

[cgoldberg]

Thinking about this some more... The only solution I can think of is to move the get_log and get_log_types methods back to the parent WebDriver class, and also add them to subclasses for non-Chromium browsers... and when they are called from a subclass, just raise NotImplementedError.

The methods on the base WebDriver class would need to check which browser it's using when those methods are called and raise NotImplementedError if the driver isn't Chrome or Edge.

It's kind of ugly, but this would allow the logging API to be used for Chrome, Edge, and Remote drivers, and give a reasonable error when called from a local or remote driver that is not Chrome or Edge.

[titusfortner]

You don't need to throw a not implemented error. There are a bunch of chromium specific features like casting that work with Remote driver.

This isn't a great way to do it to reference subclasses this way, but it avoids mixins which Python people don't like:
https://github.com/SeleniumHQ/selenium/blob/trunk/py/selenium/webdriver/remote/webdriver.py#L122

Literally just add those methods to the list above, and webdriver will add the commands to remote sessions that have that browser name

[cgoldberg]

There are a bunch of chromium specific features like casting that work with Remote driver.

None of the casting methods (like get_sink, start_tab_mirroring, stop_casting) work on Remote webdrivers (because of the same issue I am running into).

Literally just add those methods to the list above, and webdriver will add the commands to remote sessions that have that browser name

It doesn't. _remote_commands is just a mapping of command names to endpoints. For eaxmple, it contains this:

"launchApp": ("POST", "/session/$sessionId/chromium/launch_app")

There is a method on chromium.WebDriver called launch_app that references this command. However, you can't call launch_app on a Remote instance... it doesn't exist.

So to use any of the commands listed in _remote_commands, you have to implement a method that calls the command. Where do I add that method? Do you have an example of a method you can call on a Remote instance that only works for Chromium browsers? I can't find any.