FileSizeReporter.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

'use strict';

var fs = require('fs');
var path = require('path');
var chalk = require('chalk');
var filesize = require('filesize');
var recursive = require('recursive-readdir');
var stripAnsi = require('strip-ansi');
var gzipSize = require('gzip-size').sync;

// Prints a detailed summary of build files.
function printFileSizesAfterBuild(
  webpackStats,
  previousSizeMap,
  buildFolder,
  maxBundleGzipSize,
  maxChunkGzipSize
) {
  var root = previousSizeMap.root;
  var sizes = previousSizeMap.sizes;
  var assets = (webpackStats.stats || [webpackStats])
    .map(stats =>
      stats
        .toJson()
        .assets.filter(asset => /\.(js|css)$/.test(asset.name))
        .map(asset => {
          var fileContents = fs.readFileSync(path.join(root, asset.name));
          var size = gzipSize(fileContents);
          var previousSize = sizes[removeFileNameHash(root, asset.name)];
          var difference = getDifferenceLabel(size, previousSize);
          return {
            folder: path.join(
              path.basename(buildFolder),
              path.dirname(asset.name)
            ),
            name: path.basename(asset.name),
            size: size,
            sizeLabel:
              filesize(size) + (difference ? ' (' + difference + ')' : '')
          };
        })
    )
    .reduce((single, all) => all.concat(single), []);
  assets.sort((a, b) => b.size - a.size);
  var longestSizeLabelLength = Math.max.apply(
    null,
    assets.map(a => stripAnsi(a.sizeLabel).length)
  );
  var suggestBundleSplitting = false;
  assets.forEach(asset => {
    var sizeLabel = asset.sizeLabel;
    var sizeLength = stripAnsi(sizeLabel).length;
    if (sizeLength < longestSizeLabelLength) {
      var rightPadding = ' '.repeat(longestSizeLabelLength - sizeLength);
      sizeLabel += rightPadding;
    }
    var isMainBundle = asset.name.indexOf('main.') === 0;
    var maxRecommendedSize = isMainBundle
      ? maxBundleGzipSize
      : maxChunkGzipSize;
    var isLarge = maxRecommendedSize && asset.size > maxRecommendedSize;
    if (isLarge && path.extname(asset.name) === '.js') {
      suggestBundleSplitting = true;