events: Add RoomMessageEventContentWithoutRelation::add_mentions

crates/ruma-events/CHANGELOG.md

@@ -10,6 +10,7 @@ Improvements:
   `RoomMessageEventContent`:
   - `make_reply_to`
   - `make_reply_to_raw`
+  - `add_mentions`
 
 # 0.27.0
 

crates/ruma-events/src/lib.rs

@@ -272,6 +272,11 @@ impl Mentions {
     pub fn with_room_mention() -> Self {
         Self { room: true, ..Default::default() }
     }
+
+    fn add(&mut self, mentions: Self) {
+        self.user_ids.extend(mentions.user_ids);
+        self.room |= mentions.room;
+    }
 }
 
 // Wrapper around `Box<str>` that cannot be used in a meaningful way outside of

crates/ruma-events/src/room/message.rs

@@ -348,13 +348,7 @@ impl RoomMessageEventContent {
     ///
     /// [mentions]: https://spec.matrix.org/latest/client-server-api/#user-and-room-mentions
     pub fn add_mentions(mut self, mentions: Mentions) -> Self {
-        if let Some(m) = &mut self.mentions {
+        self.mentions.get_or_insert_with(Mentions::new).add(mentions);
-            m.user_ids.extend(mentions.user_ids);
-            m.room |= mentions.room;
-        } else {
-            self.mentions = Some(mentions);
-        }
-
         self
     }
 

crates/ruma-events/src/room/message/without_relation.rs

@@ -213,6 +213,18 @@ impl RoomMessageEventContentWithoutRelation {
         self.make_reply_tweaks(original_event_id, original_thread_id, sender_for_mentions)
     }
 
+    /// Add the given [mentions] to this event.
+    ///
+    /// If no [`Mentions`] was set on this events, this sets it. Otherwise, this updates the current
+    /// mentions by extending the previous `user_ids` with the new ones, and applies a logical OR to
+    /// the values of `room`.
+    ///
+    /// [mentions]: https://spec.matrix.org/latest/client-server-api/#user-and-room-mentions
+    pub fn add_mentions(mut self, mentions: Mentions) -> Self {
+        self.mentions.get_or_insert_with(Mentions::new).add(mentions);
+        self
+    }
+
     fn make_reply_tweaks(
         mut self,
         original_event_id: OwnedEventId,