Channel chat: Add edit message (#9035)

**Summary**:
- Removed reply message from message_menu
- Made render_popover_buttons a bit more reusable
- Fixed issue that you can't close the reply/edit preview when you are
not focusing the message editor
- Notify only the new people that were mentioned inside the edited
message

**Follow up**
- Fix that we update the notification message for the people that we
mentioned already
- Fix that we remove the notification when a message gets deleted.
  - Fix last acknowledge message id is in correct now

**Todo**:
- [x] Add tests
- [x] Change new added bindings to the `Editor::Cancel` event.

Release Notes:

- Added editing of chat messages
([#6707](https://github.com/zed-industries/zed/issues/6707)).

<img width="239" alt="Screenshot 2024-03-09 at 11 55 23"
src="https://github.com/zed-industries/zed/assets/62463826/b0949f0d-0f8b-43e1-ac20-4c6d40ac41e1">
<img width="240" alt="Screenshot 2024-03-13 at 13 34 23"
src="https://github.com/zed-industries/zed/assets/62463826/d0636da2-c5aa-4fed-858e-4bebe5695ba7">

---------

Co-authored-by: Bennet Bo Fenner <53836821+bennetbo@users.noreply.github.com>
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

assets/icons/pencil.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?><!-- Uploaded to: SVG Repo, www.svgrepo.com, Generator: SVG Repo Mixer Tools -->
+<svg width="800px" height="800px" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M18 10L21 7L17 3L14 6M18 10L8 20H4V16L14 6M18 10L14 6" stroke="#000000" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/>
+</svg>

assets/keymaps/default-macos.json

@@ -597,12 +597,6 @@
       "tab": "channel_modal::ToggleMode"
     }
   },
-  {
-    "context": "ChatPanel > MessageEditor",
-    "bindings": {
-      "escape": "chat_panel::CloseReplyPreview"
-    }
-  },
   {
     "context": "Terminal",
     "bindings": {

crates/channel/src/channel_chat.rs

@@ -51,6 +51,7 @@ pub struct ChannelMessage {
     pub nonce: u128,
     pub mentions: Vec<(Range<usize>, UserId)>,
     pub reply_to_message_id: Option<u64>,
+    pub edited_at: Option<OffsetDateTime>,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -83,6 +84,10 @@ pub enum ChannelChatEvent {
         old_range: Range<usize>,
         new_count: usize,
     },
+    UpdateMessage {
+        message_id: ChannelMessageId,
+        message_ix: usize,
+    },
     NewMessage {
         channel_id: ChannelId,
         message_id: u64,
@@ -93,6 +98,7 @@ impl EventEmitter<ChannelChatEvent> for ChannelChat {}
 pub fn init(client: &Arc<Client>) {
     client.add_model_message_handler(ChannelChat::handle_message_sent);
     client.add_model_message_handler(ChannelChat::handle_message_removed);
+    client.add_model_message_handler(ChannelChat::handle_message_updated);
 }
 
 impl ChannelChat {
@@ -189,6 +195,7 @@ impl ChannelChat {
                     mentions: message.mentions.clone(),
                     nonce,
                     reply_to_message_id: message.reply_to_message_id,
+                    edited_at: None,
                 },
                 &(),
             ),
@@ -234,6 +241,35 @@ impl ChannelChat {
         })
     }
 
+    pub fn update_message(
+        &mut self,
+        id: u64,
+        message: MessageParams,
+        cx: &mut ModelContext<Self>,
+    ) -> Result<Task<Result<()>>> {
+        self.message_update(
+            ChannelMessageId::Saved(id),
+            message.text.clone(),
+            message.mentions.clone(),
+            Some(OffsetDateTime::now_utc()),
+            cx,
+        );
+
+        let nonce: u128 = self.rng.gen();
+
+        let request = self.rpc.request(proto::UpdateChannelMessage {
+            channel_id: self.channel_id.0,
+            message_id: id,
+            body: message.text,
+            nonce: Some(nonce.into()),
+            mentions: mentions_to_proto(&message.mentions),
+        });
+        Ok(cx.spawn(move |_, _| async move {
+            request.await?;
+            Ok(())
+        }))
+    }
+
     pub fn load_more_messages(&mut self, cx: &mut ModelContext<Self>) -> Option<Task<Option<()>>> {
         if self.loaded_all_messages {
             return None;
@@ -523,6 +559,32 @@ impl ChannelChat {
         Ok(())
     }
 
+    async fn handle_message_updated(
+        this: Model<Self>,
+        message: TypedEnvelope<proto::ChannelMessageUpdate>,
+        _: Arc<Client>,
+        mut cx: AsyncAppContext,
+    ) -> Result<()> {
+        let user_store = this.update(&mut cx, |this, _| this.user_store.clone())?;
+        let message = message
+            .payload
+            .message
+            .ok_or_else(|| anyhow!("empty message"))?;
+
+        let message = ChannelMessage::from_proto(message, &user_store, &mut cx).await?;
+
+        this.update(&mut cx, |this, cx| {
+            this.message_update(
+                message.id,
+                message.body,
+                message.mentions,
+                message.edited_at,
+                cx,
+            )
+        })?;
+        Ok(())
+    }
+
     fn insert_messages(&mut self, messages: SumTree<ChannelMessage>, cx: &mut ModelContext<Self>) {
         if let Some((first_message, last_message)) = messages.first().zip(messages.last()) {
             let nonces = messages
@@ -599,6 +661,38 @@ impl ChannelChat {
             }
         }
     }
+
+    fn message_update(
+        &mut self,
+        id: ChannelMessageId,
+        body: String,
+        mentions: Vec<(Range<usize>, u64)>,
+        edited_at: Option<OffsetDateTime>,
+        cx: &mut ModelContext<Self>,
+    ) {
+        let mut cursor = self.messages.cursor::<ChannelMessageId>();
+        let mut messages = cursor.slice(&id, Bias::Left, &());
+        let ix = messages.summary().count;
+
+        if let Some(mut message_to_update) = cursor.item().cloned() {
+            message_to_update.body = body;
+            message_to_update.mentions = mentions;
+            message_to_update.edited_at = edited_at;
+            messages.push(message_to_update, &());
+            cursor.next(&());
+        }
+
+        messages.append(cursor.suffix(&()), &());
+        drop(cursor);
+        self.messages = messages;
+
+        cx.emit(ChannelChatEvent::UpdateMessage {
+            message_ix: ix,
+            message_id: id,
+        });
+
+        cx.notify();
+    }
 }
 
 async fn messages_from_proto(
@@ -623,6 +717,15 @@ impl ChannelMessage {
                 user_store.get_user(message.sender_id, cx)
             })?
             .await?;
+
+        let edited_at = message.edited_at.and_then(|t| -> Option<OffsetDateTime> {
+            if let Ok(a) = OffsetDateTime::from_unix_timestamp(t as i64) {
+                return Some(a);
+            }
+
+            None
+        });
+
         Ok(ChannelMessage {
             id: ChannelMessageId::Saved(message.id),
             body: message.body,
@@ -641,6 +744,7 @@ impl ChannelMessage {
                 .ok_or_else(|| anyhow!("nonce is required"))?
                 .into(),
             reply_to_message_id: message.reply_to_message_id,
+            edited_at,
         })
     }
 

crates/channel/src/channel_store_tests.rs

@@ -186,6 +186,7 @@ async fn test_channel_messages(cx: &mut TestAppContext) {
                     mentions: vec![],
                     nonce: Some(1.into()),
                     reply_to_message_id: None,
+                    edited_at: None,
                 },
                 proto::ChannelMessage {
                     id: 11,
@@ -195,6 +196,7 @@ async fn test_channel_messages(cx: &mut TestAppContext) {
                     mentions: vec![],
                     nonce: Some(2.into()),
                     reply_to_message_id: None,
+                    edited_at: None,
                 },
             ],
             done: false,
@@ -243,6 +245,7 @@ async fn test_channel_messages(cx: &mut TestAppContext) {
             mentions: vec![],
             nonce: Some(3.into()),
             reply_to_message_id: None,
+            edited_at: None,
         }),
     });
 
@@ -297,6 +300,7 @@ async fn test_channel_messages(cx: &mut TestAppContext) {
                     nonce: Some(4.into()),
                     mentions: vec![],
                     reply_to_message_id: None,
+                    edited_at: None,
                 },
                 proto::ChannelMessage {
                     id: 9,
@@ -306,6 +310,7 @@ async fn test_channel_messages(cx: &mut TestAppContext) {
                     nonce: Some(5.into()),
                     mentions: vec![],
                     reply_to_message_id: None,
+                    edited_at: None,
                 },
             ],
         },

crates/collab/migrations.sqlite/20221109000000_test_schema.sql

@@ -219,6 +219,7 @@ CREATE TABLE IF NOT EXISTS "channel_messages" (
     "sender_id" INTEGER NOT NULL REFERENCES users (id),
     "body" TEXT NOT NULL,
     "sent_at" TIMESTAMP,
+    "edited_at" TIMESTAMP,
     "nonce" BLOB NOT NULL,
     "reply_to_message_id" INTEGER DEFAULT NULL
 );

crates/collab/migrations/20240221151017_add_edited_at_field_to_channel_message.sql

@@ -0,0 +1 @@
+ALTER TABLE channel_messages ADD edited_at TIMESTAMP DEFAULT NULL;

crates/collab/src/db.rs

@@ -458,6 +458,14 @@ pub struct CreatedChannelMessage {
     pub notifications: NotificationBatch,
 }
 
+pub struct UpdatedChannelMessage {
+    pub message_id: MessageId,
+    pub participant_connection_ids: Vec<ConnectionId>,
+    pub notifications: NotificationBatch,
+    pub reply_to_message_id: Option<MessageId>,
+    pub timestamp: PrimitiveDateTime,
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, FromQueryResult, Serialize, Deserialize)]
 pub struct Invite {
     pub email_address: String,

crates/collab/src/db/queries/messages.rs

@@ -162,6 +162,9 @@ impl Database {
                         lower_half: nonce.1,
                     }),
                     reply_to_message_id: row.reply_to_message_id.map(|id| id.to_proto()),
+                    edited_at: row
+                        .edited_at
+                        .map(|t| t.assume_utc().unix_timestamp() as u64),
                 }
             })
             .collect::<Vec<_>>();
@@ -199,6 +202,31 @@ impl Database {
         Ok(messages)
     }
 
+    fn format_mentions_to_entities(
+        &self,
+        message_id: MessageId,
+        body: &str,
+        mentions: &[proto::ChatMention],
+    ) -> Result<Vec<tables::channel_message_mention::ActiveModel>> {
+        Ok(mentions
+            .iter()
+            .filter_map(|mention| {
+                let range = mention.range.as_ref()?;
+                if !body.is_char_boundary(range.start as usize)
+                    || !body.is_char_boundary(range.end as usize)
+                {
+                    return None;
+                }
+                Some(channel_message_mention::ActiveModel {
+                    message_id: ActiveValue::Set(message_id),
+                    start_offset: ActiveValue::Set(range.start as i32),
+                    end_offset: ActiveValue::Set(range.end as i32),
+                    user_id: ActiveValue::Set(UserId::from_proto(mention.user_id)),
+                })
+            })
+            .collect::<Vec<_>>())
+    }
+
     /// Creates a new channel message.
     #[allow(clippy::too_many_arguments)]
     pub async fn create_channel_message(
@@ -249,6 +277,7 @@ impl Database {
                 nonce: ActiveValue::Set(Uuid::from_u128(nonce)),
                 id: ActiveValue::NotSet,
                 reply_to_message_id: ActiveValue::Set(reply_to_message_id),
+                edited_at: ActiveValue::NotSet,
             })
             .on_conflict(
                 OnConflict::columns([
@@ -270,23 +299,7 @@ impl Database {
                     let mentioned_user_ids =
                         mentions.iter().map(|m| m.user_id).collect::<HashSet<_>>();
 
-                    let mentions = mentions
-                        .iter()
-                        .filter_map(|mention| {
-                            let range = mention.range.as_ref()?;
-                            if !body.is_char_boundary(range.start as usize)
-                                || !body.is_char_boundary(range.end as usize)
-                            {
-                                return None;
-                            }
-                            Some(channel_message_mention::ActiveModel {
-                                message_id: ActiveValue::Set(message_id),
-                                start_offset: ActiveValue::Set(range.start as i32),
-                                end_offset: ActiveValue::Set(range.end as i32),
-                                user_id: ActiveValue::Set(UserId::from_proto(mention.user_id)),
-                            })
-                        })
-                        .collect::<Vec<_>>();
+                    let mentions = self.format_mentions_to_entities(message_id, body, mentions)?;
                     if !mentions.is_empty() {
                         channel_message_mention::Entity::insert_many(mentions)
                             .exec(&*tx)
@@ -522,4 +535,131 @@ impl Database {
         })
         .await
     }
+
+    /// Updates the channel message with the given ID, body and timestamp(edited_at).
+    pub async fn update_channel_message(
+        &self,
+        channel_id: ChannelId,
+        message_id: MessageId,
+        user_id: UserId,
+        body: &str,
+        mentions: &[proto::ChatMention],
+        edited_at: OffsetDateTime,
+    ) -> Result<UpdatedChannelMessage> {
+        self.transaction(|tx| async move {
+            let channel = self.get_channel_internal(channel_id, &tx).await?;
+            self.check_user_is_channel_participant(&channel, user_id, &tx)
+                .await?;
+
+            let mut rows = channel_chat_participant::Entity::find()
+                .filter(channel_chat_participant::Column::ChannelId.eq(channel_id))
+                .stream(&*tx)
+                .await?;
+
+            let mut is_participant = false;
+            let mut participant_connection_ids = Vec::new();
+            let mut participant_user_ids = Vec::new();
+            while let Some(row) = rows.next().await {
+                let row = row?;
+                if row.user_id == user_id {
+                    is_participant = true;
+                }
+                participant_user_ids.push(row.user_id);
+                participant_connection_ids.push(row.connection());
+            }
+            drop(rows);
+
+            if !is_participant {
+                Err(anyhow!("not a chat participant"))?;
+            }
+
+            let channel_message = channel_message::Entity::find_by_id(message_id)
+                .filter(channel_message::Column::SenderId.eq(user_id))
+                .one(&*tx)
+                .await?;
+
+            let Some(channel_message) = channel_message else {
+                Err(anyhow!("Channel message not found"))?
+            };
+
+            let edited_at = edited_at.to_offset(time::UtcOffset::UTC);
+            let edited_at = time::PrimitiveDateTime::new(edited_at.date(), edited_at.time());
+
+            let updated_message = channel_message::ActiveModel {
+                body: ActiveValue::Set(body.to_string()),
+                edited_at: ActiveValue::Set(Some(edited_at)),
+                reply_to_message_id: ActiveValue::Unchanged(channel_message.reply_to_message_id),
+                id: ActiveValue::Unchanged(message_id),
+                channel_id: ActiveValue::Unchanged(channel_id),
+                sender_id: ActiveValue::Unchanged(user_id),
+                sent_at: ActiveValue::Unchanged(channel_message.sent_at),
+                nonce: ActiveValue::Unchanged(channel_message.nonce),
+            };
+
+            let result = channel_message::Entity::update_many()
+                .set(updated_message)
+                .filter(channel_message::Column::Id.eq(message_id))
+                .filter(channel_message::Column::SenderId.eq(user_id))
+                .exec(&*tx)
+                .await?;
+            if result.rows_affected == 0 {
+                return Err(anyhow!(
+                    "Attempted to edit a message (id: {message_id}) which does not exist anymore."
+                ))?;
+            }
+
+            // we have to fetch the old mentions,
+            // so we don't send a notification when the message has been edited that you are mentioned in
+            let old_mentions = channel_message_mention::Entity::find()
+                .filter(channel_message_mention::Column::MessageId.eq(message_id))
+                .all(&*tx)
+                .await?;
+
+            // remove all existing mentions
+            channel_message_mention::Entity::delete_many()
+                .filter(channel_message_mention::Column::MessageId.eq(message_id))
+                .exec(&*tx)
+                .await?;
+
+            let new_mentions = self.format_mentions_to_entities(message_id, body, mentions)?;
+            if !new_mentions.is_empty() {
+                // insert new mentions
+                channel_message_mention::Entity::insert_many(new_mentions)
+                    .exec(&*tx)
+                    .await?;
+            }
+
+            let mut mentioned_user_ids = mentions.iter().map(|m| m.user_id).collect::<HashSet<_>>();
+            // Filter out users that were mentioned before
+            for mention in old_mentions {
+                mentioned_user_ids.remove(&mention.user_id.to_proto());
+            }
+
+            let mut notifications = Vec::new();
+            for mentioned_user in mentioned_user_ids {
+                notifications.extend(
+                    self.create_notification(
+                        UserId::from_proto(mentioned_user),
+                        rpc::Notification::ChannelMessageMention {
+                            message_id: message_id.to_proto(),
+                            sender_id: user_id.to_proto(),
+                            channel_id: channel_id.to_proto(),
+                        },
+                        false,
+                        &tx,
+                    )
+                    .await?,
+                );
+            }
+
+            Ok(UpdatedChannelMessage {
+                message_id,
+                participant_connection_ids,
+                notifications,
+                reply_to_message_id: channel_message.reply_to_message_id,
+                timestamp: channel_message.sent_at,
+            })
+        })
+        .await
+    }
 }

crates/collab/src/db/tables/channel_message.rs

@@ -11,6 +11,7 @@ pub struct Model {
     pub sender_id: UserId,
     pub body: String,
     pub sent_at: PrimitiveDateTime,
+    pub edited_at: Option<PrimitiveDateTime>,
     pub nonce: Uuid,
     pub reply_to_message_id: Option<MessageId>,
 }

crates/collab/src/rpc.rs

@@ -6,7 +6,7 @@ use crate::{
         self, BufferId, Channel, ChannelId, ChannelRole, ChannelsForUser, CreatedChannelMessage,
         Database, InviteMemberResult, MembershipUpdated, MessageId, NotificationId, Project,
         ProjectId, RemoveChannelMemberResult, ReplicaId, RespondToChannelInvite, RoomId, ServerId,
-        User, UserId,
+        UpdatedChannelMessage, User, UserId,
     },
     executor::Executor,
     AppState, Error, RateLimit, RateLimiter, Result,
@@ -283,6 +283,7 @@ impl Server {
             .add_message_handler(leave_channel_chat)
             .add_request_handler(send_channel_message)
             .add_request_handler(remove_channel_message)
+            .add_request_handler(update_channel_message)
             .add_request_handler(get_channel_messages)
             .add_request_handler(get_channel_messages_by_id)
             .add_request_handler(get_notifications)
@@ -3191,6 +3192,7 @@ async fn send_channel_message(
             },
         )
         .await?;
+
     let message = proto::ChannelMessage {
         sender_id: session.user_id.to_proto(),
         id: message_id.to_proto(),
@@ -3199,6 +3201,7 @@ async fn send_channel_message(
         timestamp: timestamp.unix_timestamp() as u64,
         nonce: Some(nonce),
         reply_to_message_id: request.reply_to_message_id,
+        edited_at: None,
     };
     broadcast(
         Some(session.connection_id),
@@ -3261,6 +3264,71 @@ async fn remove_channel_message(
     Ok(())
 }
 
+async fn update_channel_message(
+    request: proto::UpdateChannelMessage,
+    response: Response<proto::UpdateChannelMessage>,
+    session: Session,
+) -> Result<()> {
+    let channel_id = ChannelId::from_proto(request.channel_id);
+    let message_id = MessageId::from_proto(request.message_id);
+    let updated_at = OffsetDateTime::now_utc();
+    let UpdatedChannelMessage {
+        message_id,
+        participant_connection_ids,
+        notifications,
+        reply_to_message_id,
+        timestamp,
+    } = session
+        .db()
+        .await
+        .update_channel_message(
+            channel_id,
+            message_id,
+            session.user_id,
+            request.body.as_str(),
+            &request.mentions,
+            updated_at,
+        )
+        .await?;
+
+    let nonce = request
+        .nonce
+        .clone()
+        .ok_or_else(|| anyhow!("nonce can't be blank"))?;
+
+    let message = proto::ChannelMessage {
+        sender_id: session.user_id.to_proto(),
+        id: message_id.to_proto(),
+        body: request.body.clone(),
+        mentions: request.mentions.clone(),
+        timestamp: timestamp.assume_utc().unix_timestamp() as u64,
+        nonce: Some(nonce),
+        reply_to_message_id: reply_to_message_id.map(|id| id.to_proto()),
+        edited_at: Some(updated_at.unix_timestamp() as u64),
+    };
+
+    response.send(proto::Ack {})?;
+
+    let pool = &*session.connection_pool().await;
+    broadcast(
+        Some(session.connection_id),
+        participant_connection_ids,
+        |connection| {
+            session.peer.send(
+                connection,
+                proto::ChannelMessageUpdate {
+                    channel_id: channel_id.to_proto(),
+                    message: Some(message.clone()),
+                },
+            )
+        },
+    );
+
+    send_notifications(pool, &session.peer, notifications);
+
+    Ok(())
+}
+
 /// Mark a channel message as read
 async fn acknowledge_channel_message(
     request: proto::AckChannelMessage,

crates/collab/src/tests/channel_message_tests.rs

@@ -466,3 +466,136 @@ async fn test_chat_replies(cx_a: &mut TestAppContext, cx_b: &mut TestAppContext)
         )
     });
 }
+
+#[gpui::test]
+async fn test_chat_editing(cx_a: &mut TestAppContext, cx_b: &mut TestAppContext) {
+    let mut server = TestServer::start(cx_a.executor()).await;
+    let client_a = server.create_client(cx_a, "user_a").await;
+    let client_b = server.create_client(cx_b, "user_b").await;
+
+    let channel_id = server
+        .make_channel(
+            "the-channel",
+            None,
+            (&client_a, cx_a),
+            &mut [(&client_b, cx_b)],
+        )
+        .await;
+
+    // Client A sends a message, client B should see that there is a new message.
+    let channel_chat_a = client_a
+        .channel_store()
+        .update(cx_a, |store, cx| store.open_channel_chat(channel_id, cx))
+        .await
+        .unwrap();
+
+    let channel_chat_b = client_b
+        .channel_store()
+        .update(cx_b, |store, cx| store.open_channel_chat(channel_id, cx))
+        .await
+        .unwrap();
+
+    let msg_id = channel_chat_a
+        .update(cx_a, |c, cx| {
+            c.send_message(
+                MessageParams {
+                    text: "Initial message".into(),
+                    reply_to_message_id: None,
+                    mentions: Vec::new(),
+                },
+                cx,
+            )
+            .unwrap()
+        })
+        .await
+        .unwrap();
+
+    cx_a.run_until_parked();
+
+    channel_chat_a
+        .update(cx_a, |c, cx| {
+            c.update_message(
+                msg_id,
+                MessageParams {
+                    text: "Updated body".into(),
+                    reply_to_message_id: None,
+                    mentions: Vec::new(),
+                },
+                cx,
+            )
+            .unwrap()
+        })
+        .await
+        .unwrap();
+
+    cx_a.run_until_parked();
+    cx_b.run_until_parked();
+
+    channel_chat_a.update(cx_a, |channel_chat, _| {
+        let update_message = channel_chat.find_loaded_message(msg_id).unwrap();
+
+        assert_eq!(update_message.body, "Updated body");
+        assert_eq!(update_message.mentions, Vec::new());
+    });
+    channel_chat_b.update(cx_b, |channel_chat, _| {
+        let update_message = channel_chat.find_loaded_message(msg_id).unwrap();
+
+        assert_eq!(update_message.body, "Updated body");
+        assert_eq!(update_message.mentions, Vec::new());
+    });
+
+    // test mentions are updated correctly
+
+    client_b.notification_store().read_with(cx_b, |store, _| {
+        assert_eq!(store.notification_count(), 1);
+        let entry = store.notification_at(0).unwrap();
+        assert!(matches!(
+            entry.notification,
+            Notification::ChannelInvitation { .. }
+        ),);
+    });
+
+    channel_chat_a
+        .update(cx_a, |c, cx| {
+            c.update_message(
+                msg_id,
+                MessageParams {
+                    text: "Updated body including a mention for @user_b".into(),
+                    reply_to_message_id: None,
+                    mentions: vec![(37..45, client_b.id())],
+                },
+                cx,
+            )
+            .unwrap()
+        })
+        .await
+        .unwrap();
+
+    cx_a.run_until_parked();
+    cx_b.run_until_parked();
+
+    channel_chat_a.update(cx_a, |channel_chat, _| {
+        assert_eq!(
+            channel_chat.find_loaded_message(msg_id).unwrap().body,
+            "Updated body including a mention for @user_b",
+        )
+    });
+    channel_chat_b.update(cx_b, |channel_chat, _| {
+        assert_eq!(
+            channel_chat.find_loaded_message(msg_id).unwrap().body,
+            "Updated body including a mention for @user_b",
+        )
+    });
+    client_b.notification_store().read_with(cx_b, |store, _| {
+        assert_eq!(store.notification_count(), 2);
+        let entry = store.notification_at(0).unwrap();
+        assert_eq!(
+            entry.notification,
+            Notification::ChannelMessageMention {
+                message_id: msg_id,
+                sender_id: client_a.id(),
+                channel_id: channel_id.0,
+            }
+        );
+    });
+}

crates/collab_ui/src/chat_panel.rs

@@ -5,18 +5,18 @@ use channel::{ChannelChat, ChannelChatEvent, ChannelMessage, ChannelMessageId, C
 use client::{ChannelId, Client};
 use collections::HashMap;
 use db::kvp::KEY_VALUE_STORE;
-use editor::Editor;
+use editor::{actions, Editor};
 use gpui::{
     actions, div, list, prelude::*, px, Action, AppContext, AsyncWindowContext, ClipboardItem,
     CursorStyle, DismissEvent, ElementId, EventEmitter, FocusHandle, FocusableView, FontWeight,
-    ListOffset, ListScrollEvent, ListState, Model, Render, Subscription, Task, View, ViewContext,
-    VisualContext, WeakView,
+    HighlightStyle, ListOffset, ListScrollEvent, ListState, Model, Render, Stateful, Subscription,
+    Task, View, ViewContext, VisualContext, WeakView,
 };
 use language::LanguageRegistry;
 use menu::Confirm;
 use message_editor::MessageEditor;
 use project::Fs;
-use rich_text::RichText;
+use rich_text::{Highlight, RichText};
 use serde::{Deserialize, Serialize};
 use settings::Settings;
 use std::{sync::Arc, time::Duration};
@@ -64,7 +64,6 @@ pub struct ChatPanel {
     open_context_menu: Option<(u64, Subscription)>,
     highlighted_message: Option<(u64, Task<()>)>,
     last_acknowledged_message_id: Option<u64>,
-    selected_message_to_reply_id: Option<u64>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -72,7 +71,7 @@ struct SerializedChatPanel {
     width: Option<Pixels>,
 }
 
-actions!(chat_panel, [ToggleFocus, CloseReplyPreview]);
+actions!(chat_panel, [ToggleFocus]);
 
 impl ChatPanel {
     pub fn new(workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) -> View<Self> {
@@ -129,7 +128,6 @@ impl ChatPanel {
                 open_context_menu: None,
                 highlighted_message: None,
                 last_acknowledged_message_id: None,
-                selected_message_to_reply_id: None,
             };
 
             if let Some(channel_id) = ActiveCall::global(cx)
@@ -268,6 +266,13 @@ impl ChatPanel {
                     self.acknowledge_last_message(cx);
                 }
             }
+            ChannelChatEvent::UpdateMessage {
+                message_id,
+                message_ix,
+            } => {
+                self.message_list.splice(*message_ix..*message_ix + 1, 1);
+                self.markdown_data.remove(message_id);
+            }
             ChannelChatEvent::NewMessage {
                 channel_id,
                 message_id,
@@ -349,6 +354,7 @@ impl ChatPanel {
                 .px_0p5()
                 .gap_x_1()
                 .rounded_md()
+                .overflow_hidden()
                 .hover(|style| style.bg(cx.theme().colors().element_background))
                 .child(Icon::new(IconName::ReplyArrowRight).color(Color::Muted))
                 .child(Avatar::new(user_being_replied_to.avatar_uri.clone()).size(rems(0.7)))
@@ -413,6 +419,7 @@ impl ChatPanel {
 
         let belongs_to_user = Some(message.sender.id) == self.client.user_id();
         let can_delete_message = belongs_to_user || is_admin;
+        let can_edit_message = belongs_to_user;
 
         let element_id: ElementId = match message.id {
             ChannelMessageId::Saved(id) => ("saved-message", id).into(),
@@ -449,6 +456,8 @@ impl ChatPanel {
             cx.theme().colors().panel_background
         };
 
+        let reply_to_message_id = self.message_editor.read(cx).reply_to_message_id();
+
         v_flex()
             .w_full()
             .relative()
@@ -462,7 +471,7 @@ impl ChatPanel {
                     .overflow_hidden()
                     .px_1p5()
                     .py_0p5()
-                    .when_some(self.selected_message_to_reply_id, |el, reply_id| {
+                    .when_some(reply_to_message_id, |el, reply_id| {
                         el.when_some(message_id, |el, message_id| {
                             el.when(reply_id == message_id, |el| {
                                 el.bg(cx.theme().colors().element_selected)
@@ -559,7 +568,7 @@ impl ChatPanel {
                 },
             )
             .child(
-                self.render_popover_buttons(&cx, message_id, can_delete_message)
+                self.render_popover_buttons(&cx, message_id, can_delete_message, can_edit_message)
                     .neg_mt_2p5(),
             )
     }
@@ -571,75 +580,102 @@ impl ChatPanel {
         }
     }
 
+    fn render_popover_button(&self, cx: &ViewContext<Self>, child: Stateful<Div>) -> Div {
+        div()
+            .w_6()
+            .bg(cx.theme().colors().element_background)
+            .hover(|style| style.bg(cx.theme().colors().element_hover).rounded_md())
+            .child(child)
+    }
+
     fn render_popover_buttons(
         &self,
         cx: &ViewContext<Self>,
         message_id: Option<u64>,
         can_delete_message: bool,
+        can_edit_message: bool,
     ) -> Div {
-        div()
+        h_flex()
             .absolute()
-            .child(
-                div()
-                    .absolute()
-                    .right_8()
-                    .w_6()
-                    .rounded_tl_md()
-                    .rounded_bl_md()
-                    .border_l_1()
-                    .border_t_1()
-                    .border_b_1()
+            .right_2()
+            .overflow_hidden()
+            .rounded_md()
             .border_color(cx.theme().colors().element_selected)
-                    .bg(cx.theme().colors().element_background)
-                    .hover(|style| style.bg(cx.theme().colors().element_hover))
+            .border_1()
             .when(!self.has_open_menu(message_id), |el| {
                 el.visible_on_hover("")
             })
+            .bg(cx.theme().colors().element_background)
             .when_some(message_id, |el, message_id| {
                 el.child(
+                    self.render_popover_button(
+                        cx,
                         div()
                             .id("reply")
                             .child(
-                                    IconButton::new(
-                                        ("reply", message_id),
-                                        IconName::ReplyArrowLeft,
-                                    )
-                                    .on_click(cx.listener(
-                                        move |this, _, cx| {
-                                            this.selected_message_to_reply_id = Some(message_id);
+                                IconButton::new(("reply", message_id), IconName::ReplyArrowRight)
+                                    .on_click(cx.listener(move |this, _, cx| {
                                         this.message_editor.update(cx, |editor, cx| {
                                             editor.set_reply_to_message_id(message_id);
                                             editor.focus_handle(cx).focus(cx);
                                         })
-                                        },
-                                    )),
+                                    })),
                             )
                             .tooltip(|cx| Tooltip::text("Reply", cx)),
+                    ),
                 )
-                    }),
-            )
-            .child(
+            })
+            .when_some(message_id, |el, message_id| {
+                el.when(can_edit_message, |el| {
+                    el.child(
+                        self.render_popover_button(
+                            cx,
                             div()
-                    .absolute()
-                    .right_2()
-                    .w_6()
-                    .rounded_tr_md()
-                    .rounded_br_md()
-                    .border_r_1()
-                    .border_t_1()
-                    .border_b_1()
-                    .border_color(cx.theme().colors().element_selected)
-                    .bg(cx.theme().colors().element_background)
-                    .hover(|style| style.bg(cx.theme().colors().element_hover))
-                    .when(!self.has_open_menu(message_id), |el| {
-                        el.visible_on_hover("")
+                                .id("edit")
+                                .child(
+                                    IconButton::new(("edit", message_id), IconName::Pencil)
+                                        .on_click(cx.listener(move |this, _, cx| {
+                                            this.message_editor.update(cx, |editor, cx| {
+                                                let message = this
+                                                    .active_chat()
+                                                    .and_then(|active_chat| {
+                                                        active_chat
+                                                            .read(cx)
+                                                            .find_loaded_message(message_id)
+                                                    })
+                                                    .cloned();
+
+                                                if let Some(message) = message {
+                                                    let buffer = editor
+                                                        .editor
+                                                        .read(cx)
+                                                        .buffer()
+                                                        .read(cx)
+                                                        .as_singleton()
+                                                        .expect("message editor must be singleton");
+
+                                                    buffer.update(cx, |buffer, cx| {
+                                                        buffer.set_text(message.body.clone(), cx)
+                                                    });
+
+                                                    editor.set_edit_message_id(message_id);
+                                                    editor.focus_handle(cx).focus(cx);
+                                                }
+                                            })
+                                        })),
+                                )
+                                .tooltip(|cx| Tooltip::text("Edit", cx)),
+                        ),
+                    )
+                })
             })
             .when_some(message_id, |el, message_id| {
                 let this = cx.view().clone();
 
                 el.child(
+                    self.render_popover_button(
+                        cx,
                         div()
-                                .id("more")
                             .child(
                                 popover_menu(("menu", message_id))
                                     .trigger(IconButton::new(
@@ -655,10 +691,11 @@ impl ChatPanel {
                                         ))
                                     }),
                             )
+                            .id("more")
                             .tooltip(|cx| Tooltip::text("More", cx)),
+                    ),
                 )
-                    }),
-            )
+            })
     }
 
     fn render_message_menu(
@@ -670,18 +707,6 @@ impl ChatPanel {
         let menu = {
             ContextMenu::build(cx, move |menu, cx| {
                 menu.entry(
-                    "Reply to message",
-                    None,
-                    cx.handler_for(&this, move |this, cx| {
-                        this.selected_message_to_reply_id = Some(message_id);
-
-                        this.message_editor.update(cx, |editor, cx| {
-                            editor.set_reply_to_message_id(message_id);
-                            editor.focus_handle(cx).focus(cx);
-                        })
-                    }),
-                )
-                .entry(
                     "Copy message text",
                     None,
                     cx.handler_for(&this, move |this, cx| {
@@ -693,7 +718,7 @@ impl ChatPanel {
                         }
                     }),
                 )
-                .when(can_delete_message, move |menu| {
+                .when(can_delete_message, |menu| {
                     menu.entry(
                         "Delete message",
                         None,
@@ -725,17 +750,46 @@ impl ChatPanel {
             })
             .collect::<Vec<_>>();
 
-        rich_text::render_rich_text(message.body.clone(), &mentions, language_registry, None)
+        const MESSAGE_UPDATED: &str = " (edited)";
+
+        let mut body = message.body.clone();
+
+        if message.edited_at.is_some() {
+            body.push_str(MESSAGE_UPDATED);
+        }
+
+        let mut rich_text = rich_text::render_rich_text(body, &mentions, language_registry, None);
+
+        if message.edited_at.is_some() {
+            rich_text.highlights.push((
+                message.body.len()..(message.body.len() + MESSAGE_UPDATED.len()),
+                Highlight::Highlight(HighlightStyle {
+                    fade_out: Some(0.8),
+                    ..Default::default()
+                }),
+            ));
+        }
+        rich_text
     }
 
     fn send(&mut self, _: &Confirm, cx: &mut ViewContext<Self>) {
-        self.selected_message_to_reply_id = None;
-
         if let Some((chat, _)) = self.active_chat.as_ref() {
             let message = self
                 .message_editor
                 .update(cx, |editor, cx| editor.take_message(cx));
 
+            if let Some(id) = self.message_editor.read(cx).edit_message_id() {
+                self.message_editor.update(cx, |editor, _| {
+                    editor.clear_edit_message_id();
+                });
+
+                if let Some(task) = chat
+                    .update(cx, |chat, cx| chat.update_message(id, message, cx))
+                    .log_err()
+                {
+                    task.detach();
+                }
+            } else {
                 if let Some(task) = chat
                     .update(cx, |chat, cx| chat.send_message(message, cx))
                     .log_err()
@@ -744,6 +798,7 @@ impl ChatPanel {
                 }
             }
         }
+    }
 
     fn remove_message(&mut self, id: u64, cx: &mut ViewContext<Self>) {
         if let Some((chat, _)) = self.active_chat.as_ref() {
@@ -825,16 +880,39 @@ impl ChatPanel {
         })
     }
 
-    fn close_reply_preview(&mut self, _: &CloseReplyPreview, cx: &mut ViewContext<Self>) {
-        self.selected_message_to_reply_id = None;
+    fn close_reply_preview(&mut self, cx: &mut ViewContext<Self>) {
         self.message_editor
             .update(cx, |editor, _| editor.clear_reply_to_message_id());
     }
+
+    fn cancel_edit_message(&mut self, cx: &mut ViewContext<Self>) {
+        self.message_editor.update(cx, |editor, cx| {
+            // only clear the editor input if we were editing a message
+            if editor.edit_message_id().is_none() {
+                return;
+            }
+
+            editor.clear_edit_message_id();
+
+            let buffer = editor
+                .editor
+                .read(cx)
+                .buffer()
+                .read(cx)
+                .as_singleton()
+                .expect("message editor must be singleton");
+
+            buffer.update(cx, |buffer, cx| buffer.set_text("", cx));
+        });
+    }
 }
 
 impl Render for ChatPanel {
     fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
-        let reply_to_message_id = self.message_editor.read(cx).reply_to_message_id();
+        let message_editor = self.message_editor.read(cx);
+
+        let reply_to_message_id = message_editor.reply_to_message_id();
+        let edit_message_id = message_editor.edit_message_id();
 
         v_flex()
             .key_context("ChatPanel")
@@ -890,13 +968,36 @@ impl Render for ChatPanel {
                     )
                 }
             }))
+            .when(!self.is_scrolled_to_bottom, |el| {
+                el.child(div().border_t_1().border_color(cx.theme().colors().border))
+            })
+            .when_some(edit_message_id, |el, _| {
+                el.child(
+                    h_flex()
+                        .px_2()
+                        .text_ui_xs()
+                        .justify_between()
+                        .border_t_1()
+                        .border_color(cx.theme().colors().border)
+                        .bg(cx.theme().colors().background)
+                        .child("Editing message")
+                        .child(
+                            IconButton::new("cancel-edit-message", IconName::Close)
+                                .shape(ui::IconButtonShape::Square)
+                                .tooltip(|cx| Tooltip::text("Cancel edit message", cx))
+                                .on_click(cx.listener(move |this, _, cx| {
+                                    this.cancel_edit_message(cx);
+                                })),
+                        ),
+                )
+            })
             .when_some(reply_to_message_id, |el, reply_to_message_id| {
                 let reply_message = self
                     .active_chat()
                     .and_then(|active_chat| {
-                        active_chat.read(cx).messages().iter().find(|message| {
-                            message.id == ChannelMessageId::Saved(reply_to_message_id)
-                        })
+                        active_chat
+                            .read(cx)
+                            .find_loaded_message(reply_to_message_id)
                     })
                     .cloned();
 
@@ -932,13 +1033,9 @@ impl Render for ChatPanel {
                             .child(
                                 IconButton::new("close-reply-preview", IconName::Close)
                                     .shape(ui::IconButtonShape::Square)
-                                    .tooltip(|cx| {
-                                        Tooltip::for_action("Close reply", &CloseReplyPreview, cx)
-                                    })
+                                    .tooltip(|cx| Tooltip::text("Close reply", cx))
                                     .on_click(cx.listener(move |this, _, cx| {
-                                        this.selected_message_to_reply_id = None;
-
-                                        cx.dispatch_action(CloseReplyPreview.boxed_clone())
+                                        this.close_reply_preview(cx);
                                     })),
                             ),
                     )
@@ -947,13 +1044,11 @@ impl Render for ChatPanel {
             .children(
                 Some(
                     h_flex()
-                        .key_context("MessageEditor")
-                        .on_action(cx.listener(ChatPanel::close_reply_preview))
-                        .when(
-                            !self.is_scrolled_to_bottom && reply_to_message_id.is_none(),
-                            |el| el.border_t_1().border_color(cx.theme().colors().border),
-                        )
                         .p_2()
+                        .on_action(cx.listener(|this, _: &actions::Cancel, cx| {
+                            this.cancel_edit_message(cx);
+                            this.close_reply_preview(cx);
+                        }))
                         .map(|el| el.child(self.message_editor.clone())),
                 )
                 .filter(|_| self.active_chat.is_some()),
@@ -1056,6 +1151,7 @@ mod tests {
             nonce: 5,
             mentions: vec![(ranges[0].clone(), 101), (ranges[1].clone(), 102)],
             reply_to_message_id: None,
+            edited_at: None,
         };
 
         let message = ChatPanel::render_markdown_with_mentions(&language_registry, 102, &message);
@@ -1103,6 +1199,7 @@ mod tests {
             nonce: 5,
             mentions: Vec::new(),
             reply_to_message_id: None,
+            edited_at: None,
         };
 
         let message = ChatPanel::render_markdown_with_mentions(&language_registry, 102, &message);
@@ -1143,6 +1240,7 @@ mod tests {
             nonce: 5,
             mentions: Vec::new(),
             reply_to_message_id: None,
+            edited_at: None,
         };
 
         let message = ChatPanel::render_markdown_with_mentions(&language_registry, 102, &message);

crates/collab_ui/src/chat_panel/message_editor.rs

@@ -37,6 +37,7 @@ pub struct MessageEditor {
     mentions_task: Option<Task<()>>,
     channel_id: Option<ChannelId>,
     reply_to_message_id: Option<u64>,
+    edit_message_id: Option<u64>,
 }
 
 struct MessageEditorCompletionProvider(WeakView<MessageEditor>);
@@ -131,6 +132,7 @@ impl MessageEditor {
             mentions: Vec::new(),
             mentions_task: None,
             reply_to_message_id: None,
+            edit_message_id: None,
         }
     }
 
@@ -146,6 +148,18 @@ impl MessageEditor {
         self.reply_to_message_id = None;
     }
 
+    pub fn edit_message_id(&self) -> Option<u64> {
+        self.edit_message_id
+    }
+
+    pub fn set_edit_message_id(&mut self, edit_message_id: u64) {
+        self.edit_message_id = Some(edit_message_id);
+    }
+
+    pub fn clear_edit_message_id(&mut self) {
+        self.edit_message_id = None;
+    }
+
     pub fn set_channel(
         &mut self,
         channel_id: ChannelId,

crates/rpc/proto/zed.proto

@@ -203,7 +203,9 @@ message Envelope {
         CompleteWithLanguageModel complete_with_language_model = 166;
         LanguageModelResponse language_model_response = 167;
         CountTokensWithLanguageModel count_tokens_with_language_model = 168;
-        CountTokensResponse count_tokens_response = 169; // current max
+        CountTokensResponse count_tokens_response = 169;
+        UpdateChannelMessage update_channel_message = 170;
+        ChannelMessageUpdate channel_message_update = 171;  // current max
     }
 
     reserved 158 to 161;
@@ -1184,6 +1186,14 @@ message RemoveChannelMessage {
     uint64 message_id = 2;
 }
 
+message UpdateChannelMessage {
+    uint64 channel_id = 1;
+    uint64 message_id = 2;
+    Nonce nonce = 4;
+    string body = 5;
+    repeated ChatMention mentions = 6;
+}
+
 message AckChannelMessage {
     uint64 channel_id = 1;
     uint64 message_id = 2;
@@ -1198,6 +1208,11 @@ message ChannelMessageSent {
     ChannelMessage message = 2;
 }
 
+message ChannelMessageUpdate {
+    uint64 channel_id = 1;
+    ChannelMessage message = 2;
+}
+
 message GetChannelMessages {
     uint64 channel_id = 1;
     uint64 before_message_id = 2;
@@ -1229,6 +1244,7 @@ message ChannelMessage {
     Nonce nonce = 5;
     repeated ChatMention mentions = 6;
     optional uint64 reply_to_message_id = 7;
+    optional uint64 edited_at = 8;
 }
 
 message ChatMention {

crates/rpc/src/proto.rs

@@ -149,6 +149,7 @@ messages!(
     (CallCanceled, Foreground),
     (CancelCall, Foreground),
     (ChannelMessageSent, Foreground),
+    (ChannelMessageUpdate, Foreground),
     (CompleteWithLanguageModel, Background),
     (CopyProjectEntry, Foreground),
     (CountTokensWithLanguageModel, Background),
@@ -244,6 +245,7 @@ messages!(
     (ReloadBuffersResponse, Foreground),
     (RemoveChannelMember, Foreground),
     (RemoveChannelMessage, Foreground),
+    (UpdateChannelMessage, Foreground),
     (RemoveContact, Foreground),
     (RemoveProjectCollaborator, Foreground),
     (RenameChannel, Foreground),
@@ -358,6 +360,7 @@ request_messages!(
     (ReloadBuffers, ReloadBuffersResponse),
     (RemoveChannelMember, Ack),
     (RemoveChannelMessage, Ack),
+    (UpdateChannelMessage, Ack),
     (RemoveContact, Ack),
     (RenameChannel, RenameChannelResponse),
     (RenameProjectEntry, ProjectEntryResponse),
@@ -442,7 +445,9 @@ entity_messages!(
 entity_messages!(
     {channel_id, Channel},
     ChannelMessageSent,
+    ChannelMessageUpdate,
     RemoveChannelMessage,
+    UpdateChannelMessage,
     UpdateChannelBuffer,
     UpdateChannelBufferCollaborators,
 );

crates/ui/src/components/icon.rs

@@ -93,6 +93,7 @@ pub enum IconName {
     Option,
     PageDown,
     PageUp,
+    Pencil,
     Play,
     Plus,
     Public,
@@ -188,6 +189,7 @@ impl IconName {
             IconName::Option => "icons/option.svg",
             IconName::PageDown => "icons/page_down.svg",
             IconName::PageUp => "icons/page_up.svg",
+            IconName::Pencil => "icons/pencil.svg",
             IconName::Play => "icons/play.svg",
             IconName::Plus => "icons/plus.svg",
             IconName::Public => "icons/public.svg",