Friends, I have a problem!

I'm testing my API with NestJS. I'm using Jest for the test. Unfortunately, I am encountering the following error:

TypeError: Cannot read properties of undefined (reading 'close')

This error is very explicit but I don't see where it could come from.

Would you have an idea?

My current code :

import * as pactum from 'pactum';
import { Test } from '@nestjs/testing';
import { AppModule } from '../src/app.module';
import { INestApplication, ValidationPipe } from '@nestjs/common';
import { PrismaService } from '../src/prisma/prisma.service';
import { AuthDto } from '../src/auth/dto';

describe('App e2e', () => {
  let app: INestApplication;
  let prisma: PrismaService;

  beforeAll(async () => {
    const moduleRef = await Test.createTestingModule({
      imports: [AppModule],
    }).compile();

    const app = moduleRef.createNestApplication();
    app.useGlobalPipes(
      new ValidationPipe({
        whitelist: true,
      }),
    );
    await app.init();
    await app.listen(3334);

    prisma = app.get(PrismaService);
    await prisma.cleanDatabase();
  });

  afterAll(async () => {
    console.log('Closing server');
    await app.close(); // <------------- THE PROBLEM ARISES HERE.
  });

  describe('Auth', () => {
    describe('Signup', () => {
      it('should signup a user', () => {
        const dto: AuthDto = {
          email: '[email protected]',
          password: '1234',
        };
        return pactum
          .spec()
          .post('http://localhost:3333/auth/signup')
          .withBody(dto)
          .expectStatus(201);
      });
    });
    describe('Signin', () => {
      it.todo('should signin a user');
    });
  });
});

CodePudding user response：

You are mixing two variables in different scopes.

let app: INestApplication; is upper scope one which you are actually using, since it does not have any value assigned it is undefined. The inner one is different because you are defining inside another scope.

A solution is very simple, just remove const from const app = moduleRef.createNestApplication();