e2e test failing - getRepository is null

Question

When I run the e2e test(as integration tests) I get a getRepository null error. I import the entire app module in my test spec file(below),the error occurs, which says something like this:

[Nest] 47867  - 08/22/2022, 8:07:35 PM   ERROR [ExceptionsHandler] Cannot read property 'getRepository' of null
TypeError: Cannot read property 'getRepository' of null
TypeError: Cannot read property 'getRepository' of null
    at new usersService (/mypath/src/users/users.service.ts:35:42)
    at Injector.instantiateClass (/mypath/node_modules/@nestjs/core/injector/injector.js:330:19)
    at callback (/mypath/node_modules/@nestjs/core/injector/injector.js:48:41)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at Injector.loadInstance (/mypath/node_modules/@nestjs/core/injector/injector.js:52:9)
    at Injector.loadProvider (/mypath/node_modules/@nestjs/core/injector/injector.js:74:9)
    at Injector.resolveComponentHost (/mypath/node_modules/@nestjs/core/injector/injector.js:192:13)
    at async Promise.all (index 0)
    at Injector.loadCtorMetadata (/mypath/node_modules/@nestjs/core/injector/injector.js:358:23)
    at Injector.resolveConstructorParams (/mypath/node_modules/@nestjs/core/injector/injector.js:89:26)
 FAIL  test/user.service.int-spec.ts (10.525 s)
  GET /users 
    ✓ (GET) / (102 ms)
    ✕ (GET) /users (62 ms)

  ● GET /users  › (GET) /users

    expected 200 "OK", got 500 "Internal Server Error"

      26 |
      27 |   it('(GET) /users', () => {
    > 28 |     return request(app.getHttpServer()).get('/users').expect(200);
         |                                                           ^
      29 |   });
      30 | });
      31 |

      at Object.<anonymous> (test/user.service.int-spec.ts:28:59)
      ----
      at Test._assertStatus (node_modules/supertest/lib/test.js:252:14)
      at node_modules/supertest/lib/test.js:306:17
      at Test._assertFunction (node_modules/supertest/lib/test.js:285:13)
      at Test.assert (node_modules/supertest/lib/test.js:164:23)
      at Server.localAssert (node_modules/supertest/lib/test.js:120:14)

The folder structure is this:

parent_folder
| package.json
| package-lock.json
| ---src
|    \-User
|       \-user.module.ts
|       \-user.service.ts
|       \-user.controller.ts
|...
| ---tests
|    \-jest-int.json
|    \-user.int-spec.ts  


The jest config file contains this:
{
  "moduleFileExtensions": ["js", "json", "ts"],
  "rootDir": "../",  // <<<--- I use absolute path path, so rootDir is "../"
  "roots": ["<rootDir>"],
  "modulePaths": ["<rootDir>"],
  "moduleDirectories": ["node_modules"],
  "testEnvironment": "node",
  "testRegex": ".int-spec.ts$",
  "transform": {
    "^.+\\.(t|j)s$": "ts-jest"
  }
}  

The module contains this only:

import { Module } from '@nestjs/common';
import { UsersController } from './Users.controller';
import { UsersService } from './Users.service';

@Module({
  providers: [UsersService],
  controllers: [UsersController],
})
export class UserModule {}

The service contains:

@Injectable()
export class UsersService {
  private userRepository: Repository<User>;
  private fileRepository: Repository<file>;
  private filedworthRepository: Repository<filedworth>;
  private filedValueRepository: Repository<filedValue>;
  private fileStrategyRepository: Repository<fileStrategy>;
  private valueRepository: Repository<Value>;
  private defaultData = {
    created_date: new Date(),
    updated_date: new Date(),
    created_by: 'user',
    updated_by: 'user',
  };

  constructor(@Inject(CONNECTION) private connection: DataSource) {
    this.userRepository = connection.getRepository(user);
    this.fileRepository = connection.getRepository(file);
    this.filedworthRepository =
      connection.getRepository(filedworth);
    this.filedValueRepository =
      connection.getRepository(filedValue);
    this.fileStrategyRepository =
      connection.getRepository(fileStrategy);
    this.ValueRepository = connection.getRepository(Value);
  }
  ...//other methods
}     
  

The controller is:

@Controller('users')
export class usersController {
  constructor(private usersService: usersService) {}

  @Get()
  getusers(
    @Query()
    query: GetUsersFilterDto,
  ) {
    return this.usersService.getusers(query);
  }
  ...//others
}  

and the test file itself contains the following:

import { Test, TestingModule } from '@nestjs/testing';
import { INestApplication } from '@nestjs/common';
import * as request from 'supertest';
import { AppModule } from './../src/app.module';

describe('GET /users ', () => {
  let app: INestApplication;

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

    app = moduleFixture.createNestApplication();

    await app.init();
  });

  afterAll(async () => {
    await app.close();
  });

  it('(GET) /', () => {
    return request(app.getHttpServer()).get('/').expect(200);
  });

  it('(GET) /users', () => {
    return request(app.getHttpServer()).get('/users').expect(200);
  });
});  

I run the test using:

npm run test:int // "test:int": "jest -i --no-cache  --detectOpenHandles --config ./test/jest-int.json"

Is there something I'm missing? Hopefully these are enough details to convey my issue.

Answer 1

What Georgi has mentioned was true, I hadn't provided the values of the dependency CONNECTION that was being injected. But, the syntax mentioned there didn't work, this did:

beforeAll(async () => {
    const connection = await DataSource(myDB_Config);//hosturl, port etc.
    const moduleFixture: TestingModule = await Test.createTestingModule({
      imports: [AppModule],
    })
      .overrideProvider(CONNECTION)
      .useValue(connection)
      .compile();

    app = moduleFixture.createNestApplication();

    await app.init();
  });  
  

Answer 2

You need to add CONNECTION as a provider to your test app: TestingModule =

await Test.createTestingModule({
  imports: [AppModule],
  providers: [
    { provide: CONNECTION, getRepository: jest.fn() },
  ],
}).compile();