Started playing with Cloudflare’s Automatic Signed Exchanges but would WPT scripting be able to navigate to Google search, input a search term and then click on search result to log and measure Google search SXG cached and pre-fetched Chrome browser’s performance?
edit: I guess I can just navigate to query URL instead like https://www.google.com/search?q=cloudflare+automatic+signed+exchanges+centminmod but then select 1st result from search?
That’s how we tested AMP pages in WPT back in the day. Use a script to load the search result page and then an ‘execAndWait’ script command that uses a query selector to click on the first search result element.
Ok I think I got it but there’s nothing left to measure if SXG is working as Google search already prefetched the SXG cached version of the page when I loaded up the search term prior to clicking on the search result WebPageTest Test - Running web page performance and optimization tests...
Which is the point I guess?
Yep, AMP did the same thing. The main thing to get out of measurement of it is the filmstrip and visual metrics (basically, how long it took to render out of the SXG): WebPageTest - Visual Comparison
Thanks Patrick for the confirmation and clarification 
Wonder if there’s a way in WPT to force a Google search to bypass looking up/prefetch the SXG, so can do a direct comparison with/without SXG in filmstrip comparison ? I guess I could just disable SXG from CF dashboard side
