derma/tests/create_images_directory.test.js

import { create_images_directory } from '../src/logic';

beforeEach(jest.restoreAllMocks);

const fs = require('fs').promises;
const filesystem = require('fs');

describe('create_images_directory', () => {
  it('creates images directory', () => {
    const mock = jest
      .spyOn(fs, 'mkdir')
      .mockImplementation(() => Promise.resolve());
    jest.spyOn(filesystem, 'existsSync').mockImplementation(() => false);
    const dir = 'new directory';
    expect.assertions(2);
    return create_images_directory(dir).then(() => {
      expect(mock).toHaveBeenCalledTimes(1);
      expect(mock).toHaveBeenCalledWith(dir, { recursive: true });
    });
  });

  it('it skips creating images directory', () => {
    const fs_mock = jest
      .spyOn(fs, 'mkdir')
      .mockImplementation(() => Promise.resolve());
    const exist_mock = jest
      .spyOn(filesystem, 'existsSync')
      .mockImplementation(() => true);
    const dir = 'new directory';
    expect.assertions(3);
    return create_images_directory(dir).then(() => {
      expect(fs_mock).toHaveBeenCalledTimes(0);
      expect(exist_mock).toHaveBeenCalledTimes(1);
      expect(exist_mock).toHaveBeenCalledWith(dir);
    });
  });

  [undefined, null].forEach((dir) =>
    it('throws if directory is not set', () => {
      const mock = jest
        .spyOn(filesystem, 'existsSync')
        .mockImplementation(() => true);
      expect.assertions(2);
      return create_images_directory(dir).catch((error) => {
        expect(mock).toHaveBeenCalledTimes(0);
        expect(error).toEqual('Image path was not set');
      });
    }),
  );
});