chunk-manifest-webpack-plugin/lib/ChunkManifestPlugin.js

Allows exporting a manifest that maps chunk ids to their output files, instead of keeping the mapping inside the webpack bootstrap.

var RawSource = require("webpack-core/lib/RawSource");

function ChunkManifestPlugin(options) {
  options = options || {};
  this.manifestFilename = options.filename || "manifest.json";
  this.manifestVariable = options.manifestVariable || "webpackManifest";
  this.inlineManifest = options.inlineManifest || false;
}
module.exports = ChunkManifestPlugin;

ChunkManifestPlugin.prototype.constructor = ChunkManifestPlugin;
ChunkManifestPlugin.prototype.apply = function(compiler) {
  var manifestFilename = this.manifestFilename;
  var manifestVariable = this.manifestVariable;
  var inlineManifest = this.inlineManifest;
  var oldChunkFilename;
  var chunkManifest;

  compiler.plugin("this-compilation", function(compilation) {
    var mainTemplate = compilation.mainTemplate;
    mainTemplate.plugin("require-ensure", function(_, chunk, hash) {
      var filename = this.outputOptions.chunkFilename || this.outputOptions.filename;

      if (filename) {
        chunkManifest = [chunk].reduce(function registerChunk(manifest, c) {
          if(c.id in manifest) return manifest;
          var hasRuntime = typeof c.hasRuntime === 'function' ? c.hasRuntime() : c.entry;
          if(hasRuntime) {
            manifest[c.id] = undefined;
          } else {
            manifest[c.id] = mainTemplate.applyPluginsWaterfall("asset-path", filename, {
              hash: hash,
              chunk: c
            });
          }
          return c.chunks.reduce(registerChunk, manifest);
        }, {});
        oldChunkFilename = this.outputOptions.chunkFilename;
        this.outputOptions.chunkFilename = "__CHUNK_MANIFEST__";
        // mark as asset for emitting
        compilation.assets[manifestFilename] = new RawSource(JSON.stringify(chunkManifest));
        chunk.files.push(manifestFilename);
      }

      return _;
    });
  });

  compiler.plugin("compilation", function(compilation) {
    compilation.mainTemplate.plugin("require-ensure", function(_, chunk, hash, chunkIdVar) {
      if (oldChunkFilename) {
        this.outputOptions.chunkFilename = oldChunkFilename;
      }

      return _.replace("\"__CHUNK_MANIFEST__\"",
        "window[\"" + manifestVariable + "\"][" + chunkIdVar + "]");
    });

    if (inlineManifest){
      compilation.plugin("html-webpack-plugin-before-html-generation", function (data, callback) {
        var manifestHtml = "<script>window." + manifestVariable + "=" + JSON.stringify(chunkManifest) + "</script>";
        callback(null, data.assets[manifestVariable] = manifestHtml);
      });
    }
  });
};