TestCases.test.js

import fs from 'fs';
import path from 'path';
import { exec } from 'child_process';

import webpack from 'webpack';

describe('TestCases', () => {
  const casesDirectory = path.resolve(__dirname, 'cases');
  const outputDirectory = path.resolve(__dirname, 'js');
  for (const directory of fs.readdirSync(casesDirectory)) {
    if (!/^(\.|_)/.test(directory)) {
      // eslint-disable-next-line no-loop-func
      it(`${directory} should compile to the expected result`, (done) => {
        const directoryForCase = path.resolve(casesDirectory, directory);
        const outputDirectoryForCase = path.resolve(outputDirectory, directory);
        // eslint-disable-next-line import/no-dynamic-require, global-require
        const webpackConfig = require(path.resolve(
          directoryForCase,
          'webpack.config.js'
        ));
        for (const config of [].concat(webpackConfig)) {
          Object.assign(
            config,
            {
              mode: 'none',
              context: directoryForCase,
              output: Object.assign(
                {
                  path: outputDirectoryForCase,
                },
                config.output
              ),
            },
            config
          );
        }
        webpack(webpackConfig, (err, stats) => {
          if (err) {
            done(err);
            return;
          }
          done();
          // eslint-disable-next-line no-console
          console.log(
            stats.toString({
              context: path.resolve(__dirname, '..'),
              chunks: true,
              chunkModules: true,
              modules: false,
            })
          );
          if (stats.hasErrors()) {
            done(
              new Error(
                stats.toString({
                  context: path.resolve(__dirname, '..'),
                  errorDetails: true,
                })
              )
            );
            return;
          }
          const expectedDirectory = path.resolve(directoryForCase, 'expected');
          for (const file of fs.readdirSync(expectedDirectory)) {
            const content = fs.readFileSync(
              path.resolve(expectedDirectory, file),
              'utf-8'
            );
            const actualContent = fs.readFileSync(
              path.resolve(outputDirectoryForCase, file),
              'utf-8'
            );
            expect(actualContent).toEqual(content);
          }
          done();
        });
      }, 10000);
    }
  }
});

describe('HMR', () => {
  it('matches snapshot', () => {
    const hmr = fs
      .readFileSync(path.join(__dirname, '../src/hmr/hotModuleReplacement.js'))
      .toString();

    expect(hmr).toMatchSnapshot();
  });

  it('is es5 only', () => {
    exec(
      './node_modules/.bin/es-check es5 src/hmr/hotModuleReplacement.js',
      (error, stdout, stderr) => {
        expect(
          stderr.indexOf('there were no ES version matching errors!') > -1
        ).toBe(true);
      }
    );
  });
});