Nestjs e2e test fails with getHttpServer but works with .agent - jestjs

Question

I was trying to write my first e2e test in nestjs using the following code:
describe('AppController (e2e)', () => {
let app: INestApplication;
beforeAll(async () => {
const moduleFixture: TestingModule = await Test.createTestingModule({
imports: [
AppModule,
]
}).compile();
app = moduleFixture.createNestApplication();
await app.init();
await getConnection().synchronize(true);
});
it('/ (GET)', async () => {
return request(app.getHttpServer())
.get('/')
.expect(200);
});
afterAll(async () => {
await app.close();
});
});
It always fails with 404, when trying to debug the supertest request I saw:
{
errno: -61,
code: 'ECONNREFUSED',
syscall: 'connect',
address: '127.0.0.1',
port: 57523,
response: undefined
}
If I try to connect to the actual app using .agent('127.0.0.1:3000') the test passes.
it('/ (GET)', async () => {
return request
.agent('127.0.0.1:3000')
.get('/')
.expect(200)
});

Answer 1

You have to await the response. Do something like. Look at below snippet where i have added await to response instead of return
it('should throw validation error when creating employer policy', async () => {
const data = {
max_percent_of_salary: true,
is_employer_paid: true,
has_advance_activated: false,
};
const response = await request(app.getHttpServer())
.post('/sa-employer-policy/create/')
.set('Accept', 'application/json')
.set('Authorization', 'Bearer ' + employer_token)
.send(data)
.expect(HttpStatus.BAD_REQUEST);
expect(response.body.message).toBeDefined();
});

Answer 2

The problem was that I was using an endpoint from a controller without importing the parent module.