One thing that could be nice for us to try out is the
https://github.com/w3c/longtasks API
Long Tasks is a new real user measurement (RUM) performance API to enable applications to measure responsiveness. It enables detecting presence of “long tasks” that monopolize the UI thread for extended periods of time and block other critical tasks from being executed - e.g. reacting to user input.
It is enabled by default in Chrome 58.
| Subject | Repo | Branch | Lines +/- | |
|---|---|---|---|---|
| Observe long tasks and report them in the console | mediawiki/extensions/PerformanceInspector | master | +17 -1 |
Seems like adding long tasks can break Firefox if we aren't careful: https://bugzilla.mozilla.org/show_bug.cgi?id=1398477
Experimenting locally, I can trigger it when opening VE on a cold cache, but not with a warm cache.
We can add it to PerformanceInspector's startup module, but that doesn't run early enough to catch things that have to do with our page startup. Still good to find issues in things people interact with after the initial pageload.
Change 377984 had a related patch set uploaded (by Gilles; owner: Gilles):
[mediawiki/extensions/PerformanceInspector@master] Observe long tasks and report them in the console
Change 377984 abandoned by Imarlier:
Observe long tasks and report them in the console
Reason:
Implemented in Chrome devtools already