refactor(test): extract stack creation to external factory, recreate …

…one for each test for better isolation

test/factory.ts

@@ -0,0 +1,48 @@
+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';
+
+export async function factory() {
+  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
+      })
+    ]
+  });
+
+  await once(broker, 'listening');
+  await once(mqttClient, 'connect');
+
+  return {
+    client,
+    broker,
+    mqttClient,
+    close() {
+      mqttClient.end();
+      broker.close();
+      aedes.close();
+    }
+  };
+}

test/index.test.ts

@@ -1,74 +1,52 @@
-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
-    })
-  ]
-});
+import { factory } from './factory';
 
-beforeAll(async () => {
-  await once(broker, 'listening');
-  await once(mqttClient, 'connect');
-});
+test('broker is listening', async () => {
+  const { broker, close } = await factory();
 
-test('broker is listening', () => {
   expect(broker.listening).toBe(true);
+
+  close();
 });
 
-test('mqtt client is connected', () => {
+test('mqtt client is connected', async () => {
+  const { mqttClient, close } = await factory();
+
   expect(mqttClient.connected).toBe(true);
+
+  close();
 });
 
 test('greet query', async () => {
+  const { client, close } = await factory();
+
   const greeting = await client.greet.query('world');
   expect(greeting).toEqual({ greeting: 'hello, world!' });
+
+  close();
 });
 
 test('countUp mutation', async () => {
+  const { client, close } = await factory();
+
   const addOne = await client.countUp.mutate(1);
   expect(addOne).toBe(1);
 
   const addTwo = await client.countUp.mutate(2);
   expect(addTwo).toBe(3);
+
+  close();
 });
 
 test('abortSignal is handled', async () => {
+  const { client, close } = await factory();
+
   const controller = new AbortController();
   const promise = client.slow.query(undefined, {
     signal: controller.signal
   });
 
   controller.abort();
   await expect(promise).rejects.toThrow('aborted');
-});
 
-afterAll(async () => {
-  mqttClient.end();
-  broker.close();
-  aedes.close();
+  close();
 });