RxJS v4 TestScheduler interface for RxJS v5


1221.0.34 years ago5 years agoMinified + gzip package size for @kwonoj/rxjs-testscheduler-compat in KB


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rxjs-testscheduler-compat provides RxJS v4's test scheduler interface to v5 version of RxJS allows to migrate existing test cases with minimum effort as well as writing new test cases for certain cases.


This has a peer dependencies of rxjs@5.*.*, which will have to be installed as well

npm install @kwonoj/rxjs-testscheduler-compat


You can import TestScheduler and other helpers to create test cases.

import * as Rx from 'rxjs';
import { TestScheduler, next, complete } from '@kwonoj/rxjs-testscheduler-compat';

const scheduler = new TestScheduler();
const observer = scheduler.createObserver();

const subject = scheduler.createHotObservable(
      next(20, 'a'),
      next(40, 'b'),
      next(60, 'c'),



As this does not patches anything in RxJS v5's test scheduler, you can use both if it's needed

import * as Rx from 'rxjs';
import { TestScheduler as CompatScheduler } from '@kwonoj/rxjs-testscheduler-compat';

const v5Scheduler = new Rx.TestScheduler(...);
const v4Scheduler = new CompatScheduler();


Migrating from RxJS v4 test scheduler

There are few changes in api surfaces to conform with v5's scheduler interface as well as enhance conviniences.

ReactiveTest helper functions

  • ReactiveTest.onNext(value) -> next(value)
  • ReactiveTest.onError(value) -> error(value)
  • ReactiveTest.onCompleted(value) -> complete(value)
  • ReactiveTest.subscribe(value) -> subscribe(value)

Notification factory method (next, error, complete) returns implementaiton of TestMessage and subscribe returns SubscriptionLog

Scheduler instance functions

  • TestScheduler::start() -> TestScheduler::flush()
  • does not support scheduler's instance methods for scheduling such as scheduleFuture, schedulerRecursive, schedulePeriodic... except scheduleAbsolute, scheduleRelative, startScheduler

Building / Testing

Few npm scripts are supported for build / test code.

  • build: Transpiles code to ES5 commonjs to dist.
  • build:clean: Clean up existing build
  • test: Run unit test. Does not require build before execute test.
  • test:cover: Run code coverage against test cases
  • lint: Run lint over all codebases
  • lint:staged: Run lint only for staged changes. This'll be executed automatically with precommit hook.
  • commit: Commit wizard to write commit message

If you find any bugs or have a feature request, please open an issue on github!

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