recent_view_ui: Fix dm rows not updated for deleted messages.

Tested by deleting a DM and navigating to recent view. No error
is thrown and dm row is correctly placed.

Co-authored-by: Tim Abbott <tabbott@zulip.com>

web/src/message_util.ts

@@ -94,6 +94,12 @@ export function get_messages_in_topic(stream_id: number, topic: string): Message
         );
 }
 
+export function get_messages_in_dm_conversations(user_ids_strings: Set<string>): Message[] {
+    return all_messages_data
+        .all_messages()
+        .filter((x) => x.type === "private" && user_ids_strings.has(x.to_user_ids));
+}
+
 export function get_max_message_id_in_stream(stream_id: number): number {
     let max_message_id = 0;
     for (const msg of all_messages_data.all_messages()) {

web/src/recent_view_ui.ts

@@ -794,6 +794,31 @@ export function update_topics_of_deleted_message_ids(message_ids: number[]): voi
         msgs_to_process.push(...msgs);
     }
 
+    const dm_conversations_to_rerender = new Set<string>();
+    for (const msg_id of message_ids) {
+        const msg = message_store.get(msg_id);
+        if (msg === undefined) {
+            continue;
+        }
+
+        if (msg.type === "private") {
+            const key = recent_view_util.get_key_from_message(msg);
+            // Important to assert since we use the key in get_messages_in_dm_conversation.
+            assert(key === msg.to_user_ids);
+            dm_conversations_to_rerender.add(key);
+        }
+    }
+
+    for (const key of dm_conversations_to_rerender) {
+        recent_view_data.conversations.delete(key);
+    }
+    if (dm_conversations_to_rerender.size > 0) {
+        const dm_messages_to_process = message_util.get_messages_in_dm_conversations(
+            dm_conversations_to_rerender,
+        );
+        msgs_to_process.push(...dm_messages_to_process);
+    }
+
     if (msgs_to_process.length > 0) {
         process_messages(msgs_to_process);
     } else {