fix: calculate new first unread message id only if the last_read valu…

…e changed
GetStream · Jan 19, 2024 · 4cd5698 · 4cd5698
1 parent a561748
commit 4cd5698
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Showing 2 changed files with 42 additions and 2 deletions.
diff --git a/src/channel.ts b/src/channel.ts
@@ -1528,15 +1528,19 @@ export class Channel<StreamChatGenerics extends ExtendableGenerics = DefaultGene
     // apply read state if part of the state
     if (state.read) {
       for (const read of state.read) {
-        this.state.read[read.user.id] = {
+        const previousReadState = this.state.read[read.user.id];
+        const newReadState = {
           last_read: new Date(read.last_read),
           last_read_message_id: read.last_read_message_id,
           unread_messages: read.unread_messages ?? 0,
           user: read.user,
         };
+        this.state.read[read.user.id] = newReadState;
 
         if (read.user.id === user?.id) {
-          if (this.state.read[user.id].last_read) {
+          const lastReadChanged =
+            newReadState.last_read && newReadState.last_read.getTime() !== previousReadState?.last_read.getTime();
+          if (lastReadChanged) {
             for (let i = 0; i < messageSet.messages.length; i++) {
               const msg = messageSet.messages[i];
               const isOwnMsg = msg.user?.id === user.id;
@@ -1545,6 +1549,8 @@ export class Channel<StreamChatGenerics extends ExtendableGenerics = DefaultGene
               this.state.read[read.user.id].first_unread_message_id = msg.id;
               break;
             }
+          } else {
+            this.state.read[read.user.id].first_unread_message_id = previousReadState.first_unread_message_id;
           }
 
           this.state.unreadCount = this.state.read[read.user.id].unread_messages;

diff --git a/test/unit/channel.js b/test/unit/channel.js
@@ -1259,4 +1259,38 @@ describe('Channel _initializeState', () => {
 		channel._initializeState(state);
 		expect(channel.state.read[client.user.id].first_unread_message_id).to.be.undefined;
 	});
+
+	it('should update first unread message id if last_read has not changed', async () => {
+		const createdAtMsg3 = new Date();
+		const createdAtMsg2 = new Date(new Date(createdAtMsg3).getTime() - 500);
+		const createdAtMsg1 = new Date(new Date(createdAtMsg3).getTime() - 1000);
+		const messages = [
+			generateMsg({ date: createdAtMsg1.toISOString() }),
+			generateMsg({ date: createdAtMsg2.toISOString() }),
+			generateMsg({ date: createdAtMsg3.toISOString() }),
+		];
+		let newState = { messages, read: [{ last_read: createdAtMsg1.toISOString(), user: client.user }] };
+		channel._initializeState(newState);
+		expect(channel.state.read[client.user.id].first_unread_message_id).to.be.equal(messages[1].id);
+		newState = { messages, read: [{ last_read: createdAtMsg2.toISOString(), user: client.user }] };
+		channel._initializeState(newState);
+		expect(channel.state.read[client.user.id].first_unread_message_id).to.be.equal(messages[2].id);
+	});
+
+	it('should not update first unread message id if last_read has not changed', async () => {
+		const createdAtMsg3 = new Date();
+		const createdAtMsg2 = new Date(new Date(createdAtMsg3).getTime() - 500);
+		const createdAtMsg1 = new Date(new Date(createdAtMsg3).getTime() - 1000);
+		const messages = [
+			generateMsg({ date: createdAtMsg1.toISOString() }),
+			generateMsg({ date: createdAtMsg2.toISOString() }),
+			generateMsg({ date: createdAtMsg3.toISOString() }),
+		];
+		let newState = { messages, read: [{ last_read: createdAtMsg1.toISOString(), user: client.user }] };
+		channel._initializeState(newState);
+		expect(channel.state.read[client.user.id].first_unread_message_id).to.be.equal(messages[1].id);
+		newState = { messages, read: [{ last_read: createdAtMsg1.toISOString(), user: client.user }] };
+		channel._initializeState(newState);
+		expect(channel.state.read[client.user.id].first_unread_message_id).to.be.equal(messages[1].id);
+	});
 });