Trouble testing service that connects to database about foal HOT 5 CLOSED

describe('UserService', () => {

  let service: UserService;
  let connection: Connection;

  // Create a connection to the database before running all the tests.
  before(async () => {
    connection = await createConnection({
      // Choose a test database. You don't want to run your tests on your production data.
      database: './test_db.sqlite3',
      // Drop the schema when the connection is established.
      dropSchema: true,
      // Register the models that are used.
      entities: [ User ],
      // Auto create the database schema.
      synchronize: true,
      // Specify the type of database.
      type: 'sqlite',
    });
    const user = new User();
    user.name = 'Mary';
    await connection.manager.save(user);
  });

  // Close the database connection after running all the tests whether they succeed or failed.
  after(() => connection.close());

  it('should have a getUsers method which returns the users of the database', async () => {
    service = createService(UserService);
    const users = await service.getUsers();
    
    strictEqual(users.length, 1);
    strictEqual(users[0].name, 'Mary');
  });

});

// my-other.service.ts
class MyOtherService {
  @dependency
  userService: UserService
}

// my-other.service.spec.ts
class MockUserService {
   async getUsers() {
    return [];
  }
}

...
myOtherService = createService(MyOtherService, { userService: MockUserService }); 
...

    /**
     * Clears all the data from the given table/collection (truncates/drops it).
     *
     * Note: this method uses TRUNCATE and may not work as you expect in transactions on some platforms.
     * @see https://stackoverflow.com/a/5972738/925151
     */
    clear(): Promise<void>;