vscode: added engine test

extension/test/engine.test.ts

@@ -0,0 +1,47 @@
+import * as assert from 'assert';
+import { WorkerHandle, WorkerDisposedError } from '../src/engine';
+import { Rpc } from '../src/rpc';
+
+/** A handle whose rpc never gets a reply, so calls stay pending. */
+function pendingHandle(log: (msg: string) => void) {
+  var handle = new WorkerHandle('fake.js', '', {}, log);
+  var port: any = { on() { }, postMessage() { }, terminate() { } };
+  (handle as any).rpc = new Rpc(port);
+  return handle;
+}
+
+describe('WorkerHandle.notify', function () {
+  it('ignores a call pending when the worker is disposed', async function () {
+    var logged: string[] = [];
+    var handle = pendingHandle(m => logged.push(m));
+    var unhandled: any[] = [];
+    var onUnhandled = (e: any) => unhandled.push(e);
+    process.on('unhandledRejection', onUnhandled);
+    try {
+      handle.notify('setMuted', true);
+      handle.dispose();
+      await new Promise(r => setImmediate(r));
+    } finally {
+      process.off('unhandledRejection', onUnhandled);
+    }
+    assert.deepEqual(unhandled, []);
+    assert.deepEqual(logged, []);
+  });
+
+  it('logs other failures', async function () {
+    var logged: string[] = [];
+    var handle = pendingHandle(m => logged.push(m));
+    handle.notify('setMuted', true);
+    (handle as any).rpc.rejectAll(new Error('boom'));
+    await new Promise(r => setImmediate(r));
+    assert.equal(logged.length, 1);
+    assert.ok(logged[0].includes('boom'), logged[0]);
+  });
+
+  it('call() still rejects with WorkerDisposedError on dispose', async function () {
+    var handle = pendingHandle(() => { });
+    var p = handle.call('x');
+    handle.dispose();
+    await assert.rejects(p, WorkerDisposedError);
+  });
+});