compilation-addEntry.js

compilation-addEntry.js

/**
 * @param {string} context context path for entry
 * @param {Dependency} entry entry dependency that should be followed
 * @param {string | EntryOptions} optionsOrName options or deprecated name of entry
 * @param {ModuleCallback} callback callback function
 * @returns {void} returns
 */
addEntry(context, entry, optionsOrName, callback) {
  // TODO webpack 6 remove
  const options =
    typeof optionsOrName === "object" ? optionsOrName : { name: optionsOrName };

  this._addEntryItem(context, entry, "dependencies", options, callback);
}

/**
 * @param {string} context context path for entry
 * @param {Dependency} entry entry dependency that should be followed
 * @param {"dependencies" | "includeDependencies"} target type of entry
 * @param {EntryOptions} options options
 * @param {ModuleCallback} callback callback function
 * @returns {void} returns
 */
_addEntryItem(context, entry, target, options, callback) {
  //'name' should just be set to the default 'main' since
  //we passed in an empty options object to the top-level 'webpack'
  const { name } = options;

  let entryData =
    name !== undefined ? this.entries.get(name) : this.globalEntry;

  if (entryData === undefined) {
    //We fall into this case where we have to construct our own entryData
    entryData = {
      dependencies: [],
      includeDependencies: [],
      options: {
        name: undefined,
        ...options,
      },
    };
    //I'm not quite sure how entryData will be used later on but at
    //least we know it has the original 'entry' parameter in 'dependencies'
    entryData[target].push(entry);
    this.entries.set(name, entryData);
  } else {
    /*****
        I deleted what was in this 'else' since we're only 
        focused on our example of single file bundling for now
        ******/
  }

  //I don't think this hook is used by the core webpack
  //library so let's ignore it for now and re-visit it later on
  this.hooks.addEntry.call(entry, options);

  //If you look closely this call only needs the 'context',
  //'entry', and 'callback' parameter values to move on (dropping the 'options').
  //I wonder how the 'this.entries' populated above is used further in the pipeline
  this.addModuleChain(context, entry, (err, module) => {
    if (err) {
      this.hooks.failedEntry.call(entry, options, err);
      return callback(err);
    }
    this.hooks.succeedEntry.call(entry, options, module);
    return callback(null, module);
  });
}