'use strict'; // 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('react-dev-utils/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 semver = require('semver'); const paths = require('../config/paths'); const configFactory = require('../config/webpack.config'); const createDevServerConfig = require('../config/webpackDevServer.config'); const getClientEnvironment = require('../config/env'); const react = require(require.resolve('react', { paths: [paths.appPath] })); const env = getClientEnvironment(paths.publicUrlOrPath.slice(0, -1)); 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('https://cra.link/advanced-config')}` ); console.log(); } // We require that you explicitly set browsers and do not fall back to // browserslist defaults. const { checkBrowsers } = require('react-dev-utils/browsersHelper'); checkBrowsers(paths.appPath, isInteractive) .then(() => { // 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. return choosePort(HOST, DEFAULT_PORT); }) .then(port => { if (port == null) { // We have not found a port. return; } const config = configFactory('development'); const protocol = process.env.HTTPS === 'true' ? 'https' : 'http'; const appName = require(paths.appPackageJson).name; const useTypeScript = fs.existsSync(paths.appTsConfig); const urls = prepareUrls( protocol, HOST, port, paths.publicUrlOrPath.slice(0, -1) ); // Create a webpack compiler that is configured with custom messages. const compiler = createCompiler({ appName, config, urls, useYarn, useTypeScript, webpack, }); // Load proxy config const proxySetting = require(paths.appPackageJson).proxy; const proxyConfig = prepareProxy( proxySetting, paths.appPublic, paths.publicUrlOrPath ); // Serve webpack assets generated by the compiler over a web server. const serverConfig = { ...createDevServerConfig(proxyConfig, urls.lanUrlForConfig), host: HOST, port, }; const devServer = new WebpackDevServer(serverConfig, compiler); // Launch WebpackDevServer. devServer.startCallback(() => { if (isInteractive) { clearConsole(); } if (env.raw.FAST_REFRESH && semver.lt(react.version, '16.10.0')) { console.log( chalk.yellow( `Fast Refresh requires React 16.10 or higher. You are using React ${react.version}.` ) ); } console.log(chalk.cyan('Starting the development server...\n')); openBrowser(urls.localUrlForBrowser); }); ['SIGINT', 'SIGTERM'].forEach(function (sig) { process.on(sig, function () { devServer.close(); process.exit(); }); }); if (process.env.CI !== 'true') { // Gracefully exit when stdin ends process.stdin.on('end', function () { devServer.close(); process.exit(); }); } }) .catch(err => { if (err && err.message) { console.log(err.message); } process.exit(1); });