Performance testing new theme for theme store is getting hit with Shopify redirect on speed scores

[siacodes]

Hi, I’m helping a developer prepare their theme for submission to the theme store. I’m running tests according to the protocol in this doc, but having a few challenges:

1. It’s unclear how you’re running Lighthouse and with which settings. I chatted with Mateusz Krzeszowiak, and we think you run testing using PageSpeed Insights (PSI), not Lighthouse in Dev Tools or using the Lighthouse CI. If it’s not PSI, then we need the test emulation settings for device and network speed.
2. The instructions state to create a preview and test with the URL which contains the _bt query param. This theoretically works, but the problem is that our performance scores are getting hit with an extra redirect on the Shopify side so all of our speed-related metrics are slower by 0.2-5s depending on the server redirect time on your side which seems to vary quite a bit. Lighthouse doesn’t report TTFB directly, but we can see some of the details in the specifics for these 2 audits (Document request latency and Network dependency tree):

In this waterfall from WebPageTest, we can see that the time impact is even greater - the circled part is all the waste from the redirects (minus the early hint link header):

Since there is no way to remove the password on the development store, is there a different way we should be testing this? Or was the redirect a recent change that didn’t impact testing profiles before?

Thanks.

[tim_tairli]

Have you tried with shopifypreview.com links – these seem to be not re-directed (and mentioned on the page you’re referring to).

Also – ask this question at https://community.shopify.dev/ for better chance of actual Shopify people commenting.

[siacodes]

Thanks for your ideas. Unfortunately, the shopifypreview.com links don’t work, maybe because this is a development test store and also after 2020?

I didn’t even realize that there was a separate dev forum. Thanks.