directiv-core-builder/lib/loaders-by-extension.js

module.exports = function loadersByExtension(obj) {
  var loaders = [];
  var extensions = Object.keys(obj).map(function(key) {
    return key.split("|");
  }).reduce(function(arr, a) {
    arr.push.apply(arr, a);
    return arr;
  }, []);
  Object.keys(obj).forEach(function(key) {
    var exts = key.split("|");
    var value = obj[key];
    var entry = {
      extensions: exts,
      test: extsToRegExp(exts),
      loaders: value
    };
    if(Array.isArray(value)) {
      entry.loaders = value;
    } else if(typeof value === "string") {
      entry.loader = value;
    } else {
      Object.keys(value).forEach(function(key) {
	entry[key] = value[key];
      });
    }
    loaders.push(entry);
  });
  return loaders;
};

function extsToRegExp(exts) {
  return new RegExp("\\.(" + exts.map(function(ext) {
    return ext.replace(/\./g, "\\.") + "(\\?.*)?";
  }).join("|") + ")$");
}