How can we script scrolling on the page?

Some of the pages I test happen to kick in the image load among other things when I scroll down. However WPT video shows only the top front.

In particular, this affects retail sites where the catalog loads.

I was thinking of exec window.scrollBy but was wondering if there are other alternatives that folks here use to script scrolling down

That’s pretty much what I have done any time I needed to do it. The thing that usually gets a bit tricky is to get WPT to continue the measurement while you’re doing the scrolling (usually a combination of combineSteps and execAndWait) because it wasn’t originally built to record video of arbitrary page interactions.