ad/src/libs/tests/unit/db/prisma-repository.base.spec.ts

import { ResponseBase } from '@libs/api/response.base';
import { PrismaRepositoryBase } from '@libs/db/prisma-repository.base';
import { PrismaService } from '@libs/db/prisma.service';
import { AggregateID, AggregateRoot, Mapper, RepositoryPort } from '@libs/ddd';
import {
  ConflictException,
  DatabaseErrorException,
  NotFoundException,
} from '@libs/exceptions';
import { Injectable, Logger } from '@nestjs/common';
import { EventEmitter2 } from '@nestjs/event-emitter';
import { Test, TestingModule } from '@nestjs/testing';
import { Prisma } from '@prisma/client';
import { v4 } from 'uuid';

interface FakeProps {
  name: string;
}

interface CreateFakeProps {
  name: string;
}

class FakeEntity extends AggregateRoot<FakeProps> {
  protected readonly _id: AggregateID;

  static create = (create: CreateFakeProps): FakeEntity => {
    const id = v4();
    const props: FakeProps = { ...create };
    const fake = new FakeEntity({ id, props });
    return fake;
  };

  validate(): void {
    // not implemented
  }
}

type FakeModel = {
  uuid: string;
  name: string;
  createdAt: Date;
  updatedAt: Date;
};

type FakeRepositoryPort = RepositoryPort<FakeEntity>;

class FakeResponseDto extends ResponseBase {
  name: string;
}

const fakeRecord: FakeModel = {
  uuid: 'd567ea3b-4981-43c9-9449-a409b5fa9fed',
  name: 'fakeName',
  createdAt: new Date('2023-06-28T16:02:00Z'),
  updatedAt: new Date('2023-06-28T16:02:00Z'),
};

let recordId = 2;
const recordUuid = 'uuid-';
const recordName = 'fakeName-';

const createRandomRecord = (): FakeModel => {
  const fakeRecord: FakeModel = {
    uuid: `${recordUuid}${recordId}`,
    name: `${recordName}${recordId}`,
    createdAt: new Date('2023-06-30T08:00:00Z'),
    updatedAt: new Date('2023-06-30T08:00:00Z'),
  };

  recordId++;

  return fakeRecord;
};

const fakeRecords: FakeModel[] = [];
Array.from({ length: 10 }).forEach(() => {
  fakeRecords.push(createRandomRecord());
});

@Injectable()
class FakeMapper
  implements Mapper<FakeEntity, FakeModel, FakeModel, FakeResponseDto>
{
  toPersistence = (entity: FakeEntity): FakeModel => {
    const copy = entity.getProps();
    const record: FakeModel = {
      uuid: copy.id,
      name: copy.name,
      createdAt: copy.createdAt,
      updatedAt: copy.updatedAt,
    };
    return record;
  };

  toDomain = (record: FakeModel): FakeEntity => {
    const entity = new FakeEntity({
      id: record.uuid,
      createdAt: new Date(record.createdAt),
      updatedAt: new Date(record.updatedAt),
      props: {
        name: record.name,
      },
    });
    return entity;
  };

  toResponse = (entity: FakeEntity): FakeResponseDto => {
    const props = entity.getProps();
    const response = new FakeResponseDto(entity);
    response.name = props.name;
    return response;
  };
}

@Injectable()
class FakePrismaService extends PrismaService {
  fake: any;
}

const mockPrismaService = {
  $queryRaw: jest
    .fn()
    .mockImplementationOnce(() => {
      return true;
    })
    .mockImplementation(() => {
      throw new Prisma.PrismaClientKnownRequestError('Database unavailable', {
        code: 'code',
        clientVersion: 'version',
      });
    })
    .mockImplementationOnce(() => {
      throw new Error();
    }),
  fake: {
    create: jest
      .fn()
      .mockResolvedValueOnce(fakeRecord)
      .mockImplementationOnce(() => {
        throw new Prisma.PrismaClientKnownRequestError('Already exists', {
          code: 'code',
          clientVersion: 'version',
        });
      })
      .mockImplementationOnce(() => {
        throw new Error('An unknown error');
      }),

    findUnique: jest.fn().mockImplementation(async (params?: any) => {
      let record: FakeModel;

      if (params?.where?.uuid) {
        record = fakeRecords.find(
          (record) => record.uuid === params?.where?.uuid,
        );
      }

      if (!record && params?.where?.uuid == 'uuid-triggering-error') {
        throw new Prisma.PrismaClientKnownRequestError('unknown request', {
          code: 'code',
          clientVersion: 'version',
        });
      }

      return record;
    }),
  },
};

@Injectable()
class FakeRepository
  extends PrismaRepositoryBase<FakeEntity, FakeModel, FakeModel>
  implements FakeRepositoryPort
{
  constructor(
    prisma: FakePrismaService,
    mapper: FakeMapper,
    eventEmitter: EventEmitter2,
  ) {
    super(
      prisma.fake,
      prisma,
      mapper,
      eventEmitter,
      new Logger(FakeRepository.name),
    );
  }
}

describe('PrismaRepositoryBase', () => {
  let fakeRepository: FakeRepository;
  let prisma: FakePrismaService;

  beforeAll(async () => {
    const module: TestingModule = await Test.createTestingModule({
      providers: [
        EventEmitter2,
        FakeRepository,
        FakeMapper,
        {
          provide: FakePrismaService,
          useValue: mockPrismaService,
        },
      ],
    }).compile();

    fakeRepository = module.get<FakeRepository>(FakeRepository);
    prisma = module.get<FakePrismaService>(FakePrismaService);
  });

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

  describe('insert', () => {
    it('should create a record', async () => {
      jest.spyOn(prisma.fake, 'create');

      await fakeRepository.insert(
        FakeEntity.create({
          name: 'someFakeName',
        }),
      );
      expect(prisma.fake.create).toHaveBeenCalledTimes(1);
    });

    it('should throw a ConflictException if record already exists', async () => {
      await expect(
        fakeRepository.insert(
          FakeEntity.create({
            name: 'someFakeName',
          }),
        ),
      ).rejects.toBeInstanceOf(ConflictException);
    });

    it('should throw an Error if an error occurs', async () => {
      await expect(
        fakeRepository.insert(
          FakeEntity.create({
            name: 'someFakeName',
          }),
        ),
      ).rejects.toBeInstanceOf(Error);
    });
  });

  describe('findOneById', () => {
    it('should find a record by its id', async () => {
      const record = await fakeRepository.findOneById('uuid-3');
      expect(record.getProps().name).toBe('fakeName-3');
    });

    it('should throw an Error for client error', async () => {
      await expect(
        fakeRepository.findOneById('uuid-triggering-error'),
      ).rejects.toBeInstanceOf(Error);
    });

    it('should throw a NotFoundException if id is not found', async () => {
      await expect(
        fakeRepository.findOneById('wrong-id'),
      ).rejects.toBeInstanceOf(NotFoundException);
    });
  });

  describe('healthCheck', () => {
    it('should return a healthy result', async () => {
      const res = await fakeRepository.healthCheck();
      expect(res).toBeTruthy();
    });

    it('should throw an exception if database is not available', async () => {
      await expect(fakeRepository.healthCheck()).rejects.toBeInstanceOf(
        DatabaseErrorException,
      );
    });

    it('should throw a DatabaseErrorException if an error occurs', async () => {
      await expect(fakeRepository.healthCheck()).rejects.toBeInstanceOf(
        DatabaseErrorException,
      );
    });
  });
});