[NEW TEST] Sequelize transactions

[c-kirkeby]

Is there an existing issue for this?

• [X] I have searched the existing issues

Feature Test To Be Requested

The sequelize-sample is really awesome, but we're using Sequelize Transactions in our codebase and by doing so we have to mock the Sequelize transaction() method or Nest will throw dependency errors:

Nest can't resolve dependencies of the CatService (CatEntityRepository, ?). Please make sure that the argument Sequelize at index [5] is available in the RootTestModule context.

Potential solutions:
- Is RootTestModule a valid NestJS module?
- If Sequelize is a provider, is it part of the current RootTestModule?
- If Sequelize is exported from a separate @Module, is that module imported within RootTestModule?
  @Module({
    imports: [ /* the Module containing Sequelize */ ]
  })

I've looked through the NestJS documentation and Discord but I couldn't find any good examples of how to do this because if I mock the Sequelize transaction like this, I don't get the value from my service call:

        {
          provide: Sequelize,
          useValue: {
            transaction: jest.fn(() => Promise.resolve()),
          },
        },

The Nest docs state to use a helper factory class but I couldn't find a good example of this either.

[1111mp]

Is this solution correct? I don't think I'm writing code for automated testing, just trying to piece together code that doesn't report errors. : (

users.service.ts:

@Injectable()
export class UsersService {
  constructor(
    private readonly sequelize: Sequelize,
    @InjectModel(User)
    private readonly userModel: typeof User,
    @Inject(IORedisKey) private readonly redisClient: Redis,
  ) {}

  // ......

  async getUserModel(id: number): Promise<User> {
    return this.userModel.findOne({
      attributes: { exclude: ['pwd'] },
      where: { id },
    });
  }

  async findByAccount(account: string): Promise<User.UserInfo | null> {
    const trans = await this.sequelize.transaction();
    const user = await this.userModel.findOne({
      where: {
        account,
      },
      transaction: trans,
    });

    if (!user) return null;

    const role = await user.$get('role', { transaction: trans });
    const permissions = (
      await role.$get('permissions', { transaction: trans })
    ).map(({ id, name, desc }) => ({
      id,
      name,
      desc,
    }));

    await trans.commit();

    const { id: roleId, name: roleName, desc: roleDesc } = role;

    return {
      ...user.toJSON(),
      roleId,
      roleName,
      roleDesc,
      permissions,
    };
  }

 // ......
}

users.service.spec.ts:

import { Test, TestingModule } from '@nestjs/testing';
import { getModelToken } from '@nestjs/sequelize';
import { UsersService } from './users.service';
import { User as UserModel } from './models/user.model';
import { IORedisKey } from 'src/common/redis/redis.module';

import type { Redis } from 'ioredis';
import { Sequelize } from 'sequelize-typescript';

const testUser = {
  id: 10007,
  account: '176******',
  avatar: 'avatar.png',
  email: 'test@gmail.com',
  regisTime: '2023-01-28 12:16:06',
  updateTime: '2023-01-29 14:01:35',
};

const testRole = {
  id: 5,
  name: 'admin',
  desc: '管理员',
};

const testPermissions = {
  id: 1,
  name: 'userDel',
  desc: 'Delete user',
};

describe('UsersService', () => {
  let service: UsersService,
    model: typeof UserModel,
    redisClient: Redis,
    sequelize: Sequelize;

  beforeEach(async () => {
    const module: TestingModule = await Test.createTestingModule({
      providers: [
        UsersService,
        {
          provide: Sequelize,
          useValue: {
            transaction: jest.fn(),
          },
        },
        {
          provide: getModelToken(UserModel),
          useValue: {
            findOne: jest.fn(),
            create: jest.fn(() => testUser),
          },
        },
        { provide: IORedisKey, useValue: {} },
      ],
    }).compile();

    service = module.get<UsersService>(UsersService);
    model = module.get<typeof UserModel>(getModelToken(UserModel));
    redisClient = module.get<Redis>(IORedisKey);
    sequelize = module.get<Sequelize>(Sequelize);
  });

  afterEach(() => {
    jest.restoreAllMocks();
  });

  it('should be defined', () => {
    expect(service).toBeDefined();
  });

  it('should get a single user by the method named getUserModel', () => {
    const findSpy = jest.spyOn(model, 'findOne');

    expect(service.getUserModel(10007));
    expect(findSpy).toBeCalledWith({
      attributes: { exclude: ['pwd'] },
      where: { id: 10007 },
    });
  });

  test('the method named findByAccount', async () => {
    // mock transaction
    const commit = jest.fn();
    const transaction = jest.fn(async () => ({ commit }) as any);
    const transSpy = jest
      .spyOn(sequelize, 'transaction')
      .mockImplementation(transaction);

    const permissionsStub = jest.fn(() => ({
        map: jest.fn(() => [testPermissions]),
      })),
      roleStub = jest.fn((key: string) => ({
        ...testRole,
        $get: permissionsStub,
      }));
    const findSpy = jest.spyOn(model, 'findOne').mockReturnValue({
      $get: roleStub,
      toJSON: jest.fn(() => testUser),
    } as any);

    const retVal = await service.findByAccount('176********');

    expect(transSpy).toBeCalledTimes(1);
    expect(findSpy).toBeCalledWith({
      where: { account: '176********' },
      transaction: await transaction(),
    });
    expect(commit).toBeCalledTimes(1);

    const { id: roleId, name: roleName, desc: roleDesc } = testRole;

    expect(retVal).toEqual({
      ...testUser,
      roleId,
      roleName,
      roleDesc,
      permissions: [testPermissions],
    });
  });
});

These codes look kind of stupid ...... Can anyone suggest the correct solution (or any idea).