AFAIK I should this never fail, hence the blueslip.error line. But it
is failing in practice when rendering user groups after looking them
up by ID, and the error handling should definitely be softer.
This run_test helper sets up a convention that allows
us to give really short tracebacks for errors, and
eventually we can have more control over running
individual tests. (The latter goal has some
complications, since we often intentionally leak
setup in tests.)
This fixes the user groups UI to follow the Zulip standard mechanisms
(using the appropriate server_events system to update all browsers
properly). It also, as a side effect, fixes#8692, since it
eliminates the weird behavior of trying to re-insert a user group
after reformatting it in the frontend.
Thanks to Tarun Kumar for preliminary work on this.
Tim Abbott
Rohitt Vashishtha
Steve Howell
Tarun Kumar
Cynthia Lin
Jerry Zhang