This run specified Chrome and desktop default: testing for screene...em : homedepot.com - WebPageTest Result.
I also enabled lighthouse:
This caused lighthouse to be launched with the following command line parameters:
--form-factor desktop --screenEmulation.disabled --chrome-flags="--user-agent='Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML like Gecko) Chrome/117.0.0.0 Safari/537.36
See the lighthouse log here.
In the lighthouse json report, there is a section called configSettings that shows the conflict:
"formFactor": "desktop",
"screenEmulation": {
"mobile": true,
"width": 412,
"height": 823,
"deviceScaleFactor": 1.75,
"disabled": true
},
"emulatedUserAgent": "Mozilla/5.0 (Linux; Android 11; moto g power (2022)) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Mobile Safari/537.36",
I discovered this because I realized that lighthouse was referring to a mobile version of a web page where as WPT itself was referring to the desktop version.
I believe the lighthouse should be launched with:
--form-factor desktop --presets desktop
which would be fixed by changing the following lines of code: https://github.com/catchpoint/WebPageTest.agent/blob/465638a486fedde645e5e4c602fe160d8ca31332/internal/devtools_browser.py#L873.