index.js

(function() {

  'use strict';

  function JasmineMatchers(files) {

    /**
     * @description
     * Add a new array item after the one at the supplied index.
     *
     * @param  {Array}  array
     * @param  {Number} index
     * @param  {*}      item
     */
    function insertAfter(array, index, item) {
      array.splice(index + 1, 0, item);
    }

    /**
     * @description
     * Is this file configuation the the "karma-jasmine" framework's jasmine library?
     *
     * @param  {Object}  file
     * @return {Boolean}
     */
    function isJasmine(file) {
      return file.pattern.search(/karma\-jasmine(\/|\\)lib(\/|\\)adapter\.js/) !== -1;
    }

    /**
     * @description
     * Get the array index of the "karma-jasmine" framework plugin in the files configuration.
     *
     * @param  {Object[]} files
     * @return {Number}
     */
    function indexOfJasmine(files) {
      for (var i = 0, len = files.length; i < len; i++) {
        if (isJasmine(files[i])) {
          return i;
        }
      }
      return -1;
    }

    /**
     * @description
     * Locate the Jasmine Utils library.
     *
     * @return {String}
     */
    function getLibPath() {
      return require.resolve('jasmine-utils');
    }

    // Init
    // ---------------------------------------------------------------------------------------------

    var ix = indexOfJasmine(files);

    if (ix !== -1) {
      insertAfter(files, ix, {
        pattern: getLibPath(),
        included: true,
        served: true,
        watched: false
      });
    } else {
      throw new Error('"jasmine" needs to appear before "jasmine-utils" in the "frameworks" array of your Karma configuration.');
    }

  }

  JasmineMatchers.$inject = ['config.files'];

  module.exports = {
    'framework:jasmine-utils': ['factory', JasmineMatchers]
  };

}());