create-react-app/fixtures/utils.js

const execa = require('execa');
const fs = require('fs-extra');
const getPort = require('get-port');
const path = require('path');
const os = require('os');
const stripAnsi = require('strip-ansi');

async function bootstrap({ directory, template }) {
  const shouldInstallScripts = process.env.CI && process.env.CI !== 'false';
  await Promise.all(
    ['public/', 'src/', 'package.json'].map(async file =>
      fs.copy(path.join(template, file), path.join(directory, file))
    )
  );
  if (shouldInstallScripts) {
    const packageJson = fs.readJsonSync(path.join(directory, 'package.json'));
    packageJson.dependencies = Object.assign({}, packageJson.dependencies, {
      'react-scripts': 'latest',
    });
    fs.writeJsonSync(path.join(directory, 'package.json'), packageJson);
  }
  await execa('yarnpkg', ['install', '--mutex', 'network'], { cwd: directory });
  if (!shouldInstallScripts) {
    fs.ensureSymlinkSync(
      path.resolve(
        path.join(
          __dirname,
          '..',
          'packages',
          'react-scripts',
          'bin',
          'react-scripts.js'
        )
      ),
      path.join(directory, 'node_modules', '.bin', 'react-scripts')
    );
    await execa('yarnpkg', ['link', 'react-scripts'], { cwd: directory });
  }
}

async function isSuccessfulDevelopment({ directory }) {
  const { stdout, stderr } = await execa(
    './node_modules/.bin/react-scripts',
    ['start', '--smoke-test'],
    {
      cwd: directory,
      env: { BROWSER: 'none', PORT: await getPort() },
    }
  );

  if (!/Compiled successfully/.test(stdout)) {
    throw new Error(`stdout: ${stdout}${os.EOL + os.EOL}stderr: ${stderr}`);
  }
}

async function isSuccessfulProduction({ directory }) {
  const { stdout, stderr } = await execa(
    './node_modules/.bin/react-scripts',
    ['build'],
    {
      cwd: directory,
    }
  );

  if (!/Compiled successfully/.test(stdout)) {
    throw new Error(`stdout: ${stdout}${os.EOL + os.EOL}stderr: ${stderr}`);
  }
}

async function isSuccessfulTest({ directory, jestEnvironment = 'jsdom' }) {
  await execa(
    './node_modules/.bin/react-scripts',
    ['test', '--env', jestEnvironment, '--ci'],
    {
      cwd: directory,
      env: { CI: 'true' },
    }
  );
}

async function getOutputDevelopment({ directory, env = {} }) {
  try {
    const { stdout, stderr } = await execa(
      './node_modules/.bin/react-scripts',
      ['start', '--smoke-test'],
      {
        cwd: directory,
        env: Object.assign(
          {},
          {
            BROWSER: 'none',
            PORT: await getPort(),
            CI: 'false',
            FORCE_COLOR: '0',
          },
          env
        ),
      }
    );
    return { stdout: stripAnsi(stdout), stderr: stripAnsi(stderr) };
  } catch (err) {
    return {
      stdout: '',
      stderr: stripAnsi(
        err.message
          .split(os.EOL)
          .slice(2)
          .join(os.EOL)
      ),
    };
  }
}

async function getOutputProduction({ directory, env = {} }) {
  try {
    const { stdout, stderr } = await execa(
      './node_modules/.bin/react-scripts',
      ['build'],
      {
        cwd: directory,
        env: Object.assign({}, { CI: 'false', FORCE_COLOR: '0' }, env),
      }
    );
    return { stdout: stripAnsi(stdout), stderr: stripAnsi(stderr) };
  } catch (err) {
    return {
      stdout: '',
      stderr: stripAnsi(
        err.message
          .split(os.EOL)
          .slice(2)
          .join(os.EOL)
      ),
    };
  }
}

module.exports = {
  bootstrap,
  isSuccessfulDevelopment,
  isSuccessfulProduction,
  isSuccessfulTest,
  getOutputDevelopment,
  getOutputProduction,
};