Factor out functions for injecting events into database

I want to add some more flexibility to the tools for injecting events into the
database, and I don't want to clutter up HomeserverTestCase with them, so let's
factor them out to a new file.

synapse/server.pyi

@@ -25,6 +25,7 @@ import synapse.server_notices.server_notices_manager
 import synapse.server_notices.server_notices_sender
 import synapse.state
 import synapse.storage
+from synapse.events.builder import EventBuilderFactory
 
 class HomeServer(object):
     @property
@@ -121,3 +122,7 @@ class HomeServer(object):
         pass
     def get_instance_id(self) -> str:
         pass
+    def get_event_builder_factory(self) -> EventBuilderFactory:
+        pass
+    def get_storage(self) -> synapse.storage.Storage:
+        pass

tests/test_utils/__init__.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2019 New Vector Ltd
+# Copyright 2020 The Matrix.org Foundation C.I.C
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,3 +17,22 @@
 """
 Utilities for running the unit tests
 """
+from typing import Awaitable, TypeVar
+
+TV = TypeVar("TV")
+
+
+def get_awaitable_result(awaitable: Awaitable[TV]) -> TV:
+    """Get the result from an Awaitable which should have completed
+
+    Asserts that the given awaitable has a result ready, and returns its value
+    """
+    i = awaitable.__await__()
+    try:
+        next(i)
+    except StopIteration as e:
+        # awaitable returned a result
+        return e.value
+
+    # if next didn't raise, the awaitable hasn't completed.
+    raise Exception("awaitable has not yet completed")

tests/test_utils/event_injection.py

@@ -0,0 +1,96 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+# Copyright 2020 The Matrix.org Foundation C.I.C
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Optional
+
+import synapse.server
+from synapse.api.constants import EventTypes
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
+from synapse.events import EventBase
+from synapse.types import Collection
+
+from tests.test_utils import get_awaitable_result
+
+
+"""
+Utility functions for poking events into the storage of the server under test.
+"""
+
+
+def inject_member_event(
+    hs: synapse.server.HomeServer,
+    room_id: str,
+    sender: str,
+    membership: str,
+    target: Optional[str] = None,
+    extra_content: Optional[dict] = None,
+    **kwargs
+) -> EventBase:
+    """Inject a membership event into a room."""
+    if target is None:
+        target = sender
+
+    content = {"membership": membership}
+    if extra_content:
+        content.update(extra_content)
+
+    return inject_event(
+        hs,
+        room_id=room_id,
+        type=EventTypes.Member,
+        sender=sender,
+        state_key=target,
+        content=content,
+        **kwargs
+    )
+
+
+def inject_event(
+    hs: synapse.server.HomeServer,
+    room_version: Optional[str] = None,
+    prev_event_ids: Optional[Collection[str]] = None,
+    **kwargs
+) -> EventBase:
+    """Inject a generic event into a room
+
+    Args:
+        hs: the homeserver under test
+        room_version: the version of the room we're inserting into.
+            if not specified, will be looked up
+        prev_event_ids: prev_events for the event. If not specified, will be looked up
+        kwargs: fields for the event to be created
+    """
+    test_reactor = hs.get_reactor()
+
+    if room_version is None:
+        d = hs.get_datastore().get_room_version_id(kwargs["room_id"])
+        test_reactor.advance(0)
+        room_version = get_awaitable_result(d)
+
+    builder = hs.get_event_builder_factory().for_room_version(
+        KNOWN_ROOM_VERSIONS[room_version], kwargs
+    )
+    d = hs.get_event_creation_handler().create_new_client_event(
+        builder, prev_event_ids=prev_event_ids
+    )
+    test_reactor.advance(0)
+    event, context = get_awaitable_result(d)
+
+    d = hs.get_storage().persistence.persist_event(event, context)
+    test_reactor.advance(0)
+    get_awaitable_result(d)
+
+    return event

tests/unittest.py

@@ -32,7 +32,6 @@ from twisted.python.threadpool import ThreadPool
 from twisted.trial import unittest
 
 from synapse.api.constants import EventTypes, Membership
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.ratelimiting import FederationRateLimitConfig
 from synapse.federation.transport import server as federation_server
@@ -55,6 +54,7 @@ from tests.server import (
     render,
     setup_test_homeserver,
 )
+from tests.test_utils import event_injection
 from tests.test_utils.logging_setup import setup_logging
 from tests.utils import default_config, setupdb
 
@@ -596,36 +596,14 @@ class HomeserverTestCase(TestCase):
         """
         Inject a membership event into a room.
 
+        Deprecated: use event_injection.inject_room_member directly
+
         Args:
             room: Room ID to inject the event into.
             user: MXID of the user to inject the membership for.
             membership: The membership type.
         """
-        event_builder_factory = self.hs.get_event_builder_factory()
-        event_creation_handler = self.hs.get_event_creation_handler()
-
-        room_version = self.get_success(
-            self.hs.get_datastore().get_room_version_id(room)
-        )
-
-        builder = event_builder_factory.for_room_version(
-            KNOWN_ROOM_VERSIONS[room_version],
-            {
-                "type": EventTypes.Member,
-                "sender": user,
-                "state_key": user,
-                "room_id": room,
-                "content": {"membership": membership},
-            },
-        )
-
-        event, context = self.get_success(
-            event_creation_handler.create_new_client_event(builder)
-        )
-
-        self.get_success(
-            self.hs.get_storage().persistence.persist_event(event, context)
-        )
+        event_injection.inject_member_event(self.hs, room, user, membership)
 
 
 class FederatingHomeserverTestCase(HomeserverTestCase):

tox.ini

@@ -204,6 +204,7 @@ commands = mypy \
             synapse/storage/database.py \
             synapse/streams \
             synapse/util/caches/stream_change_cache.py \
+            tests/test_utils \
             tests/util/test_stream_change_cache.py
 
 # To find all folders that pass mypy you run: