fix: support multiple file exports in room message export

.changeset/quick-schools-hear.md

@@ -0,0 +1,5 @@
+---
+'@rocket.chat/meteor': patch
+---
+
+Fixes room message export to correctly handle messages with multiple files.

apps/meteor/server/lib/dataExport/exportRoomMessagesToFile.ts

@@ -163,7 +163,7 @@ export const getMessageData = (
 	return messageObject;
 };
 
-export const exportMessageObject = (type: 'json' | 'html', messageObject: MessageData, messageFile?: FileProp): string => {
+export const exportMessageObject = (type: 'json' | 'html', messageObject: MessageData, messageFiles: FileProp[] = []): string => {
 	if (type === 'json') {
 		return JSON.stringify(messageObject);
 	}
@@ -180,14 +180,16 @@ export const exportMessageObject = (type: 'json' | 'html', messageObject: Messag
 	file.push(`<p><strong>${messageObject.username}</strong> (${timestamp}):<br/>`);
 	file.push(message);
 
-	if (messageFile?._id) {
-		const attachment = messageObject.attachments?.find((att) => att.type === 'file' && att.title_link?.includes(messageFile._id));
+	for (const messageFile of messageFiles) {
+		if (messageFile?._id) {
+			const attachment = messageObject.attachments?.find((att) => att.type === 'file' && att.title_link?.includes(messageFile._id));
 
-		const description = attachment?.title || i18n.t('Message_Attachments');
+			const description = attachment?.title || i18n.t('Message_Attachments');
 
-		const assetUrl = `./assets/${messageFile._id}-${messageFile.name}`;
-		const link = `<br/><a href="${assetUrl}">${description}</a>`;
-		file.push(link);
+			const assetUrl = `./assets/${messageFile._id}-${messageFile.name}`;
+			const link = `<br/><a href="${assetUrl}">${description}</a>`;
+			file.push(link);
+		}
 	}
 
 	file.push('</p>');
@@ -229,11 +231,12 @@ export const exportRoomMessages = async (
 	results.forEach((msg) => {
 		const messageObject = getMessageData(msg, hideUsers, userData, usersMap);
 
-		if (msg.file) {
-			result.uploads.push(msg.file);
-		}
+		// handle both new format (msg.files array) and old format (msg.file) for backward compatibility
+		// and filter out thumbnails (typeGroup === 'thumb') to only include actual files
+		const files = (msg.files || (msg.file ? [msg.file] : [])).filter((file) => file && file.typeGroup !== 'thumb');
 
-		result.messages.push(exportMessageObject(exportType, messageObject, msg.file));
+		result.uploads.push(...files);
+		result.messages.push(exportMessageObject(exportType, messageObject, files));
 	});
 
 	return result;

apps/meteor/tests/unit/server/lib/dataExport/exportRoomMessagesToFile.spec.ts

@@ -87,7 +87,7 @@ describe('Export - exportMessageObject', () => {
 	});
 
 	it('should correctly reference file when exporting a message object with an attachment as html', async () => {
-		const result = await exportMessageObject('html', messagesData[1], exportMessagesMock[1].file);
+		const result = await exportMessageObject('html', messagesData[1], [exportMessagesMock[1].file]);
 
 		expect(result).to.be.a.string;
 		expect(result).to.equal(
@@ -100,7 +100,7 @@ describe('Export - exportMessageObject', () => {
 	});
 
 	it('should use fallback attachment description when no title is provided on message object export as html', async () => {
-		const result = await exportMessageObject('html', messagesData[2], exportMessagesMock[2].file);
+		const result = await exportMessageObject('html', messagesData[2], [exportMessagesMock[2].file]);
 
 		expect(stubs.translateKey.calledWith('Message_Attachments')).to.be.true;
 		expect(result).to.be.a.string;
@@ -155,4 +155,56 @@ describe('Export - exportRoomMessages', () => {
 		const messagesWithFiles = exportMessagesMock.filter((message) => message.file);
 		expect(result).to.have.property('uploads').that.is.an('array').of.length(messagesWithFiles.length);
 	});
+
+	it('should export multiple files and filter out thumbnails', async () => {
+		const message = {
+			_id: faker.database.mongodbObjectId(),
+			rid: 'test-rid',
+			ts: new Date(),
+			u: { _id: faker.database.mongodbObjectId(), username: 'testuser' },
+			msg: 'Message with files',
+			files: [
+				{ _id: 'file-1', name: 'photo.jpg', type: 'image/jpeg', size: 500000 },
+				{ _id: 'file-2', name: 'doc.pdf', type: 'application/pdf', size: 10000 },
+				{ _id: 'thumb-1', name: 'photo_thumb.jpg', type: 'image/jpeg', size: 5000, typeGroup: 'thumb' },
+			],
+			attachments: [{ type: 'file', title: 'photo.jpg', title_link: '/file-upload/file-1/photo.jpg' }],
+		};
+
+		stubs.findPaginatedMessagesCursor.resolves([message]);
+		stubs.findPaginatedMessagesTotal.resolves(1);
+		stubs.findPaginatedMessages.returns({
+			cursor: { toArray: stubs.findPaginatedMessagesCursor },
+			totalCount: stubs.findPaginatedMessagesTotal(),
+		});
+
+		const result = await exportRoomMessages('test-rid', 'html', 0, 100, userData);
+
+		expect(result.uploads).to.have.length(2);
+		expect(result.uploads.some((f: { typeGroup?: string }) => f.typeGroup === 'thumb')).to.be.false;
+	});
+
+	it('should fallback to msg.file when msg.files is not available', async () => {
+		const message = {
+			_id: faker.database.mongodbObjectId(),
+			rid: 'test-rid',
+			ts: new Date(),
+			u: { _id: faker.database.mongodbObjectId(), username: 'testuser' },
+			msg: 'Old format message',
+			file: { _id: 'single-file', name: 'doc.pdf', type: 'application/pdf', size: 10000 },
+			attachments: [{ type: 'file', title: 'doc.pdf', title_link: '/file-upload/single-file/doc.pdf' }],
+		};
+
+		stubs.findPaginatedMessagesCursor.resolves([message]);
+		stubs.findPaginatedMessagesTotal.resolves(1);
+		stubs.findPaginatedMessages.returns({
+			cursor: { toArray: stubs.findPaginatedMessagesCursor },
+			totalCount: stubs.findPaginatedMessagesTotal(),
+		});
+
+		const result = await exportRoomMessages('test-rid', 'html', 0, 100, userData);
+
+		expect(result.uploads).to.have.length(1);
+		expect(result.uploads[0]._id).to.equal('single-file');
+	});
 });