RxJS JestJS / Jasmine2 Custom Matcher

customMatcher.js

/* * *
 * Just a quick tester to help with Rx testing...
 * - - -
 * Be sure to include in the jest config...
 * "setupTestFrameworkScriptFile": "<rootDir>/{pathTo}/customMatchers.js",
 * "testRunner": "<rootDir>/../node_modules/jest-cli/src/testRunners/jasmine/jasmine2.js"
 * - - -
 * Usage...should be something similar to what is below (untested)
 *
 * const subject = new Rx.Subject();
 * const scheduler = new Rx.TestScheduler();
 * const onNext = Rx.ReactiveTest.onNext;
 *
 * results = scheduler.startScheduler(() => {
 *   return subject.asObserver();
 * });
 * 
 * scheduler.scheduleAbsolute({}, 300, () => {
 *   subject.onNext({topic: 'helloWorld'});
 * });
 *
 * expect(results.messages).toHaveEqualElements(onNext(300, {topic: 'helloWorld'}), ...onNext({})) // If you have more...
 * * */

'use strict';

function areElementsEqual(actual, expected, comparer) {
  var Rx = require('rx');
  var theComparer = comparer || Rx.internals.isEqual;

  if (expected.length !== actual.length) {
    return false;
  }

  for (var id = 0; id < expected.length; id++) {
    if (!theComparer(expected[id], actual[id])) {
      return false;
    }
  }
  
  return true;
}

var customMatchers = {
  toHaveEqualElements: function(util, customEqualityTesters) {
    return {
      compare: function(actual, expected) {
        var len = arguments.length;
        var expecteded = new Array(len-1);

        for (var id = 1; id < len; id++) {
          expecteded[id-1] = arguments[id];
        }

        return { pass: areElementsEqual(actual, expecteded) };
      }
    };
  }
}

jasmine.getEnv().beforeEach(function() {
  jasmine.addMatchers(customMatchers);
});