mypy: Improve type checks for user display recipients.

zerver/lib/display_recipient.py

@@ -34,16 +34,17 @@ def get_display_recipient_cache_key(
 @cache_with_key(get_display_recipient_cache_key, timeout=3600 * 24 * 7)
 def get_display_recipient_remote_cache(
     recipient_id: int, recipient_type: int, recipient_type_id: Optional[int]
-) -> DisplayRecipientT:
+) -> List[UserDisplayRecipient]:
     """
-    returns: an appropriate object describing the recipient.  For a
-    stream this will be the stream name as a string.  For a huddle or
-    personal, it will be an array of dicts about each recipient.
+    This returns an appropriate object describing the recipient of a
+    direct message (whether individual or group).
+
+    It will be an array of dicts for each recipient.
+
+    Do not use this for streams.
     """
-    if recipient_type == Recipient.STREAM:  # nocoverage
-        assert recipient_type_id is not None
-        stream = Stream.objects.values("name").get(id=recipient_type_id)
-        return stream["name"]
+
+    assert recipient_type != Recipient.STREAM
 
     # The main priority for ordering here is being deterministic.
     # Right now, we order by ID, which matches the ordering of user

zerver/lib/email_mirror.py

@@ -460,7 +460,6 @@ def process_missed_message(to: str, message: EmailMessage) -> None:
         internal_send_private_message(user_profile, recipient_user, body)
     elif recipient.type == Recipient.HUDDLE:
         display_recipient = get_display_recipient(recipient)
-        assert not isinstance(display_recipient, str)
         emails = [user_dict["email"] for user_dict in display_recipient]
         recipient_str = ", ".join(emails)
         internal_send_huddle_message(user_profile.realm, user_profile, emails, body)

zerver/lib/email_notifications.py

@@ -269,7 +269,6 @@ def build_message_list(
         elif message.recipient.type == Recipient.HUDDLE:
             grouping = {"huddle": message.recipient_id}
             display_recipient = get_display_recipient(message.recipient)
-            assert not isinstance(display_recipient, str)
             narrow_link = huddle_narrow_url(
                 user=user,
                 display_recipient=display_recipient,
@@ -475,8 +474,6 @@ def do_send_missedmessage_events_reply_in_zulip(
     senders = list({m["message"].sender for m in missed_messages})
     if missed_messages[0]["message"].recipient.type == Recipient.HUDDLE:
         display_recipient = get_display_recipient(missed_messages[0]["message"].recipient)
-        # Make sure that this is a list of strings, not a string.
-        assert not isinstance(display_recipient, str)
         narrow_url = huddle_narrow_url(
             user=user_profile,
             display_recipient=display_recipient,

zerver/lib/message.py

@@ -989,15 +989,12 @@ def render_markdown(
 
 
 def huddle_users(recipient_id: int) -> str:
-    display_recipient: DisplayRecipientT = get_display_recipient_by_id(
+    display_recipient: List[UserDisplayRecipient] = get_display_recipient_by_id(
         recipient_id,
         Recipient.HUDDLE,
         None,
     )
 
-    # str is for streams.
-    assert not isinstance(display_recipient, str)
-
     user_ids: List[int] = [obj["id"] for obj in display_recipient]
     user_ids = sorted(user_ids)
     return ",".join(str(uid) for uid in user_ids)

zerver/models.py

@@ -87,7 +87,6 @@ from zerver.lib.pysa import mark_sanitized
 from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.lib.types import (
     DefaultStreamDict,
-    DisplayRecipientT,
     ExtendedFieldElement,
     ExtendedValidator,
     FieldElement,
@@ -99,6 +98,7 @@ from zerver.lib.types import (
     RealmPlaygroundDict,
     RealmUserValidator,
     UnspecifiedValue,
+    UserDisplayRecipient,
     UserFieldElement,
     Validator,
 )
@@ -191,12 +191,12 @@ def query_for_ids(
 # could be replaced with smarter bulk-fetching logic that deduplicates
 # queries for the same recipient; this is just a convenient way to
 # write that code.
-per_request_display_recipient_cache: Dict[int, DisplayRecipientT] = {}
+per_request_display_recipient_cache: Dict[int, List[UserDisplayRecipient]] = {}
 
 
 def get_display_recipient_by_id(
     recipient_id: int, recipient_type: int, recipient_type_id: Optional[int]
-) -> DisplayRecipientT:
+) -> List[UserDisplayRecipient]:
     """
     returns: an object describing the recipient (using a cache).
     If the type is a stream, the type_id must be an int; a string is returned.
@@ -211,7 +211,7 @@ def get_display_recipient_by_id(
     return per_request_display_recipient_cache[recipient_id]
 
 
-def get_display_recipient(recipient: "Recipient") -> DisplayRecipientT:
+def get_display_recipient(recipient: "Recipient") -> List[UserDisplayRecipient]:
     return get_display_recipient_by_id(
         recipient.id,
         recipient.type,

zerver/tests/test_message_fetch.py

@@ -43,7 +43,7 @@ from zerver.lib.streams import StreamDict, create_streams_if_needed, get_public_
 from zerver.lib.test_classes import ZulipTestCase
 from zerver.lib.test_helpers import HostRequestMock, get_user_messages, queries_captured
 from zerver.lib.topic import MATCH_TOPIC, RESOLVED_TOPIC_PREFIX, TOPIC_NAME
-from zerver.lib.types import DisplayRecipientT
+from zerver.lib.types import UserDisplayRecipient
 from zerver.lib.upload.base import create_attachment
 from zerver.lib.url_encoding import near_message_url
 from zerver.lib.user_topics import set_topic_visibility_policy
@@ -2024,11 +2024,11 @@ class GetOldMessagesTest(ZulipTestCase):
         """
         me = self.example_user("hamlet")
 
-        def dr_emails(dr: DisplayRecipientT) -> str:
+        def dr_emails(dr: List[UserDisplayRecipient]) -> str:
             assert isinstance(dr, list)
             return ",".join(sorted({*(r["email"] for r in dr), me.email}))
 
-        def dr_ids(dr: DisplayRecipientT) -> List[int]:
+        def dr_ids(dr: List[UserDisplayRecipient]) -> List[int]:
             assert isinstance(dr, list)
             return sorted({*(r["id"] for r in dr), self.example_user("hamlet").id})