INTO-CPS-Association/DTaaS

import { Test, TestingModule } from '@nestjs/testing';
import FilesResolver from '../../src/files/resolvers/files.resolver';
import {
  testDirectory,
  pathToTestDirectory,
  pathToTestFileContent,
  testFileContent,
} from '../testUtil';
import { IFilesService } from '../../src/files/interfaces/files.service.interface';
import FilesServiceFactory from '../../src/files/services/files-service.factory';

describe('Unit tests for FilesResolver', () => {
  let filesResolver: FilesResolver;
  let filesService: IFilesService;

  beforeEach(async () => {
    const mockFilesService: IFilesService = {
      listDirectory: jest.fn().mockImplementation(() => testDirectory),
      readFile: jest.fn().mockImplementation(() => testFileContent),
    };

    const module: TestingModule = await Test.createTestingModule({
      providers: [
        FilesResolver,
        FilesServiceFactory,
        {
          provide: FilesServiceFactory,
          useValue: {
            create: () => mockFilesService,
          },
        },
      ],
    }).compile();

    filesResolver = module.get<FilesResolver>(FilesResolver);
    filesService = module
      .get<FilesServiceFactory>(FilesServiceFactory)
      .create();
  });

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

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

    it('should list files in directory', async () => {
      const result = await filesResolver.listDirectory(pathToTestDirectory);
      expect(result).toEqual(testDirectory);
      expect(filesService.listDirectory).toHaveBeenCalledWith(
        pathToTestDirectory,
      );
    });
  });

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

    it('should read file', async () => {
      const result = await filesResolver.readFile(pathToTestFileContent);
      expect(result).toEqual(testFileContent);
      expect(filesService.readFile).toHaveBeenCalledWith(pathToTestFileContent);
    });
  });
});