Starting around March 6, setViewportSize stopped changing the resolution. We run private instances, but I’ve tested on your site and see the same issue.
Here are the results:
https://www.webpagetest.org/result/170310_QW_11VK/
Here’s the script:
setViewportSize 375 667
navigate http://whatismyscreenresolution.net/
Searching has turned up similar issues. The solution was to put a tab between the height and width but I don’t believe that’s the current issue. The script text field doesn’t seem to take tabs, and when I click the yellow ‘script’ above the “Re-run the test” button it seem to have automatically added the tab.
setviewportSize is still broken but we’ve found a solution for the API call.
Our dev team had been calling the API with …runtest.php?..&width=375&height=667. After searching through runtest.php I decided to change ‘width’ and ‘height’ to ‘browser_width’ and ‘browser_height’. It works for us now. I’m not sure if it was broken before and never should have accepted height&width, or if they’re being overwritten by the browser_height/browser_width variables.
I am also experiencing the same issue. It stopped changing the browser size. I use runtest.php POST call. Adding width and height or browser_width and browser_height did not fix the issue. It keep runs the test in default window size no matter what the width/height are provided or passing the dimensions from setViewportSize.