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 mostly moves code, and it also removes some unnecessary
coupling to stream_data.js. The topic_data code purely
works in the stream_id space, so there's no need to set up
actual stream data for it.
Steve Howell
Steve Howell