nodejs async await 在测试中不等待

Question

I've a nodejs jest test and it fails because it does not wait Promise .

it('returns an error if the ticket is already reserved', async () => {
    const ticket = Ticket.build({
        title: 'Concert',
        price: 20
    });
    await ticket.save();

    console.log('TICKET ID:', ticket.id);

    const order = Order.build({
        userId: 'asdasd',
        status: OrderStatus.Created,
        expiresAt: new Date(),
        ticket
    });

    await order.save();

    console.log('Order ID:', order.id);
    
    await request(app)
        .post('api/orders')
        .set('Cookie', global.signin())
        .send({
            ticketId: ticket.id
        })
        .expect(400);

});

In the controller I've function like below.

import mongoose from 'mongoose';
import { Ticket } from '../models/ticket';

router.post('/api/orders',
    ...,
    async (req: Request, res: Response) => {

        const { ticketId } = req.body;
        //Find the ticket the user is trying to order in the database
        const ticket = await Ticket.findById(ticketId);
        console.log('TICKET IN REQUEST: ', ticket);
        
        if (!ticket) {
            throw new NotFoundError();
        }

       ....

        res.status(201).send(order);
    });

export { router as newOrderRouter };

Let me explain in a simple way. In test, I try to create a ticket in mongoDB and request my API to see ticket is created or not.

You can see in console.log() outputs below.

console.log
    TICKET IN REQUEST:  null

      at src/routes/new.ts:27:17

  console.log
    TICKET ID: 5f6c3c7fd8bc648884890dc3

      at src/routes/__tests__/new.test.ts:27:13

  console.log
    Order ID: 5f6c3c7fd8bc648884890dc4

      at src/routes/__tests__/new.test.ts:38:13

So as you can see the order of logs are not in desired. API is called without waiting the other mongoDB save operations finish. Mongoose save operation returns promise. So it should wait. But I couldn't understand the problem. Any idea?

Answer 1

@ahmet, this is because you are comparing results before promise is resolved. you should use expect in promise.then or store await result in a variable then compare it (test case)

it('returns an error if the ticket is already reserved', async () => {
    const ticket = Ticket.build({
        title: 'Concert',
        price: 20
    });
    await ticket.save();

    console.log('TICKET ID:', ticket.id);

    const order = Order.build({
        userId: 'asdasd',
        status: OrderStatus.Created,
        expiresAt: new Date(),
        ticket
    });

    await order.save();

    console.log('Order ID:', order.id);
    
    const result=await request(app)
        .post('api/orders')
        .set('Cookie', global.signin())
        .send({
            ticketId: ticket.id
        });
    result.expect(400);

    //or this one
    //request(app)
   //   .post('api/orders')
   //   .set('Cookie', global.signin())
   //   .send({
   //       ticketId: ticket.id
   //   }).then(result=>result.expect(400))
});