feat: update messageSet pagination on merge

src/channel_state.ts

@@ -854,6 +854,14 @@ export class ChannelState<StreamChatGenerics extends ExtendableGenerics = Defaul
         sources.forEach((messageSet) => {
           target.isLatest = target.isLatest || messageSet.isLatest;
           target.isCurrent = target.isCurrent || messageSet.isCurrent;
+          target.pagination.hasPrev =
+            messageSet.messages[0].created_at < target.messages[0].created_at
+              ? messageSet.pagination.hasPrev
+              : target.pagination.hasPrev;
+          target.pagination.hasNext =
+            target.messages.slice(-1)[0].created_at < messageSet.messages.slice(-1)[0].created_at
+              ? messageSet.pagination.hasNext
+              : target.pagination.hasNext;
           messagesToAdd = [...messagesToAdd, ...messageSet.messages];
         });
         sources.forEach((s) => this.messageSets.splice(this.messageSets.indexOf(s), 1));

test/unit/channel_state.js

@@ -533,7 +533,9 @@ describe('ChannelState addMessagesSorted', function () {
 			const currentMessages = [generateMsg({ id: '10', date: '2020-01-01T00:00:03.001Z' }), ...overlap1];
 			state.addMessagesSorted(currentMessages, false, true, true, 'new');
 			state.messageSets[0].isCurrent = false;
+			state.messageSets[0].pagination = {hasPrev: true, hasNext: false};
 			state.messageSets[1].isCurrent = true;
+			state.messageSets[1].pagination = {hasPrev: false, hasNext: true};
 			const newMessages = [...overlap1, generateMsg({ id: '12', date: '2020-01-01T00:00:14.001Z' }), ...overlap2];
 			state.addMessagesSorted(newMessages, false, true, true, 'new');
 
@@ -545,6 +547,7 @@ describe('ChannelState addMessagesSorted', function () {
 			expect(state.messages[4].id).to.be.equal('14');
 			expect(state.messages).to.be.equal(state.latestMessages);
 			expect(state.messageSets.length).to.be.equal(1);
+			expect(state.messageSets[0].pagination).to.be.eql({hasPrev: false, hasNext: false});
 		});
 	});
 });