Rxjs5 test compare

rx-collection-compare.js

const assert = require('chai').assert;

/**
 * parts of code taken from https://github.com/Reactive-Extensions/RxJS/blob/master/tests/helpers/reactiveassert.js#L32
 *
 * and modified to work with the rxjs5 testing shim which has no differentiation between values and predicates
 */
exports.assertEqual = function assertEqual(actual, expected) {
  const comparer = require('./is-equal'); // copied and adapted from https://raw.githubusercontent.com/Reactive-Extensions/RxJS/master/src/core/internal/isequal.js
  let isOk = true;

  if (expected.length !== actual.length) {
    return assert.fail(expected.length, actual.length, `Not equal length. Expected: ${expected.length} actual:${actual.length}`);
  }

  for (let i = 0, len = expected.length; i < len; i++) {
    const e = expected[i], a = actual[i];

    // if the value is a function then use it as assertion instead of equality comparison
    let compareDelegate = null;
    if (e.notification.value && typeof e.notification.value === 'function') {
      compareDelegate = e.notification.value;
    } else if (e.notification.error && typeof e.notification.error === 'function') {
      compareDelegate = e.notification.error;
    }

    if (compareDelegate !== null) {
      isOk = e.frame === a.frame && e.notification.kind === a.notification.kind;
      if (!isOk) {
        return assert.fail(expected[i], actual[i], `Emission ${1 + i}@${a.time} did not match timing or kind of expected emission. Expected ${e.notification.kind}@${e.frame} \n\n Emission not matching: \n\n ${JSON.stringify(a.notification.value, jsonSerialiserRemoveSchedulers, ' ')}`);
      }

      isOk = compareDelegate(a.notification);
      if (!isOk) {
        return assert.fail(expected[i], actual[i], `Emission ${1 + i}@${a.time} did not match predicate for emission @${e.time}. \n Predicate: \n\n${e.notification.value} \n\n Emission not matching: \n\n ${JSON.stringify(a.notification.value, jsonSerialiserRemoveSchedulers, ' ')}`);
      }
    } else {
      isOk = comparer(e, a);
      if (!isOk) {
        return assert.fail(e, a, `Emission ${1 + i} not as expected. \n Expected: \n\n${JSON.stringify(e, jsonSerialiserRemoveSchedulers, ' ')} \n\n But got: \n\n ${JSON.stringify(a, jsonSerialiserRemoveSchedulers, ' ')}`);
      }
    }
  }
};

function jsonSerialiserRemoveSchedulers(key, value) {
  // Filtering out properties of schedulers to make the assertions more readable
  if (key != null && key.startsWith('_') || key === 'scheduler') {
    return undefined;
  }
  return value;
}

usage.js

const rxStreamCompareUtils = require('./rx-collection-compare');
const TestScheduler = require('@kwonoj/rxjs-testscheduler-compat').TestScheduler;
const next = require('@kwonoj/rxjs-testscheduler-compat').next;

describe('example-test', () => {
  it('compares using a predicate', () => {
    const scheduler = new TestScheduler();
    
    const results = scheduler.startScheduler(
      () => Rx.Observable.just({foo: { bar: 1234 }}).delay(100, scheduler)
    );
    
    rxStreamCompareUtils.assertEquals(results.messages, [
      next(200, evt => evt.value && evt.value.foo.bar === 1234)
    ]);
  });
});

note; the ./is-equal.js file is absent in this gist; it is a 99.9% copy from https://raw.githubusercontent.com/Reactive-Extensions/RxJS/master/src/core/internal/isequal.js only fixing references and exporting the complete file as module.exports = isEqual;