diff --git a/test/appRouter.ts b/test/appRouter.ts
index f3a3bb2..cb8c42d 100644
--- a/test/appRouter.ts
+++ b/test/appRouter.ts
@@ -7,11 +7,22 @@ const t = initTRPC.create();
 const publicProcedure = t.procedure;
 const router = t.router;
 
+const state = { count: 0 };
+
 export const appRouter = router({
   greet: publicProcedure
     .input((val: unknown) => {
       if (typeof val === 'string') return val;
       throw new Error(`Invalid input: ${typeof val}`);
     })
-    .query(({ input }) => ({ greeting: `hello, ${input}!` }))
+    .query(({ input }) => ({ greeting: `hello, ${input}!` })),
+  countUp: publicProcedure
+    .input((val: unknown) => {
+      if (typeof val === 'number') return val;
+      throw new Error(`Invalid input: ${typeof val}`);
+    })
+    .mutation(({ input }) => {
+      state.count += input;
+      return state.count;
+    })
 });
diff --git a/test/broker.ts b/test/broker.ts
new file mode 100644
index 0000000..3d39041
--- /dev/null
+++ b/test/broker.ts
@@ -0,0 +1,9 @@
+import Aedes from 'aedes';
+import { createServer } from 'net';
+
+const aedes = new Aedes();
+const server = createServer(aedes.handle);
+
+server.listen(1883, () => {
+  console.log('server started and listening on port 1883');
+});
diff --git a/test/client.ts b/test/client.ts
deleted file mode 100644
index 04aa429..0000000
--- a/test/client.ts
+++ /dev/null
@@ -1,26 +0,0 @@
-import { createTRPCProxyClient } from '@trpc/client';
-import mqtt from 'mqtt';
-
-import { mqttLink } from '../src/link';
-import type { AppRouter } from './appRouter';
-
-const client = mqtt.connect('mqtt://localhost');
-
-export const trpc = createTRPCProxyClient<AppRouter>({
-  links: [
-    mqttLink({
-      client,
-      requestTopic: 'rpc/request'
-    })
-  ]
-});
-
-const main = async () => {
-  const greeting = await trpc.greet.query('world');
-  console.log(greeting);
-  console.log('Closing MQTT client...');
-  client.end();
-  console.log('MQTT client closed.');
-};
-
-main();
diff --git a/test/index.test.ts b/test/index.test.ts
new file mode 100644
index 0000000..a05586e
--- /dev/null
+++ b/test/index.test.ts
@@ -0,0 +1,64 @@
+import { createTRPCProxyClient } from '@trpc/client';
+import Aedes from 'aedes';
+import { once } from 'events';
+import mqtt from 'mqtt';
+import { createServer } from 'net';
+
+import { createMQTTHandler } from '../src/adapter';
+import { mqttLink } from '../src/link';
+import { AppRouter, appRouter } from './appRouter';
+
+const requestTopic = 'rpc/request';
+
+const aedes = new Aedes();
+// aedes.on('publish', (packet, client) => console.log(packet.topic, packet.payload.toString()));
+const broker = createServer(aedes.handle);
+broker.listen(1883);
+const mqttClient = mqtt.connect('mqtt://localhost');
+
+createMQTTHandler({
+  client: mqttClient,
+  requestTopic,
+  router: appRouter
+});
+
+const client = createTRPCProxyClient<AppRouter>({
+  links: [
+    mqttLink({
+      client: mqttClient,
+      requestTopic
+    })
+  ]
+});
+
+beforeAll(async () => {
+  await once(broker, 'listening');
+  await once(mqttClient, 'connect');
+});
+
+test('broker is listening', () => {
+  expect(broker.listening).toBe(true);
+});
+
+test('mqtt client is connected', () => {
+  expect(mqttClient.connected).toBe(true);
+});
+
+test('greet query', async () => {
+  const greeting = await client.greet.query('world');
+  expect(greeting).toEqual({ greeting: 'hello, world!' });
+});
+
+test('countUp mutation', async () => {
+  const addOne = await client.countUp.mutate(1);
+  expect(addOne).toBe(1);
+
+  const addTwo = await client.countUp.mutate(2);
+  expect(addTwo).toBe(3);
+});
+
+afterAll(async () => {
+  mqttClient.end();
+  broker.close();
+  aedes.close();
+});
diff --git a/test/server.ts b/test/server.ts
deleted file mode 100644
index 5a827d5..0000000
--- a/test/server.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import mqtt from 'mqtt';
-
-import { createMQTTHandler } from '../src/adapter';
-import { appRouter } from './appRouter';
-
-const client = mqtt.connect('mqtt://localhost');
-
-createMQTTHandler({
-  client,
-  requestTopic: 'rpc/request',
-  router: appRouter
-});
-
-process.on('SIGINT', () => {
-  console.log('Closing MQTT client...');
-  client.end();
-  console.log('MQTT client closed.');
-});