aihub-web/scripts/start.js

/*eslint-disable no-console */
// Do this as the first thing so that any code reading it knows the right env.
process.env.BABEL_ENV = 'development';
process.env.NODE_ENV = 'development';

// Makes the script crash on unhandled rejections instead of silently
// ignoring them. In the future, promise rejections that are not handled will
// terminate the Node.js process with a non-zero exit code.
process.on('unhandledRejection', err => {
  throw err;
});

// Ensure environment variables are read.
require('../config/env');

const fs = require('fs');
const chalk = require('chalk');
const webpack = require('webpack');
const WebpackDevServer = require('webpack-dev-server');
const clearConsole = require('react-dev-utils/clearConsole');
const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
const { choosePort, createCompiler, prepareProxy, prepareUrls } = require('react-dev-utils/WebpackDevServerUtils');
const openBrowser = require('react-dev-utils/openBrowser');
const paths = require('../config/paths');
const config = require('../config/webpack.config.dev');
const createDevServerConfig = require('../config/webpack.config.devserver');

const useYarn = fs.existsSync(paths.yarnLockFile);
const isInteractive = process.stdout.isTTY;

// Warn and crash if required files are missing
if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
  process.exit(1);
}

// Tools like Cloud9 rely on this.
const DEFAULT_PORT = parseInt(process.env.PORT, 10) || 3000;
const HOST = process.env.HOST || '0.0.0.0';

if (process.env.HOST) {
  console.log(
    chalk.cyan(`Attempting to bind to HOST environment variable: ${chalk.yellow(chalk.bold(process.env.HOST))}`)
  );
  console.log(`If this was unintentional, check that you haven't mistakenly set it in your shell.`);
  console.log(`Learn more here: ${chalk.yellow('http://bit.ly/2mwWSwH')}`);
  console.log();
}

// We attempt to use the default port but if it is busy, we offer the user to
// run on a different port. `choosePort()` Promise resolves to the next free port.
choosePort(HOST, DEFAULT_PORT)
  .then(port => {
    if (port == null) {
      // We have not found a port.
      return;
    }
    const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
    const appName = require(paths.appPackageJson).name;
    const urls = prepareUrls(protocol, HOST, port);
    // Create a webpack compiler that is configured with custom messages.
    const compiler = createCompiler(webpack, config, appName, urls, useYarn);
    // Load proxy config
    const proxySetting = require(paths.appPackageJson).proxy;
    const proxyConfig = prepareProxy(proxySetting, paths.appPublic);
    // Serve webpack assets generated by the compiler over a web sever.
    const serverConfig = createDevServerConfig(proxyConfig, urls.lanUrlForConfig);
    const devServer = new WebpackDevServer(compiler, serverConfig);
    // Launch WebpackDevServer.
    devServer.listen(port, HOST, err => {
      if (err) {
        return console.log(err);
      }
      if (isInteractive) {
        // clearConsole();
      }
      console.log(chalk.cyan('Starting the development server...\n'));

      openBrowser(urls.localUrlForBrowser);
    });

    ['SIGINT', 'SIGTERM'].forEach(sig => {
      process.on(sig, () => {
        devServer.close();
        process.exit();
      });
    });
  })
  .catch(err => {
    if (err && err.message) {
      console.log(err.message);
    }
    process.exit(1);
  });