The previous phrasing used incorrect terminology (E.g. "stream
members", not "stream subscribers", which is really confusing given
that we have a "member" role which is also relevant in this text).
This reduces the complexity of our dependency graph.
It also makes sub_store.get parallel to message_store.get.
For both you pass in the relevant id to get the
full validated object.
This change should make live-update code less brittle,
or at least less cumbersome.
Instead of having to re-compute calculated fields for
every change to a stream message, we now just compute
the fields right before we render stream settings UI.
This is mostly a pure code move.
In passing I remove an unneeded call to
update_calculated_fields in the dispatch code,
plus some tests that don't need them.
The only reason to use typeof foo === "undefined" is when foo is a
global identifier that might not have been declared at all, so it
might raise a ReferenceError if evaluated. For a variable declared
with const or let or import, a function argument, or a complex
expression, simply foo === undefined is equivalent.
Some of these conditions have become impossible and can be removed
entirely, and some can be replaced more idiomatically with default
parameters (note that JavaScript does not share the Python misfeature
of evaluating the default parameter at function declaration time).
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This prevents a bug where we interpret "2something"
as a modern slug instead of a legacy stream name.
The bug was probably somewhat unlikely to happen in
practice, since it only manifests if 2 is an actual
stream_id.
The maybe_clear_subscribers() function was an artifact of
when we used to attach subscribers to the "sub" records in
stream_data.js. I think it was basically a refactoring
shim, and due to some other recent cleanup, it was only
used in test code.
We also change how we validate stream ids.
Going forward, peer_data just looks up stream_ids with the
normal stream_data API when it's trying to warn about
rogue stream_ids coming in. As I alluded to in an earlier
commit, some of the warning code here might be overly
defensive, but at least it's pretty self-contained.
We also streamline some of the error handling code
by doing everything up front. This will prevent
scenarios where a single bad stream_id/user_id causes a
bunch of the same warnings in an inner loop.
This removes a bit of complexity. If a piece of
settings code needs to render a stream with
subscribers, it just asks for it.
We no longer have the brittle, action-at-a-distance
mechanism of mutating the subscriber count on to
the stream_data version of a sub.
Stream subs are pretty small, so making copies of
them is cheap, and the blueslip timings from the
previous commit can help confirm that.
There is some discussion of putting `subscriber_count`
on the Stream model, which may eventually get us
away from tracking it in `peer_data.js`, but we will
cross that bridge when we get there. See
https://github.com/zulip/zulip/issues/17101 for
more details.
The goal here is to make all our peer_data functions
basically work in id space. Passing a full `sub`
to these functions is a legacy of when subscriber
info was attached to a full stream "sub" object,
but we don't care about anything sub-related
(color, description, name, etc.) when we are
dealing with subscriptions.
When callers pass in stream_id, you can be more
confident in a quick skim of the code that we're
not mutating anything in the "sub".
This de-clutters stream_data a bit. Since our
peer data is our biggest performance concern,
I want to contain any optimizations to a fairly
well-focused module.
The name `peer_data` is a bit of a compromise,
since we already have `subs.js` and we use
`sub` as a variable name for stream records
throughout our code, but it's consistent with
our event nomenclature (peer/add, peer/remove)
and it's short while still being fairly easy
to find with grep.
This sets us up to use better system-wide data structures
for tracking subscribers.
Basically, instead of storing subscriber data on the
"sub" objects in stream_data.js, we instead have a
parallel data structure called stream_subscribers.
We also have stream_create, stream_edit, and friends
use helper functions rather than accessing
sub.subscribers directly.
We now use add_sub only in tests.
The line to defensively initialize subscribers does
not get copied from add_sub, since we know that
create_sub_from_server_data always initializes
subscribers via set_subscribers.
Instead of prohibiting ‘return undefined’ (#8669), we require that a
function must return an explicit value always or never. This prevents
you from forgetting to return a value in some cases. It will also be
important for TypeScript, which distinguishes between undefined and
void.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
ES and TypeScript modules are strict by default and don’t need this
directive. ESLint will remind us to add it to new CommonJS files and
remove it from ES and TypeScript modules.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
We add a function subscribed_stream_ids which returns an array
of stream ids of all subscribed streams.
This is a prep commit for changing the logic for sorting streams
to store stream ids instead of names.