diff --git a/apps/meteor/server/lib/messages/sendMessage.spec.ts b/apps/meteor/server/lib/messages/sendMessage.spec.ts
new file mode 100644
index 0000000000000..1f0e15469e3b1
--- /dev/null
+++ b/apps/meteor/server/lib/messages/sendMessage.spec.ts
@@ -0,0 +1,49 @@
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+
+import { prepareMessageObject } from './sendMessage';
+
+describe('sendMessage', () => {
+	describe('prepareMessageObject', () => {
+		it('should set ts if not provided', () => {
+			const message: any = {};
+			prepareMessageObject(message, 'rid123', { _id: 'u123', username: 'testuser', name: 'Test User' });
+			expect(message.ts).to.be.a('date');
+		});
+
+		it('should preserve existing ts', () => {
+			const date = new Date('2023-01-01T00:00:00.000Z');
+			const message: any = { ts: date };
+			prepareMessageObject(message, 'rid123', { _id: 'u123', username: 'testuser', name: 'Test User' });
+			expect(message.ts).to.equal(date);
+		});
+
+		it('should set rid correctly', () => {
+			const message: any = {};
+			prepareMessageObject(message, 'rid123', { _id: 'u123', username: 'testuser', name: 'Test User' });
+			expect(message.rid).to.equal('rid123');
+		});
+
+		it('should set user details correctly', () => {
+			const message: any = {};
+			prepareMessageObject(message, 'rid123', { _id: 'u123', username: 'testuser', name: 'Test User' });
+			expect(message.u).to.be.an('object');
+			expect(message.u._id).to.equal('u123');
+			expect(message.u.username).to.equal('testuser');
+			expect(message.u.name).to.equal('Test User');
+		});
+
+		it('should throw an error if username is not provided', () => {
+			const message: any = {};
+			expect(() => {
+				prepareMessageObject(message, 'rid123', { _id: 'u123', name: 'Test User' });
+			}).to.throw('error-invalid-user');
+		});
+
+		it('should delete tshow if it is not exactly true', () => {
+			const message: any = { tshow: false };
+			prepareMessageObject(message, 'rid123', { _id: 'u123', username: 'testuser', name: 'Test User' });
+			expect(message).to.not.have.property('tshow');
+		});
+	});
+});