feat: reject emitted promise on error in EventEmitter

Author: bigint

src/lib/EventEmitter.ts

@@ -74,7 +74,7 @@ export class EventEmitter<EventTypes extends Record<string, (...args: any) => an
     : EventParameters<EventTypes, Event>
   > {
     return new Promise((resolve, reject) => {
-      // TODO: handle errors
+      if (event !== 'error') this.once('error', reject as any);
       this.once(event, resolve as any);
     });
   }

tests/lib/eventEmitter.test.ts

@@ -0,0 +1,33 @@
+import { EventEmitter } from 'openai/lib/EventEmitter';
+
+interface TestEvents {
+  foo: (value: string) => void;
+  error: (err: Error) => void;
+}
+
+class TestEmitter extends EventEmitter<TestEvents> {
+  emitFoo(value: string) {
+    this._emit('foo', value);
+  }
+  emitError(err: Error) {
+    this._emit('error', err);
+  }
+}
+
+describe('EventEmitter.emitted', () => {
+  test('resolves when event is emitted', async () => {
+    const emitter = new TestEmitter();
+    const promise = emitter.emitted('foo');
+    emitter.emitFoo('bar');
+    await expect(promise).resolves.toBe('bar');
+  });
+
+  test('rejects if error emitted before event', async () => {
+    const emitter = new TestEmitter();
+    const promise = emitter.emitted('foo');
+    const error = new Error('oops');
+    emitter.emitError(error);
+    emitter.emitFoo('bar');
+    await expect(promise).rejects.toBe(error);
+  });
+});