The change to curl_param_value_generators.py warrants a brief
explanation. Stream permission changes now generate a notification
message. Our curl example test for removing a reaction comes after
the two tests for updating the stream permission changes, thus the
hardcoded message ID in that test needs to be incremented by 2 to
account for the two notification messages that now come before it.
This is a part of #20289.
do_make_stream_web_public and do_change_stream_invite_only seem
to contain very similar logic that could just live inside the
do_change_stream_permission function that handles all permission
changes in one place.
We now complain if a test author sends a stream message
that does not result in the sender getting a
UserMessage row for the message.
This is basically 100% equivalent to complaining that
the author failed to subscribe the sender to the stream
as part of the test setup, as far as I can tell, so the
AssertionError instructs the author to subscribe the
sender to the stream.
We exempt bots from this check, although it is
plausible we should only exempt the system bots like
the notification bot.
I considered auto-subscribing the sender to the stream,
but that can be a little more expensive than the
current check, and we generally want test setup to be
explicit.
If there is some legitimate way than a subscribed human
sender can't get a UserMessage, then we probably want
an explicit test for that, or we may want to change the
backend to just write a UserMessage row in that
hypothetical situation.
For most tests, including almost all the ones fixed
here, the author just wants their test setup to
realistically reflect normal operation, and often devs
may not realize that Cordelia is not subscribed to
Denmark or not realize that Hamlet is not subscribed to
Scotland.
Some of us don't remember our Shakespeare from high
school, and our stream subscriptions don't even
necessarily reflect which countries the Bard placed his
characters in.
There may also be some legitimate use case where an
author wants to simulate sending a message to an
unsubscribed stream, but for those edge cases, they can
always set allow_unsubscribed_sender to True.
For web-public streams, clients can access full topic history
without being authenticated. They only need to additionally
send "streams:web-public" narrow with their request like all
the other web-public queries.