diff --git a/src/__tests__/TuitioClient.test.ts b/src/__tests__/TuitioClient.test.ts
index d736877..de6fd88 100644
--- a/src/__tests__/TuitioClient.test.ts
+++ b/src/__tests__/TuitioClient.test.ts
@@ -1,6 +1,7 @@
 import { getUrlTemplates } from "../config";
 import { combineUrls } from "../utils";
 import { TuitioClient } from "../client";
+import type { TuitioAuthenticationResult, TuitioToken } from "../client";
 
 test("Combine urls with trailing slash", () => {
   const result = combineUrls("https://test.com/api/", "/test");
@@ -21,6 +22,24 @@ test("Get url templates", () => {
 });
 
 test("Tuitio client initialization", () => {
-  const result = new TuitioClient("https://test.com/api");
-  expect(result.baseUrl).toBe("https://test.com/api");
+  const client = new TuitioClient("https://test.com/api");
+  expect(client.baseUrl).toBe("https://test.com/api");
+});
+
+test("Tuitio client authentication", async () => {
+  const client = new TuitioClient("https://test.com/api");
+  const spy = jest.spyOn(client, "authenticate").mockImplementation(async (userName, password) => {
+    const token = <TuitioToken>{ raw: `mock-${userName}-${password}`, validFrom: new Date("10/02/2023"), validUntil: new Date("11/02/2023") };
+    const authResult = <TuitioAuthenticationResult>{ token, status: "_MOCK_" };
+    return authResult;
+  });
+
+  const result = await client.authenticate("user", "pass");
+
+  expect(result.token.raw).toBe("mock-user-pass");
+  expect(result.token.validFrom).toStrictEqual(new Date("10/02/2023"));
+  expect(result.token.validUntil).toStrictEqual(new Date("11/02/2023"));
+  expect(result.status).toBe("_MOCK_");
+
+  spy.mockRestore();
 });