add error event test

test/application/events.js

@@ -43,4 +43,31 @@ describe('app emits events', () => {
  assert.deepStrictEqual(emitted, ['request', 'fistMiddleWare', 'customEvent', 'lastMiddleware', 'respond', 'responded']);
  assert.strictEqual(onceEvents, 3);
  });
+
+ it('should emit error event on middleware throw', async() => {
+ const app = new Koa();
+ const emitted = [];
+ app.on('error', err => emitted.push(err));
+
+ app.use((ctx, next) => {
+ throw new TypeError('Hello Koa!');
+ });
+
+ const server = app.listen();
+
+ let onceEvents = 0;
+ app.once('error', (err, ctx) => {
+ assert.ok(err instanceof TypeError);
+ assert.strictEqual(ctx.app, app);
+ onceEvents++;
+ });
+
+ await request(server)
+ .get('/')
+ .expect(500);
+
+ assert.deepStrictEqual(emitted.length, 1);
+ assert.ok(emitted[0] instanceof TypeError);
+ assert.strictEqual(onceEvents, 1);
+ });
 });