test_events: Extract BaseAction.

docs/subsystems/events-system.md

@@ -219,7 +219,7 @@ The design above achieves everything we desire, at the cost that we
 need to write a correct `apply_events` function.  This is a difficult
 function to implement correctly, because the situations that it tests
 for almost never happen (being race conditions).  So we have a special
-test class, `EventsRegisterTest`, that is specifically designed to
+helper test class, `BaseAction`, that is specifically designed to
 test this function by ensuring the possible race condition always
 happens.  In particular, it does the following:
 
@@ -231,7 +231,7 @@ e.g. `do_change_full_name`, and capture any events that are generated.
   `fetch_initial_state_data` again now.
 
 The `apply_events` code is correct if those two results are identical.
-The `EventsRegisterTest` tests in `test_events` will print a diff
+The `BaseAction` tests in `test_events` will print a diff
 between the "hybrid state" and the "normal state" obtained from
 calling `fetch_initial_state_data` after the changes.  Those tests
 also inspect the events generated to ensure they have the expected
@@ -242,9 +242,9 @@ to differ what what it was before (which help catch common classes of
 bugs).
 
 The final detail we need to ensure that `apply_events` always works
-correctly is to make sure that we have `EventsRegisterTest` tests for
+correctly is to make sure that we have relevant tests for
 every event type that can be generated by Zulip.  This can be tested
-manually using `test-backend --coverage EventsRegisterTest` and then
+manually using `test-backend --coverage BaseAction` and then
 checking that all the calls to `send_event` are covered.  Someday
 we'll add automation that verifies this directly by inspecting the
 coverage data.

docs/testing/testing-with-django.md

@@ -398,7 +398,7 @@ below some threshold.
 The Zulip back end has a mechanism where it will fetch initial data
 for a client from the database, and then it will subsequently apply
 some queued up events to that data to the data structure before notifying
-the client.  The `EventsRegisterTest.do_test()` helper helps tests
+the client.  The `BaseAction.do_test()` helper helps tests
 verify that the application of those events via apply_events() produces
 the same data structure as performing an action that generates said event.
 

zerver/lib/events.py

@@ -84,7 +84,7 @@ def always_want(msg_type: str) -> bool:
 # Fetch initial data.  When event_types is not specified, clients want
 # all event types.  Whenever you add new code to this function, you
 # should also add corresponding events for changes in the data
-# structures and new code to apply_events (and add a test in EventsRegisterTest).
+# structures and new code to apply_events (and add a test in test_events.py).
 def fetch_initial_state_data(user_profile: UserProfile,
                              event_types: Optional[Iterable[str]],
                              queue_id: str, client_gravatar: bool,

zerver/tests/test_events.py

@@ -164,24 +164,11 @@ basic_stream_fields = [
     ('stream_post_policy', check_int),
 ]
 
-class EventsRegisterTest(ZulipTestCase):
+class BaseAction(ZulipTestCase):
     def setUp(self) -> None:
         super().setUp()
         self.user_profile = self.example_user('hamlet')
 
-    def create_bot(self, email: str, **extras: Any) -> Optional[UserProfile]:
-        return self.create_test_bot(email, self.user_profile, **extras)
-
-    def realm_bot_schema(self, field_name: str, check: Validator[object]) -> Validator[Dict[str, object]]:
-        return check_events_dict([
-            ('type', equals('realm_bot')),
-            ('op', equals('update')),
-            ('bot', check_dict_only([
-                ('user_id', check_int),
-                (field_name, check),
-            ])),
-        ])
-
     def do_test(self, action: Callable[[], object], event_types: Optional[List[str]]=None,
                 include_subscribers: bool=True, state_change_expected: bool=True,
                 notification_settings_null: bool=False, client_gravatar: bool=True,
@@ -310,6 +297,20 @@ class EventsRegisterTest(ZulipTestCase):
             sys.stdout.flush()
             raise AssertionError('Mismatching states')
 
+class NormalActionsTest(BaseAction):
+    def create_bot(self, email: str, **extras: Any) -> Optional[UserProfile]:
+        return self.create_test_bot(email, self.user_profile, **extras)
+
+    def realm_bot_schema(self, field_name: str, check: Validator[object]) -> Validator[Dict[str, object]]:
+        return check_events_dict([
+            ('type', equals('realm_bot')),
+            ('op', equals('update')),
+            ('bot', check_dict_only([
+                ('user_id', check_int),
+                (field_name, check),
+            ])),
+        ])
+
     def test_mentioned_send_message_events(self) -> None:
         user = self.example_user('hamlet')