build.js — react Source File

Source Code

'use strict';

// Do this as the first thing so that any code reading it knows the right env.
process.env.BABEL_ENV = 'production';
process.env.NODE_ENV = 'production';

// 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 path = require('path');
const chalk = require('chalk');
const fs = require('fs-extra');
const webpack = require('webpack');
const configFactory = require('../config/webpack.config');
const paths = require('../config/paths');
const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
const formatWebpackMessages = require('react-dev-utils/formatWebpackMessages');
const printHostingInstructions = require('react-dev-utils/printHostingInstructions');
const FileSizeReporter = require('react-dev-utils/FileSizeReporter');
const printBuildError = require('react-dev-utils/printBuildError');

const measureFileSizesBeforeBuild =
  FileSizeReporter.measureFileSizesBeforeBuild;
const printFileSizesAfterBuild = FileSizeReporter.printFileSizesAfterBuild;
const useYarn = fs.existsSync(paths.yarnLockFile);

// These sizes are pretty large. We'll warn for bundles exceeding them.
const WARN_AFTER_BUNDLE_GZIP_SIZE = 512 * 1024;
const WARN_AFTER_CHUNK_GZIP_SIZE = 1024 * 1024;

const isInteractive = process.stdout.isTTY;

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

const argv = process.argv.slice(2);
const writeStatsJson = argv.indexOf('--stats') !== -1;

// Generate configuration
const config = configFactory('production');

// 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(() => {
    // First, read the current file sizes in build directory.
    // This lets us display how much they changed later.
    return measureFileSizesBeforeBuild(paths.appBuild);
  })
  .then(previousFileSizes => {
// ... (149 more lines)