Revision history [back]

The process for testing an infinite stream using Jasmine Marbles has several steps:

1. First, import the necessary modules into your test file:

import { TestScheduler } from 'rxjs/testing';
import { cold } from 'jasmine-marbles';

1. Create a new instance of the TestScheduler class:

const scheduler = new TestScheduler((actual, expected) => {
  expect(actual).toEqual(expected);
});

1. Define your input stream using the cold function from jasmine-marbles. This function takes a string as its argument, representing the values emitted by the stream over time. For example:

const input = cold('a-b-c-d-|');

1. Define your expected output stream using a similar cold function:

const expectedOutput = cold('a-b-c-d-|');

1. Subscribe to your input stream and expect it to equal your expected output using the expectObservable function:

scheduler.expectObservable(input).toBe(expectedOutput);

1. Finally, flush the test scheduler to execute the test:

scheduler.flush();

This will test whether the input stream emits the expected values at the expected times.