Cannot read property 'find' of inherited method in unit tests - mongodb

Question

im having an issue trying to run an e2e test for my NestJS application tha uses a mongodb-memory-server to run mongo in memory
my e2e test looks like this
describe('UsersController.e2e', () => {
let app: INestApplication;
let module: TestingModule;
const mongod = new MongoMemoryServer();
beforeAll(async () => {
const port = await mongod.getPort();
const database = await mongod.getDbName();
module = await Test.createTestingModule({
providers: [UserRepository, UserService],
controllers: [UserController],
imports: [TypeOrmModule.forRootAsync({
useFactory: () => {
return {
type: 'mongodb',
host: '127.0.0.1',
port,
database,
entities: [__dirname + '../../../**/*.entity{.ts,.js}'],
} as TypeOrmModuleOptions;
},
}),
TypeOrmModule.forFeature([User])
]
}).compile();
app = module.createNestApplication();
await app.init();
});
afterAll(async () => {
await module.close();
await app.close();
});
describe('GET /users', () => {
it('should return a collection of user resources', async () => {
const { body } = await supertest
.agent(app.getHttpServer())
.get('/users')
.set('Accept', 'application/json')
.expect('Content-Type', /json/)
.expect(200);
expect(body).toEqual(userCollectionMock);
});
});
});
when running the test it throws a 500 error
Cannot read property 'find' of undefined
TypeError: Cannot read property 'find' of undefined
at UserRepository.Object.<anonymous>.MongoRepository.find (src/repository/MongoRepository.ts:77:29)
at UserRepository.index (src/modules/user/repositories/user.repository.ts:12:20)
the repository class looks like
export class UserRepository extends MongoRepository<User> implements IResourceRepository<User> {
index(): Promise<User[]> {
return this.find();
}
}
the extension of MongoRepository provides find() https://github.com/typeorm/typeorm/blob/master/src/repository/MongoRepository.ts#L76
So it perplexes me as to why it is undefined!

Answer 1

I know this is a month old, but I just ran into this issue and resolved it.
I'm using mongoose + typegoose with mongodb-memory-server.
import { MongoMemoryServer } from 'mongodb-memory-server';
describe('Auth', () => {
let app: INestApplication;
let mongoServer: MongoMemoryServer;
beforeAll(async () => {
// Set up database
mongoServer = new MongoMemoryServer();
const mongoUri = await mongoServer.getUri();
const moduleRef = await Test.createTestingModule({
imports: [
...
TypegooseModule.forRoot(mongoUri, {
useNewUrlParser: true,
useUnifiedTopology: true,
}),
...
],
controllers: [...],
providers: [...],
}).compile();
app = moduleRef.createNestApplication();
await app.init();
});
afterAll(async () => {
await mongoServer.stop();
});
});
The main mistake I was making was that I had separately overwritten my User Typegoose injection.
providers: [
// THIS WAS MY MISTAKE!
{
provide: getModelToken('User'),
useValue: mockUserModel,
},
],
I know this is not a complete answer to your question, but I hope this might help you.