feat(test): add abortSignal test

test/appRouter.ts

@@ -24,5 +24,9 @@ export const appRouter = router({
     .mutation(({ input }) => {
       state.count += input;
       return state.count;
-    })
+    }),
+  takesASecondToResolve: publicProcedure.query(async () => {
+    await new Promise(resolve => setTimeout(resolve, 2000));
+    return 'done';
+  })
 });

test/index.test.ts

@@ -57,6 +57,19 @@ test('countUp mutation', async () => {
   expect(addTwo).toBe(3);
 });
 
+test('abortSignal is handled & event listeners cleaned up', async () => {
+  const controller = new AbortController();
+  const promise = client.takesASecondToResolve.query(undefined, {
+    signal: controller.signal
+  });
+
+  controller.abort();
+  await expect(promise).rejects.toThrow('aborted');
+
+  // Only the server should still be listening, client should have cleaned up
+  expect(mqttClient.listeners('message').length).toBe(1);
+});
+
 afterAll(async () => {
   mqttClient.end();
   broker.close();