• Joe Haddad's avatar
    Turn on Babel `helpers` (#5093) · adfb20c4
    Joe Haddad authored
    * Turn on helpers and test importing something with async/await works
    
    * Compiling babel runtime breaks itself
    
    * Add helpers option to babel plugin with defaults
    
    * Make helpers off by default and on in our configuration
    
    * Hit eject and e2e
    
    * meh
    
    * copy'n'paste
    
    * change again
    
    * Turn off helpers by default in /prod, /dev, /test
    
    * oops
    
    * Spread undefined
    
    * Use object assign not object spread
    
    * Put preset in template since it's needed
    
    * Fix e2e tests
    Unverified
    adfb20c4
start.js 10.01 KiB
/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
process.env.NODE_ENV = 'development';
var path = require('path');
var chalk = require('chalk');
var webpack = require('webpack');
var WebpackDevServer = require('webpack-dev-server');
var historyApiFallback = require('connect-history-api-fallback');
var httpProxyMiddleware = require('http-proxy-middleware');
var execSync = require('child_process').execSync;
var opn = require('opn');
var detect = require('detect-port');
var prompt = require('./utils/prompt');
var config = require('../config/webpack.config.dev');
var paths = require('../config/paths');
// Tools like Cloud9 rely on this.
var DEFAULT_PORT = process.env.PORT || 3000;
var compiler;
// TODO: hide this behind a flag and eliminate dead code on eject.
// This shouldn't be exposed to the user.
var handleCompile;
var isSmokeTest = process.argv.some(arg => arg.indexOf('--smoke-test') > -1);
if (isSmokeTest) {
  handleCompile = function (err, stats) {
    if (err || stats.hasErrors() || stats.hasWarnings()) {
      process.exit(1);
    } else {
      process.exit(0);
// Some custom utilities to prettify Webpack output.
// This is a little hacky.
// It would be easier if webpack provided a rich error object.
var friendlySyntaxErrorLabel = 'Syntax error:';
function isLikelyASyntaxError(message) {
  return message.indexOf(friendlySyntaxErrorLabel) !== -1;
function formatMessage(message) {
  return message
    // Make some common errors shorter:
    .replace(
      // Babel syntax error
      'Module build failed: SyntaxError:',
      friendlySyntaxErrorLabel
    .replace(
      // Webpack file not found error
      /Module not found: Error: Cannot resolve 'file' or 'directory'/,
      'Module not found:'
    // Internal stacks are generally useless so we strip them
    .replace(/^\s*at\s.*:\d+:\d+[\s\)]*\n/gm, '') // at ... ...:x:y
    // Webpack loader names obscure CSS filenames
    .replace('./~/css-loader!./~/postcss-loader!', '');
function clearConsole() {
  // This seems to work best on Windows and other systems.
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// The intention is to clear the output so you can focus on most recent build. process.stdout.write('\x1bc'); } function setupCompiler(port) { // "Compiler" is a low-level interface to Webpack. // It lets us listen to some events and provide our own custom messages. compiler = webpack(config, handleCompile); // "invalid" event fires when you have changed a file, and Webpack is // recompiling a bundle. WebpackDevServer takes care to pause serving the // bundle, so if you refresh, it'll wait instead of serving the old one. // "invalid" is short for "bundle invalidated", it doesn't imply any errors. compiler.plugin('invalid', function() { clearConsole(); console.log('Compiling...'); }); // "done" event fires when Webpack has finished recompiling the bundle. // Whether or not you have warnings or errors, you will get this event. compiler.plugin('done', function(stats) { clearConsole(); var hasErrors = stats.hasErrors(); var hasWarnings = stats.hasWarnings(); if (!hasErrors && !hasWarnings) { console.log(chalk.green('Compiled successfully!')); console.log(); console.log('The app is running at:'); console.log(); console.log(' ' + chalk.cyan('http://localhost:' + port + '/')); console.log(); console.log('Note that the development build is not optimized.'); console.log('To create a production build, use ' + chalk.cyan('npm run build') + '.'); console.log(); return; } // We have switched off the default Webpack output in WebpackDevServer // options so we are going to "massage" the warnings and errors and present // them in a readable focused way. var json = stats.toJson(); var formattedErrors = json.errors.map(message => 'Error in ' + formatMessage(message) ); var formattedWarnings = json.warnings.map(message => 'Warning in ' + formatMessage(message) ); if (hasErrors) { console.log(chalk.red('Failed to compile.')); console.log(); if (formattedErrors.some(isLikelyASyntaxError)) { // If there are any syntax errors, show just them. // This prevents a confusing ESLint parsing error // preceding a much more useful Babel syntax error. formattedErrors = formattedErrors.filter(isLikelyASyntaxError); } formattedErrors.forEach(message => { console.log(message); console.log(); }); // If errors exist, ignore warnings. return; } if (hasWarnings) { console.log(chalk.yellow('Compiled with warnings.')); console.log(); formattedWarnings.forEach(message => { console.log(message); console.log(); });
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// Teach some ESLint tricks. console.log('You may use special comments to disable some warnings.'); console.log('Use ' + chalk.yellow('// eslint-disable-next-line') + ' to ignore the next line.'); console.log('Use ' + chalk.yellow('/* eslint-disable */') + ' to ignore all warnings in a file.'); } }); } function openBrowser(port) { if (process.platform === 'darwin') { try { // Try our best to reuse existing tab // on OS X Google Chrome with AppleScript execSync('ps cax | grep "Google Chrome"'); execSync( 'osascript chrome.applescript http://localhost:' + port + '/', {cwd: path.join(__dirname, 'utils'), stdio: 'ignore'} ); return; } catch (err) { // Ignore errors. } } // Fallback to opn // (It will always open new tab) opn('http://localhost:' + port + '/'); } function addMiddleware(devServer) { // `proxy` lets you to specify a fallback server during development. // Every unrecognized request will be forwarded to it. var proxy = require(paths.appPackageJson).proxy; devServer.use(historyApiFallback({ // For single page apps, we generally want to fallback to /index.html. // However we also want to respect `proxy` for API calls. // So if `proxy` is specified, we need to decide which fallback to use. // We use a heuristic: if request `accept`s text/html, we pick /index.html. // Modern browsers include text/html into `accept` header when navigating. // However API calls like `fetch()` won’t generally won’t accept text/html. // If this heuristic doesn’t work well for you, don’t use `proxy`. htmlAcceptHeaders: proxy ? ['text/html'] : ['text/html', '*/*'] })); if (proxy) { if (typeof proxy !== 'string') { console.log(chalk.red('When specified, "proxy" in package.json must be a string.')); console.log(chalk.red('Instead, the type of "proxy" was "' + typeof proxy + '".')); console.log(chalk.red('Either remove "proxy" from package.json, or make it a string.')); process.exit(1); } // Otherwise, if proxy is specified, we will let it handle any request. // There are a few exceptions which we won't send to the proxy: // - /index.html (served as HTML5 history API fallback) // - /*.hot-update.json (WebpackDevServer uses this too for hot reloading) // - /sockjs-node/* (WebpackDevServer uses this for hot reloading) // Tip: use https://www.debuggex.com/ to visualize the regex var mayProxy = /^(?!\/(index\.html$|.*\.hot-update\.json$|sockjs-node\/)).*$/; devServer.use(mayProxy, // Pass the scope regex both to Express and to the middleware for proxying // of both HTTP and WebSockets to work without false positives. httpProxyMiddleware(pathname => mayProxy.test(pathname), { target: proxy, logLevel: 'silent', secure: false, changeOrigin: true }) ); }
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// Finally, by now we have certainly resolved the URL. // It may be /index.html, so let the dev server try serving it again. devServer.use(devServer.middleware); } function runDevServer(port) { var devServer = new WebpackDevServer(compiler, { // Enable hot reloading server. It will provide /sockjs-node/ endpoint // for the WebpackDevServer client so it can learn when the files were // updated. The WebpackDevServer client is included as an entry point // in the Webpack development configuration. Note that only changes // to CSS are currently hot reloaded. JS changes will refresh the browser. hot: true, // It is important to tell WebpackDevServer to use the same "root" path // as we specified in the config. In development, we always serve from /. publicPath: config.output.publicPath, // WebpackDevServer is noisy by default so we emit custom message instead // by listening to the compiler events with `compiler.plugin` calls above. quiet: true, // Reportedly, this avoids CPU overload on some systems. // https://github.com/facebookincubator/create-react-app/issues/293 watchOptions: { ignored: /node_modules/ } }); // Our custom middleware proxies requests to /index.html or a remote API. addMiddleware(devServer); // Launch WebpackDevServer. devServer.listen(port, (err, result) => { if (err) { return console.log(err); } clearConsole(); console.log(chalk.cyan('Starting the development server...')); console.log(); openBrowser(port); }); } function run(port) { setupCompiler(port); runDevServer(port); } // We attempt to use the default port but if it is busy, we offer the user to // run on a different port. `detect()` Promise resolves to the next free port. detect(DEFAULT_PORT).then(port => { if (port === DEFAULT_PORT) { run(port); return; } clearConsole(); var question = chalk.yellow('Something is already running on port ' + DEFAULT_PORT + '.') + '\n\nWould you like to run the app on another port instead?'; prompt(question, true).then(shouldChangePort => { if (shouldChangePort) { run(port); } }); });