From the EWS bubbles you can't tell if a bot is a build-only bot, or a build-and-test bot. All this time I've been assuming that GTK was running tests, and that assumption was wrong.
After fix in https://bugs.webkit.org/show_bug.cgi?id=176332 EWS now displays whether it did run tests or not. You will need to click on each bubble to see this information.
I think that this is relatively easy to solve from UI standpoint - we just need a description line at the top of a bubble. It should also tell what OS version is being tested.
What's a bit of a challenge is keeping this information up to date - EWS has no concept of bot registration. So we either need to add such a concept, or to manually maintain a description file for EWS bots.
Fixed in https://bugs.webkit.org/show_bug.cgi?id=201253
EWS bubbles now shows a symbol indicating if the bubble is for build, test or both.