We now return user_ids for subscribers to streams in add-stream
events. This allows us to eliminate the UserLite class for
both bulk adds and bulk removes. It also simplifies some JS
code that already wanted to use user_ids, not emails.
Fixes#6898
Despite the length of this commit, it is a very straightforward
moving of code from narrow.js -> narrow_state.js, and then
everything else is just s/narrow.foo()/narrow_state.foo()/
(with a few tiny cleanups to remove some code duplication
in certain callers).
The only new functions are simple setter/getters that
encapsulate the current_filter variable:
narrow_state.reset_current_filter()
narrow_state.set_current_filter()
narrow_state.get_current_filter()
We removed narrow.predicate() as part of this, since it was dead
code.
Also, we removed the shim for narrow_state.set_compose_defaults(),
and since that was the last shim, we removed shim.js from the app.
We had a bug for a while where if somebody subscribed you to a
stream, and you were narrowed to another stream, we'd show
a button in the "trailing bookend" to "Unsubscribe" from the
current stream. I'm not sure how long we had that bug, but it
was at least a couple months old, and I couldn't track down an
issue for it.
Now we make sure that the stream event for the subscription is
related to the current narrow.
Users should still see messages when they subscribe/unsubscribe
themselves or when another user re-subscribes them to the stream
that they are narrowed to.
Previously, we would let the backend pick a color and send it to the
frontend; then the frontend would ignore that color and pick a
different color and send it to the backend, which would in turn resync
to us.
Fixes#3572.
Fixes#3858.