Run a lighthouse test against the current browser session

[M-Z]

I can see the comment "Run a lighthouse test against the current browser session"
But, after launching the agent with the browser GUI, I can see the browser closes and a new one spawns just for LH. Which loses the cookies/storage/etc. for my tests.
I applied a quick fix (don't know if this is the right approach here) that might help

wptagent.py
L#129

self.task['running_lighthouse'] = False
     if self.task['run'] == 1 and not self.task['cached'] and \
         self.job['warmup'] <= 0 and \
         self.task['error'] is None and \
         'lighthouse' in self.job and self.job['lighthouse']:
                 if 'page_result' not in self.task or \
                     self.task['page_result'] is None or \
                     self.task['page_result'] == 0 or \
                     self.task['page_result'] == 99999:
                         self.task['running_lighthouse'] = True
              self.run_single_test()
              self.wpt.get_bodies(self.task)
              elapsed = monotonic() - start
              logging.debug('Test run time: %0.3f sec', elapsed)

L#191

if browser is not None:
            browser.prepare(self.job, self.task)
            browser.launch(self.job, self.task)
            try:
                browser.run_task(self.task)

                if self.task['running_lighthouse']:
                    self.task['lighthouse_log'] = \
                        'Lighthouse testing is not supported with this browser.'
                    try:
                        browser.run_lighthouse_test(self.task)
                    except Exception:
                        logging.exception('Error running lighthouse test')
                    if self.task['lighthouse_log']:
                        try:
                            log_file = os.path.join(self.task['dir'], 'lighthouse.log.gz')
                            with gzip.open(log_file, GZIP_TEXT, 7) as f_out:
                                f_out.write(self.task['lighthouse_log'])
                        except Exception:
                            logging.exception('Error compressing lighthouse log')

devtools_browser.py
L#54
Removed the ret = self.devtools.wait_for_available(self.CONNECT_TIME_LIMIT)
and made it just connect once to the dev tools interface and not wait/reconnect to the devtools
L#267

if not self.task['running_lighthouse']:
        self.task = None

[pmeenan]

I don't understand exactly what you are trying to do. You can't re-use a browser session across a WPT test and a Lighthouse test.

Lighthouse makes 3-4 passes across a page measuring different things and is expecting to be in full control and starting from a clean slate. If you need to specify additional headers or cookies it needs to be done explicitly.

[M-Z]

I'm trying to access a page behind auth. For WPT, setCookie is enough. But for LH, the page gets redirected to the login page probably due to some JS code.
Currently, I tried two approaches that worked to some extent:

1. (Explained above) Is to keep the browser open (with all cookies/data set already) and run LH on a new tab.
2. Tried sending command Network.setCookie in run_lighthouse_test but the devtools weren't connecting (due to the new browser window for LH?). So I had to remove self.devtools.wait_for_available(self.CONNECT_TIME_LIMIT) and connect to a new Devtools instance to inject cookies.

Is there another "right" way to inject cookies into the browser for LH to work with WPT other than --extra-headers flag?

Thanks for your time!

[pmeenan]

The easiest way with lighthouse is to set the cookies as explicit HTTP headers (custom headers in the advanced tab "Cookie: xxxxx"). Lighthouse supports the additional headers.

[M-Z]

This doesn't work for me in both WPT and LH. So I was trying to do something like setCookie for LH as well.

[imkalvin]

Hi @pmeenan & @M-Z ,

I managed to get this work with #420

Could you help to take a look whether it meets the overall design of WPT+LH?

[M-Z]

Hi @imkalvin ,

I'm currently just using a local patch for my test agents.
Injecting this snippet in devtools_browser.py after this line

if 'cookies' in self.task:
    for cookie in self.task['cookies']:
        self.devtools.send_command('Network.setCookie', cookie)

I also changed this method and removed the running_lighthouse if statement.

I have this patch running thousands of tests daily for the last 6 months and I didn't see anything going wrong for me.