streams: Refactor multi-option helpers into separate functions.

For internal stream messages, most of the time, we have access to
a Stream object. For the few corner cases where we don't, it is a
much cleaner approach to have a separate function that accepts a
stream name than having one multi-option helper that accepts both
names and objects.

zerver/lib/actions.py

@@ -2325,17 +2325,27 @@ def _internal_prep_message(realm: Realm,
 
 def internal_prep_stream_message(
         realm: Realm, sender: UserProfile,
-        topic: str, content: str,
-        stream_name: Optional[str]=None,
-        stream: Optional[Stream]=None
+        stream: Stream, topic: str, content: str
 ) -> Optional[Dict[str, Any]]:
     """
     See _internal_prep_message for details of how this works.
     """
-    assert stream_name is not None or stream is not None
-    if stream is not None:
     addressee = Addressee.for_stream(stream, topic)
-    else:
+
+    return _internal_prep_message(
+        realm=realm,
+        sender=sender,
+        addressee=addressee,
+        content=content,
+    )
+
+def internal_prep_stream_message_by_name(
+        realm: Realm, sender: UserProfile,
+        stream_name: str, topic: str, content: str
+) -> Optional[Dict[str, Any]]:
+    """
+    See _internal_prep_message for details of how this works.
+    """
     addressee = Addressee.for_stream_name(stream_name, topic)
 
     return _internal_prep_message(
@@ -2402,14 +2412,24 @@ def internal_send_private_message(realm: Realm,
 
 def internal_send_stream_message(
         realm: Realm, sender: UserProfile,
-        topic: str, content: str,
-        stream_name: Optional[str]=None,
-        stream: Optional[Stream]=None
+        stream: Stream, topic: str, content: str
 ) -> None:
     message = internal_prep_stream_message(
-        realm, sender, topic,
-        content, stream_name=stream_name,
-        stream=stream
+        realm, sender, stream,
+        topic, content
+    )
+
+    if message is None:
+        return
+    do_send_messages([message])
+
+def internal_send_stream_message_by_name(
+        realm: Realm, sender: UserProfile,
+        stream_name: str, topic: str, content: str
+) -> None:
+    message = internal_prep_stream_message_by_name(
+        realm, sender, stream_name,
+        topic, content
     )
 
     if message is None:
@@ -3451,11 +3471,11 @@ def do_rename_stream(stream: Stream,
     internal_send_stream_message(
         stream.realm,
         sender,
+        stream,
         "welcome",
         "_@**%s|%d** renamed stream **%s** to **%s**" % (user_profile.full_name,
                                                          user_profile.id,
-                                                         old_name, new_name),
-        stream=stream
+                                                         old_name, new_name)
     )
     # Even though the token doesn't change, the web client needs to update the
     # email forwarding address to display the correctly-escaped new name.

zerver/lib/bot_lib.py

@@ -2,7 +2,7 @@ import json
 import os
 import importlib
 from zerver.lib.actions import internal_send_private_message, \
-    internal_send_stream_message, internal_send_huddle_message
+    internal_send_stream_message_by_name, internal_send_huddle_message
 from zerver.models import UserProfile, get_active_user
 from zerver.lib.bot_storage import get_bot_storage, set_bot_storage, \
     is_key_in_bot_storage, remove_bot_storage
@@ -71,10 +71,9 @@ class EmbeddedBotHandler:
             self._rate_limit.show_error_and_exit()
 
         if message['type'] == 'stream':
-            internal_send_stream_message(
+            internal_send_stream_message_by_name(
                 self.user_profile.realm, self.user_profile,
-                message['topic'], message['content'],
-                stream_name=message['to']
+                message['to'], message['topic'], message['content']
             )
             return
 

zerver/lib/email_mirror.py

@@ -160,9 +160,8 @@ def send_to_missed_message_address(address: str, message: message.Message) -> No
     if recipient.type == Recipient.STREAM:
         stream = get_stream_by_id_in_realm(recipient.type_id, user_profile.realm)
         internal_send_stream_message(
-            user_profile.realm, user_profile,
-            subject_b.decode('utf-8'), body,
-            stream=stream
+            user_profile.realm, user_profile, stream,
+            subject_b.decode('utf-8'), body
         )
     elif recipient.type == Recipient.PERSONAL:
         display_recipient = get_display_recipient(recipient)

zerver/lib/onboarding.py

@@ -2,7 +2,7 @@
 from django.conf import settings
 
 from zerver.lib.actions import set_default_streams, \
-    internal_prep_stream_message, internal_send_private_message, \
+    internal_prep_stream_message_by_name, internal_send_private_message, \
     create_streams_if_needed, do_send_messages, \
     do_add_reaction_legacy, create_users, missing_any_realm_internal_bots
 from zerver.lib.topic import get_turtle_message
@@ -107,10 +107,9 @@ def send_initial_realm_messages(realm: Realm) -> None:
          "in that each conversation should get its own topic. Keep them short, though; one "
          "or two words will do it!"},
     ]  # type: List[Dict[str, str]]
-    messages = [internal_prep_stream_message(
-        realm, welcome_bot,
-        message['topic'], message['content'],
-        stream_name=message['stream']
+    messages = [internal_prep_stream_message_by_name(
+        realm, welcome_bot, message['stream'],
+        message['topic'], message['content']
     ) for message in welcome_messages]
     message_ids = do_send_messages(messages)
 

zerver/tests/test_messages.py

@@ -29,11 +29,12 @@ from zerver.lib.actions import (
     get_last_message_id,
     get_user_info_for_message_updates,
     internal_prep_private_message,
-    internal_prep_stream_message,
+    internal_prep_stream_message_by_name,
     internal_send_huddle_message,
     internal_send_message,
     internal_send_private_message,
     internal_send_stream_message,
+    internal_send_stream_message_by_name,
     send_rate_limited_pm_notification_to_bot_owner,
 )
 
@@ -544,6 +545,18 @@ class InternalPrepTest(ZulipTestCase):
         arg = m.call_args_list[0][0][0]
         self.assertIn('Message must not be empty', arg)
 
+        with mock.patch('logging.exception') as m:
+            internal_send_stream_message_by_name(
+                realm=realm,
+                sender=cordelia,
+                stream_name=stream.name,
+                topic='whatever',
+                content=bad_content
+            )
+
+        arg = m.call_args_list[0][0][0]
+        self.assertIn('Message must not be empty', arg)
+
         with mock.patch('logging.exception') as m:
             internal_send_message(
                 realm=realm,
@@ -598,7 +611,7 @@ class InternalPrepTest(ZulipTestCase):
         topic = 'whatever'
         content = 'hello'
 
-        internal_prep_stream_message(
+        internal_prep_stream_message_by_name(
             realm=realm,
             sender=sender,
             stream_name=stream_name,

zerver/views/streams.py

@@ -398,9 +398,9 @@ def add_subscriptions_backend(
                 internal_prep_stream_message(
                     realm=user_profile.realm,
                     sender=sender,
+                    stream=notifications_stream,
                     topic=topic,
                     content=msg,
-                    stream=notifications_stream
                 )
             )
 

zilencer/management/commands/add_mock_conversation.py

@@ -78,9 +78,8 @@ From image editing program:
         ]  # type: List[Dict[str, Any]]
 
         messages = [internal_prep_stream_message(
-            realm, message['sender'],
-            'message formatting', message['content'],
-            stream=stream
+            realm, message['sender'], stream,
+            'message formatting', message['content']
         ) for message in staged_messages]
 
         message_ids = do_send_messages(messages)