message: fix(package): fixed import failures in Webpack
  refactor: move re-export file mapping to bottom of mapping file
  Needed due to Webpack issue where sequence of the "alias" object keys matters:
diff: @@ -46,17 +46,18 @@ let rootPackageJson = Object.assign({}, pkg, {
  typings: './Rx.d.ts'
  });
  -// Create an object of key/value pairs resolving the "from" side
  -// of an import/require to the file name.
  -const importTargets = klawSync(CJS_ROOT, {
  +// Get a list of the file names
  +const fileNames = klawSync(CJS_ROOT, {
  nodir: true,
  filter: function(item) {
  return item.path.endsWith('.js');
  }
  })
  .map(item => item.path)
  -.map(path => path.slice((`${__dirname}/${CJS_ROOT}`).length))
  -.map(fileName => {
  +.map(path => path.slice((`${__dirname}/${CJS_ROOT}`).length));
  +
  +// Execute build optimizer transforms on ESM5 files
  +fileNames.map(fileName => {
  if (!bo) return fileName;
  let fullPath = path.resolve(__dirname, ESM5_ROOT, fileName);
  let content = fs.readFileSync(fullPath).toString();
  @@ -66,12 +67,21 @@ const importTargets = klawSync(CJS_ROOT, {
  });
  fs.writeFileSync(fullPath, transformed.content);
  return fileName;
  -})
  -.reduce((acc, fileName) => {
  +});
  +
  +// Create an object hash mapping imports to file names
  +const fileMappings = fileNames.reduce((acc, fileName) => {
  // Get the name of the file to be the new directory
  const directory = fileName.slice(0, fileName.length - 3);
  acc[directory] = fileName;
  + return acc;
  +}, {});
  +
  +// For node-resolved imports (rxjs/operators resolves to rxjs/operators/index.js), Webpack's "alias"
  +// functionality requires that the most broad mapping (rxjs/operators) be at the end of the alias
  +// mapping object. Created Webpack issue: https://github.com/webpack/webpack/issues/5870
  +const importTargets = Object.assign({}, fileMappings, fileNames.reduce((acc, fileName) => {
  // If the fileName is index.js (re-export file), create another entry
  // for the root of the export. Example:
  // fileName = 'rxjs/operators/index.js'
  @@ -81,7 +91,7 @@ const importTargets = klawSync(CJS_ROOT, {
  acc[fileName.slice(0, EXPORT_FILE.length + 1)] = fileName;
  }
  return acc;
  -}, {});
  +}, {}));
  createImportTargets(importTargets, "_esm5/", ESM5_PKG);
  createImportTargets(importTargets, "_esm2015/", ESM2015_PKG);
  