@vitbokisch/next-optimized-images/__tests__/loaders/index.test.js

Automatically optimize images used in next.js projects (jpeg, png, gif, svg).

const {
  isModuleInstalled,
  detectLoaders,
  getHandledImageTypes,
  getNumOptimizationLoadersInstalled,
  appendLoaders,
} = require('../../lib/loaders');
const { getConfig } = require('../../lib/config');

module.exports = () => () => ({ plugin: true });

describe('next-optimized-images/loaders', () => {
  it('detects if a module is installed', () => {
    expect(isModuleInstalled('path')).toEqual(true);
    expect(isModuleInstalled('pathalksdfjladksfj')).toEqual(false);
    expect(isModuleInstalled('img-loader.test.js')).toEqual(false);
    expect(isModuleInstalled('img-loader.test.js', __dirname)).toEqual(true);
  });

  it('detects installed loaders', () => {
    expect(detectLoaders()).toEqual({
      jpeg: false,
      gif: false,
      svg: false,
      svgSprite: 'svg-sprite-loader', // is in the devDependencies
      webp: false,
      png: false,
      lqip: false,
      responsive: false,
      responsiveAdapter: false,
    });
  });

  it('returns the handled image types', () => {
    expect(getHandledImageTypes(getConfig({}))).toEqual({
      jpeg: true,
      png: true,
      svg: true,
      webp: true,
      gif: true,
      ico: false,
    });

    expect(getHandledImageTypes(getConfig({ handleImages: ['jpg', 'png', 'ico'] }))).toEqual({
      jpeg: true,
      png: true,
      svg: false,
      webp: false,
      gif: false,
      ico: true,
    });

    expect(getHandledImageTypes(getConfig({ handleImages: [] }))).toEqual({
      jpeg: false,
      png: false,
      svg: false,
      webp: false,
      gif: false,
      ico: false,
    });
  });

  it('counts the number of optimization loaders', () => {
    expect(getNumOptimizationLoadersInstalled({
      jpeg: 'imagemin-jpeg',
      png: 'imagemin-png',
      svgSprite: 'svg-sprite-loader',
    })).toEqual(2);
  });

  it('appends loaders to the webpack config', () => {
    const webpackConfig = { module: { rules: [] } };

    appendLoaders(webpackConfig, getConfig({}), {
      jpeg: __filename,
      webp: __filename,
    }, false, true);

    expect(webpackConfig.module.rules).toHaveLength(2);
  });
});