"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 tscCompileOnError = process.env.TSC_COMPILE_ON_ERROR === "true"; const urls = prepareUrls( protocol, HOST, port, paths.publicUrlOrPath.slice(0, -1) ); const devSocket = { warnings: (warnings) => devServer.sockWrite(devServer.sockets, "warnings", warnings), errors: (errors) => devServer.sockWrite(devServer.sockets, "errors", errors), }; // Create a webpack compiler that is configured with custom messages. const compiler = createCompiler({ appName, config, devSocket, urls, useYarn, useTypeScript, tscCompileOnError, 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 ); const devServer = new WebpackDevServer(compiler, serverConfig); // Launch WebpackDevServer. devServer.listen(port, HOST, (err) => { if (err) { return console.log(err); } 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); });