CODEWITHSUNDEEP
angularangular7ngrx-effectsjasmine-marbles
Anand
Anand

Reputation: 245

Ngrx Effects spec throws Error as "No test scheduler initialized"

Trying to run a simple effects test with an existing and recently migrated Angular 7 project. But I get error as below.

Error: No test scheduler initialized at getTestScheduler (node_modules/jasmine-marbles/es6/src/scheduler.js:11:1) at new TestHotObservable (node_modules/jasmine-marbles/es6/src/test-observables.js:21:39) at Module.hot (node_modules/jasmine-marbles/es6/index.js:7:1)

My code in effects spec file is basic standard check with jasmine-marbles.

const action = new Load(request);
const completion = new LoadSuccess(result);

actions$ = hot('-a-', { a: action});
const response = cold('-a|', {a: result});
const expected = cold('--b', {b: completion});
service.getSomething.and.returnValue(result);
expect(effects.load$).toBeObservable(expected);

Has anyone seen and resolved this error before?

Upvotes: 3

Views: 3434

Answers (4)

Eneko
Eneko

Reputation: 2117

In my case the reason for the No test scheduler initialized error was using cold outside the beforeEach block.

Creating the test observables inside the beforeEach block solved the problem.

Upvotes: 1

andrewpm
andrewpm

Reputation: 564

Upgrading jasmine-marbles to 0.6.0 resolved this problem for me.

Upvotes: 7

Anand
Anand

Reputation: 245

Although changing to ES5 fixed the problem, my colleague has come up with a better solution. Solution is to add the following lines in src/test.ts file. I like it better as it allows to continue testing in ES6.

import { addMatchers, getTestScheduler, initTestScheduler, resetTestScheduler } from 'jasmine-marbles';

// configure matchers for jasmine-marbles
jasmine.getEnv().beforeAll(() => {
  return addMatchers();
});
jasmine.getEnv().beforeEach(() => {
 initTestScheduler();
});
jasmine.getEnv().afterEach(() => {
 getTestScheduler().flush();
 resetTestScheduler();
});

Upvotes: 9

Anand
Anand

Reputation: 245

After further research figured out that it was due to compiler options in tsconfig.spec.json. Originally it was setup as "target": "es6", changing it to es5 fixed this issue and specs are successfully running now.

Upvotes: 0

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