We're migrating to using the cleaner zulip.com domain, which involves
changing all of our links from ReadTheDocs and other places to point
to the cleaner URL.
Generated by pyupgrade --py36-plus --keep-percent-format, but with the
NamedTuple changes reverted (see commit
ba7906a3c6, #15132).
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This adds 'target_users' parameter to 'attempt_unsubscribe_of_principal`
function in test_subs.py, which accepts list of UserProfile objects to be
unsubscribed, instead of defining users in the function itself.
This change makes the code cleaner and more readable.
Also, 'other_user_subbed' parameter is changed to 'target_users_subbed'
to clearly depict the use of this parameter.
We pipe realm_id through functions where it is available,
this helps us avoid doing query for realm_id in loop when
multiple messages are being processed.
This commit modifies the backend to accept user ids when subscribing
users to streams.
It also migrates all existing tests to use this API, aside from a
small set of tests for the legacy API.
mock is just a backport of the standard library’s unittest.mock now.
The SAMLAuthBackendTest change is needed because
MagicMock.call_args.args wasn’t introduced until Python
3.8 (https://bugs.python.org/issue21269).
The PROVISION_VERSION bump is skipped because mock is still an
indirect dev requirement via moto.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This commit merges do_change_is_admin and do_change_is_guest to a
single function do_change_user_role which will be used for changing
role of users.
do_change_is_api_super_user is added as a separate function for
changing is_api_super_user field of UserProfile.
This commit allows non admins to set stream post policy while creating
streams.
Restriction was there to prevent user from creating a stream in which
the user cannot post himself but this will be taken care of with
stream admin feature.
Refactored code in actions.py and streams.py to move stream related
functions into streams.py and remove the dependency on actions.py.
validate_sender_can_write_to_stream function in actions.py was renamed
to access_stream_for_send_message in streams.py.
This refactors add_default_stream in zerver/views/streams.py to
take in stream_id as parameter instead of stream_name.
Minor changes have been made to test_subs.py and settings_streams.js
accordingly.
Generated by `pyupgrade --py3-plus --keep-percent-format` on all our
Python code except `zthumbor` and `zulip-ec2-configure-interfaces`,
followed by manual indentation fixes.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This commit corrects the test_change_stream_policy_requires_realm_admin
by setting the date_joined of user in the tests itself.
test_non_admin is added to avoid duplication of code.
Code is added for checking success on changing stream_post_policy
by admins.
This is a prep commit for making use of same choices for
create_stream_policy and invite_to_stream_policy as both fields
have same set of choices.
This will be useful as we add other fields using these same types.
This commit replaces the WAITING _PERIOD with FULL_MEMBERS from
create_stream_policy and invite_to_stream_policy choices to
achieve consistency and making the variables more descriptive.
This setting is being overridden by the frontend since the last
commit, and the security model is clearer and more robust if we don't
make it appear as though the markdown processor is handling this
issue.
Co-authored-by: Tim Abbott <tabbott@zulipchat.com>
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This is a full-stack change:
- server
- JS code
- templates
It's all pretty simple--just use stream_id instead
of stream_name.
I am 99% sure we don't document this API nor use it
in mobile, so it should be a safe change.
We try to use the correct variation of `email`
or `delivery_email`, even though in some
databases they are the same.
(To find the differences, I temporarily hacked
populate_db to use different values for email
and delivery_email, and reduced email visibility
in the zulip realm to admins only.)
In places where we want the "normal" realm
behavior of showing emails (and having `email`
be the same as `delivery_email`), we use
the new `reset_emails_in_zulip_realm` helper.
A couple random things:
- I fixed any error messages that were leaking
the wrong email
- a test that claimed to rely on the order
of emails no longer does (we sort user_ids
instead)
- we now use user_ids in some place where we used
to use emails
- for IRC mirrors I just punted and used
`reset_emails_in_zulip_realm` in most places
- for MIT-related tests, I didn't fix email
vs. delivery_email unless it was obvious
I also explicitly reset the realm to a "normal"
realm for a couple tests that I frankly just didn't
have the energy to debug. (Also, we do want some
coverage on the normal case, even though it is
"easier" for tests to pass if you mix up `email`
and `delivery_email`.)
In particular, I just reset data for the analytics
and corporate tests.
We now have this API...
If you really just need to log in
and not do anything with the actual
user:
self.login('hamlet')
If you're gonna use the user in the
rest of the test:
hamlet = self.example_user('hamlet')
self.login_user(hamlet)
If you are specifically testing
email/password logins (used only in 4 places):
self.login_by_email(email, password)
And for failures uses this (used twice):
self.assert_login_failure(email)
This reduces query counts in some cases, since
we no longer need to look up the user again. In
particular, it reduces some noise when we
count queries for O(N)-related tests.
The query count is usually reduced by 2 per
API call. We no longer need to look up Realm
and UserProfile. In most cases we are saving
these lookups for the whole tests, since we
usually already have the `user` objects for
other reasons. In a few places we are simply
moving where that query happens within the
test.
In some places I shorten names like `test_user`
or `user_profile` to just be `user`.
This commit mostly makes our tests less
noisy, since emails are no longer an important
detail of sending messages (they're not even
really used in the API).
It also sets us up to have more scrutiny
on delivery_email/email in the future
for things that actually matter. (This is
a prep commit for something along those
lines, kind of hard to explain the full
plan.)
We were only checking error handling before, not
the happy path. The structure of the code
made it so that we effectively tested most of the
logic for this use case (since all the other flags
are sort of just filters on top of this), but
obviously we want explicit coverage here. Also,
we weren't testing the is-admin-but-not-api-super-user
error checking until this commit.
This fixes a confusing aspect of how our automated tests worked
previously, where we'd almost all HTTP requests in the unlikely
configuration with no User-Agent string specified.
We need to adjust query counts in a few tests that now are a bit
cheaper because they now can take advantage of a Client object created
in server_initialization.py in `process_client`.
This commit includes a new `stream_post_policy` setting,
by replacing the `is_announcement_only` field from the Stream model,
which is done by mirroring the structure of the existing
`create_stream_policy`.
It includes the necessary schema and database migrations to migrate
the is_announcement_only boolean field to stream_post_policy,
a smallPositiveInteger field similar to many other settings.
This change is done to allow organization administrators to restrict
new members from creating and posting to a stream. However, this does
not affect admins who are new members.
With many tweaks by tabbott to documentation under /help, etc.
Fixes#13616.
We should take adventage of the recipient field being denormalized into
the Stream model. We don't need to make queries to figure out a stream's
recipient id, so we take advantage of that to eliminate some of
those redundant queries and simplify StreamRecipientMap.
With the recipient field being denormalized into the UserProfile and
Streams models, all current uses of get_stream_recipients can be done
more efficiently, by simply checking the .recipient_id attribute on the
appropriate objects.
With the recipient field being denormalized into the UserProfile and
Streams models, all current uses of bulk_get_recipients can be done more
efficient, by simply checking the .recipient_id attribute on the
appropriate objects.
Adds required API and front-end changes to modify and read the
wildcard_mentions_notify field in the Subscription model.
It includes front-end code to add the setting to the user's "manage
streams" page. This setting will be greyed out when a stream is muted.
The PR also includes back-end code to add the setting the initial state of
a subscription.
New automated tests were added for the API, events system and front-end.
In manual testing, we checked that modifying the setting in the front end
persisted the change in the Subscription model. We noticed the notifications
were not behaving exactly as expected in manual testing; see
https://github.com/zulip/zulip/issues/13073#issuecomment-560263081 .
Tweaked by tabbott to fix real-time synchronization issues.
Fixes: #13429.
MigrationsTestCase is intentionally omitted from this, since migrations
tests are different in their nature and so whatever setUp()
ZulipTestCase may do in the future, MigrationsTestCase may not
necessarily want to replicate.
Priviously, we rendered the topic links using the msg.sender.realm.
This resulted in issues with Zulip's internal bots not having access
to the realm_filters of the destination stream's realm. For example,
sending a message via the email gateway or notification would not
linkify any realm filters that a user would expect them to.
This was used as a helper to construct the final display_recipient when
fetching messages. With the new mechanism of constructing
display_recipient by fetching appropriate users/streams from the
database and cache, this shouldn't be needed anymore.
The user information in display_recipient in cached message_dicts
becomes outdated if the information is changed in any way.
In particular, since we don't have a way to find all the message
objects that might contain PMs after an organization toggles the
setting to hide user email addresses from other users, we had a
situation where client might see inaccurate cached data from before
the transition for a period of up to hours.
We address this by using our generic_bulk_cached_fetch toolchain to
ensure we always are fetching display_recipient data from the database
(and/or a special recipient_id -> display_recipient cache, which we
can flush easily).
Fixes#12818.
The `users/me/subscriptions` endpoint accidentally started returning
subscriber information for each stream. This is convenient, but
unnecessarily costly for those clients which either don't need it
(most API apps) or already acquire this information via /register
(including Zulip's apps).
This change removes that data set from the default response. Clients
which had come to rely on it, or would like to rely on it in future,
may still access it via an additional documented API parameter.
Fixes#12917.
When a person creates a new realm, they'll likely want to create a
bunch of initial streams at once. When doing so, it could be annoying
to have to mark all of the new stream notification messages as read.
Thus to make this process smoother, we should automatically mark
the messages generated by the Notification Bot in the notifications
(announcements) stream, as well as in the newly created stream itself
as read by the stream creator.
Fixes#12765.
Rename notification property `enable_stream_sounds` to
`enable_stream_audible_notifications` to match with other
notification property patterns.
Fixes part of #12304
This renames Subscription.in_home_view field to is_muted, for greater
clarity as to what it does just from seeing the setting name, without
having to look it up.
Also disabled an obsolete test_migrations test.
Fixes#10042.
This commit migrates the Subscription's notification fields from a
BooleanField to a NullBooleanField where a value of None means to
inherit the value from user's profile.
Also includes a migrations to set the corresponding settings to None
if they match the user profile's values. This migration helps us in
getting rid of the weird "Apply to all" widget that we offered on
subscription settings page.
The mobile apps can't handle None appearing as the stream-level
notification settings, so for backwards-compatibility we arrange to
only send True/False to the mobile apps by applying those defaults
server-side. We introduce a notification_settings_null value within a
client_capabilities structure that newer versions of the mobile apps
can use to request the new model.
This mobile compatibility code is pretty effectively tested by the
existing test_events tests for the subscriptions subsystem.
This makes the implementation of `get_realm` consistent with its
declared return type of `Realm` rather than `Optional[Realm]`.
Fixes#12263.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This commit replaces the `create_stream_by_admins_only` setting with a
new `create_stream_policy` setting, which mirroring the structure of
the existing `invite_to_stream_policy`.
This is important preparation for migrating the waiting period feature
to be its own independent setting.
Fixes#12236.
This commit creates a new organization setting that determines whether
a user can invite other users to streams. Previously this was linked
to the waiting period threshold, but this was both not documented and
overly limiting.
With significant tweaks by tabbott to change the database model to not
involve two threshhold fields, edit the tests, etc.
This requires follow-up work to make the create stream policy setting
work how this code implies it should.
Fixes#12042.
This field is primarily intended to support avoiding displaying the
"more topics" feature in new organizations and streams, where we might
know that all messages in the stream are already available in the
browser.
Based on original work by Roman Godov, and significantly modified by
tabbott.
The second migration involved here could be expensive on Zulip Cloud,
but is unlikely to be an issue on other servers.
This is important for situations such as with our Zapier app,
where the requesting user may be a bot that would like to access
its owner's subscriptions.
Tweaked by tabbott to eliminate the 2^N growth of cases in
do_get_streams.
We want to use the baseline features of bugdown, but not fancy things
like inline URL previews, since the whole structure of stream
descriptions is to have a single-line thing supporting some
formatting.
The migration part of this change fixes a bug encountered by some
organizations upgrading from older versions of Zulip.
We do not anticipate our UI for showing stream descriptions looking
reasonable for multi-line descriptions, so we should just ban creating
them.
Given the frontend changes, multi-line descriptions are only likely to
show up from importing content from other tools, in which case
replacing newlines with spaces is cleaner than the alternative.
This change should help people discover to distinguish
silent mentions in text as a part of Zulip syntax while
differentiating them from regular mentions.
If the caller has access to a Stream object, it is wasteful to
query a database for a stream by ID or name. In addition, not
having to go through stream names eliminates various classes of
possible bugs involved with getting a Stream object back.
This commit does the following three things:
1. Update stream model to accomodate rendered description.
2. Render and save the stream rendered description on update.
3. Render and save stream descriptions on creation.
Further, the stream's rendered description is also sent whenever the
stream's description is being sent.
This is preparatory work for eliminating the use of the
non-authoritative marked.js markdown parser for stream descriptions.
This fixes an annoying bug where clicking to subscribe to a stream
would change the color shown in the "manage streams" UI immediately
after you click.
Fixes#11072.
This a check on server side to verify whether the user sending request
to create stream where only admins can post is an admin or not; Raises
a JsonableError when the user is not the realm admin.
Previously, the subscription color attribute had a validator of
check_string, but this is insufficient. Hence this commit update the
validator used to check_color. Fixes#11268.
Feature of sending notification to the stream using notification bot
is added. user_profile is also passed to do_rename_stream for using
the name of user who renamed the stream in notification.
Notification is sent to the stream using
internal_send_stream_message in do_rename_stream.
Fixes#11034.
A key part of this is the new helper, get_user_by_delivery_email. Its
verbose name is important for clarity; it should help avoid blind
copy-pasting of get_user (which we'll also want to rename).
Unfortunately, it requires detailed understanding of the context to
figure out which one to use; each is used in about half of call sites.
Another important note is that this PR doesn't migrate get_user calls
in the tests except where not doing so would cause the tests to fail.
This probably deserves a follow-up refactor to avoid bugs here.
This prevents leaking some variables into an already
cluttered function.
We also add test coverage for what's now an
early-exit condition in the new function--we exempt
public MIT streams from these events.
These test cases are used to test the cost of stream creation.
Three scenarios of stream creation are covered:
1) create a public stream;
2) create a private stream;
3) create a public stream with announce=true when there is a notification stream.
Fix: #4804.
This fixes a bug where administrators couldn't remove private
unsubscribed streams from the "default streams" list, because
access_stream_by_name didn't give them access to the stream object.
This is a preparatory refactor for adding
UserProfile.can_subscribe_other_users.
Although there existed a test for limiting users from creating
streams at `test_subs.test_user_settings_for_adding_streams`,
it did not test the logic inside can_add_streams, tests have
been added to solve that issue.
This is all the plumbing that makes it possible to enable the
stream_email_notifications setting via the Zulip API. The flag still
doesn't do anything yet, but this is a nice checkpoint along the way
to implementing this feature.
We're adding more stream types, e.g. splitting private streams into
with/without shared history, adding publicly-archived streams, adding
announce-only streams, etc. So maintaining this text is going to get more
complicated over time.
Also, the right place to explain this stuff is in the stream header, or near
the z-in-a-circle.
This commit also adds translation tags to the messages.
We essentially stop running create_realm_internal_bots during
every provisioing and move its operations to run from populate db.
In fact to speed things up a bit we actually make populate db call the
funcs which create_realm_internal_bots calls behind the scenes.
Fixes: #9467.
This query was incorreclty not checking whether a user was deactivated
before managing their subscriptions.
This isn't an important bug, but should prevent some weird corner
cases (like trying to send a notification PM to a deactivated user,
which fails).
Most of this is just asserting that the sub_dict return value from
access_stream_by_id is not None in the cases where it shouldn't be,
but additionally, we also need to pass a function into
validate_user_access_to_subscribers_helper (in this case, just `lambda:
True` works fine)
These decorators will be part of the process for disabling access to
various features for guest users.
Adding this decorator to the subscribe endpoint breaks the guest users
test we'd just added for the subscribe code path; we address this by
adding a more base-level test on filter_stream_authorization.
We were rejecting strings of length equal to the max.
While we're at it, fix the unnecessary period in the error message,
which doesn't align with similar validators.
This commit adds a new field history_public_to_subscribers to the
Stream model, which serves a similar function to the old
settings.PRIVATE_STREAM_HISTORY_FOR_SUBSCRIBERS; we still use that
setting as the default value for new streams to avoid breaking
backwards-compatibility for those users before we are ready with an
actual UI for users to choose directly.
This also comes with a migration to set the value of the new field for
existing streams with an algorithm matching that used at runtime.
With significant changes by Tim Abbott.
This is an initial part of our efforts on #9232.
This commit sends the event for renaming of a private stream to
organization admins of the realm, in addition to the obvious list of
subscribers of the private stream.
Normally, admins can manage a private stream (e.g. unsubscribing a
user). But when the admin tried to unsubscribes a user from a
previously renamed stream, we previously were throwing a JS error, as
the webapp hadn't been notified about the new stream name.
Fixes#9034.
There were two instances of `ensure_stream` being called and assigned to
a variable with the variable not being used elsewhere. pyflakes picked
up on this (where it didn't in the previous version likely due to tuple
unpacking), so the the variable assignment has been replaced with a call
to `ensure_stream`.
Issue #2088 asked for a wrapper to be created for
`create_stream_if_needed` (called `ensure_stream`) for the 25 times that
`create_stream_if_needed` is called and ignores whether the stream was
created. This commit replaces relevant occurences of
`create_stream_if_needed` with `ensure_stream`, including imports.
The changes weren't significant enough to add any tests or do any
additional manual testing.
The refactoring intended to make the API easier to use in most cases.
The majority of uses of `create_stream_if_needed` ignored the second
parameter.
Fixes: #2088.
Currently, when other private stream subscriber add realm admin to
stream, new copy private stream is created in realm admin's streams.
Which resulted in error, cause there are two similar stream element
in stream settings.
If new subscriber is added to private stream, we first send them
stream `create` event, cause private stream are not visible until
user don't get subscribed at least once. But realm admins can now
always access private stream, so when realm admin is subscribed to
stream, realm admin get stream `create` event even if stream already
exist in on realm admin client side.
Fix this by extracting realm admins from stream `create` event on
`add` subscription operation and sending private stream `create`
event to all realm admins on stream creation operation.
Fixes#8695
This will allow realm admins to remove others from private stream to
which the realm administrator is not subscribed; this is important for
managing those streams, because previously nobody could remove users
from private streams that didn't have any realm administrators
subscribed.
This will allow realm admins to access subscribers of unsubscribed
private stream. This is a preparatory commit for letting realm admins
remove those users.
This will allow realm admins to update the names and descriptions of
private streams even if they are not subscribed, which fixes the buggy
behavior that previously nobody could(!).
If new private stream is created by realm admin without realm admin
subscribed to it, then it doesn't automatically add created stream to
realm admin's stream list. We have to reload the browser to get newly
created stream in stream list. Cause private stream creation event is
only sent to the subscribed users to private stream, so even if realm
admin is acting user, they don't get creation event.
We should send private stream creation event to realm admin users along
with subscribed user to stream, as realm admins can access unsubscribed
private streams.
Tweaked by tabbott to fix various typos and clean up the code.
This commit prefixes stream names in urls with stream ids,
so that the urls don't break when we rename streams.
strean name: foo bar.com%
before: #narrow/stream/foo.20bar.2Ecom.25
after: #narrow/stream/20-foo-bar.2Ecom.25
For new realms, everything is simple under the new scheme, since
we just parse out the stream id every time to figure out where
to narrow.
For old realms, any old URLs will still work under the new scheme,
assuming the stream hasn't been renamed (and of course old urls
wouldn't have survived stream renaming in the first place). The one
exception is the hopefully rare case of a stream name starting with
something like "99-" and colliding with another stream whose id is 99.
The way that we enocde the stream name portion of the URL is kind
of unimportant now, since we really only look at the stream id, but
we still want a safe encoding of the name that is mostly human
readable, so we now convert spaces to dashes in the stream name. Also,
we try to ensure more code on both sides (frontend and backend) calls
common functions to do the encoding.
Fixes#4713
Because we use access_stream_by_id here, and that checks for an active
subscription to interact with a private stream, this didn't work.
The correct fix to add an option to active_stream_by_id to accept an
argument indicating whether we need an active subscription; for this
use case, we definitely do not.
This fixes a bug where, when a user is unsubscribed from a stream,
they might have unread messages on that stream leak. While it might
seem to be a minor problem, it can cause significant problems for
computing the `unread_msgs` data structures, since it means we need to
add an extra filter for whether the user is still subscribed, either
in the backend or in the UI.
Fixes#7095.
We don't have our linter checking test files due to ultra-long strings
that are often present in test output that we verify. But it's worth
at least cleaning out all the ultra-long def lines.
We extract get_bulk_stream_subscriber_info() from this
function to remove some of the complexity. Also, in that
new function we avoid a hop to the database by querying
on stream ids instead of recipient ids. The query that
gets changed here does require a join to the recipient
table (to get the stream id), so it's a little bit of a
tradeoff.
The first method we extract to this library is
get_active_subscriptions_for_stream_id().
We also move num_subscribers_for_stream_id() to here, which
is slightly annoying (having the method on Stream was nice)
but avoids some circular dependency issues.
In do_send_messages, we only produce one dictionary for
the event queues, instead of different flavors for text
vs. html. This prevents two unnecessary queries to the
database.
It also means we only put one dictionary on the "message"
event queue instead of two, albeit a wider one that has
some values that won't be sent to the actual clients.
This wider dictionary from MessageDict.wide_dict is also
used for the `feedback_messages` queue and service bot
queues. Since the extra fields are possibly useful down
the road, and they'll just be ignored for now, we don't
bother to remove them. Also, those queue processors won't
have access to `content_type`, which they shouldn't need.
Fixes#6947
Add this field to the Stream model will prevent us from having
to look at realm data for several types of stream operations, which
can be prone to either doing extra database lookups or making
our cached data bloated.
Going forward, we'll set stream.is_zephyr to True whenever the
realm's string id is "zephyr".
This removes sender names from the message cache, since
they aren't guaranteed to be valid, and they're inexpensive
to add.
This commit will make the message cache entries smaller
by removing sender___full_name and sender__short_name
fields.
Then we add in the sender fields to the message payloads
by doing a query against the unique sender ids of the
messages we are processing.
This change leads to 2 extra database hops for most of
our message-related codepaths. The reason there are 2 hops
instead of 1 is that we basically re-calculate way too
much data to get a no-markdown dictionary.
This commit prepares us to introduce a StreamLite class. For
these tests, we don't care about the actual contents of the
Stream, just the right stream is there.
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
We don't need full Realm objects to find DefaultStream
objects for a realm. So now a few functions related to
adding/removing default streams use realm_id for lookups.
Similarly, we don't need a full Stream object to find
out if a stream exists in DefaultStream, so we do id
lookups there as well.
This sets us up to use thinner objects in callers.
We now have a dedicated cache for active_user_ids() that only
stores a list of user_ids.
Before this commit, active_user_ids() used a cache of UserProfile
dictionaries, so it incurred unnecessary deserialization costs for
all the user fields that it sliced away in a list comprehension.
Because the cache is skinnier here, we also need to invalidate it
less frequently. Basically, all we care about is new users, realm
deactivations, and user deactivations.
It's hard to measure how much this will improve performance, because
the speedup for any operation here is pretty minor, but we use this
function a lot, so hopefully it will make the overall system more
healthy.
This is mostly a preparatory commit for an upcoming optimization
related to stream data, but it probably does save us an
occasional DB hop to the realm table.
This class encapsulates the mapping of stream ids to
recipient ids, and it is optimized for bulk use and
repeated use (i.e. it remembers values it already fetched).
This particular commit barely improves the performance
of gather_subscriptions_helper, but it sets us up for
further optimizations.
Long term, we may try to denormalize stream_id on to the
Subscriber table or otherwise modify the database so we
don't have to jump through hoops to do this kind of mapping.
This commit will help enable those changes, because we
isolate the mapping to this one new class.
Usually a small minority of users are eligible to receive missed
message emails or mobile notifications.
We now filter users first before hitting UserPresence to find idle
users. We also simply check for the existence of recent activity
rather than borrowing the more complicated data structures that we
use for the buddy list.
Admins need to know about private streams to delete them, even
if they are not subscribed. We send the minimal info possible
to the client to allow them to have a UI for that.
Unlike creating a stream, there's really no reason one would want to
call the function to create a realm while uncertain whether that realm
already existed.
This route is called only in `js/compose.js`, to handle autosubscribe.
That code doesn't check this "exists" field, because there's no need
-- the same information is already carried in whether the result was
success or failure. So just eliminate it.
This makes the logic here a little simpler. It also eliminates
another usage of the `data` parameter to `json_error`. I have half a
mind to eliminate that parameter, in favor of making `JsonableError`
subclasses whenever there's structured data to include, in particular
to get the benefits of typing. There are a couple of places where
that change isn't locally a clear win, but this is not one of them.
The SubscriptionAPITest class variables `realm` and `test_realm` stores
the same information and are redundant. I have eliminated all occurances
of self.realm and replaced with self.test_realm.
When the last user on a private stream is removed, the stream is no
longer possible to administer, and thus should be marked as
deactivated, so that default streams entries are removed and it no
longer appears in the UI as a non-administerable broken stream.