acii-marbles.md

Confusing

• ( and ) count as frame

describe('`(` and `)`', () =>  {
  let testScheduler: TestScheduler;

  beforeEach(() => {
    testScheduler = new TestScheduler(observableMatcher);
  });

 
  describe.only('`(` and `)`', () =>  {
    let testScheduler: TestScheduler;

    beforeEach(() => {
      testScheduler = new TestScheduler(observableMatcher);
    });

    it('should take one frame for `(` and one frame for `)`', () =>  {
      testScheduler.run(({cold, hot, expectObservable}) => {
        const a = cold('---------------|');
        const a1 =     '-()------------|';
        const b = cold('----1----------|');
        const b1 =     '-()-(1)--------|';
        const b2 =     '-()-(1)--()----|';
        const c = cold('----1----(23)--|');
        const c1 =     '-()-(1)()(23)--|';
        const c2 =     '-()-(1)()(23)--|';
        const c3 =     '-()-(1)()(23)()|';
        expectObservable(a).toBe(a1);
        expectObservable(b).toBe(b1);
        expectObservable(b).toBe(b2);
        expectObservable(c).toBe(c1);
        expectObservable(c).toBe(c2);
        expectObservable(c).toBe(c3);
      });
    });
  });

• ^ only exists in hot observables

describe.only('`^`', () =>  {
    let testScheduler: TestScheduler;

    beforeEach(() => {
      testScheduler = new TestScheduler(observableMatcher);
    });
    it('should take one frame', () => {
      const a = cold('-1---|');
      const a1 =     '-1---|';
      const aSubs =  [
                     '^----!'
      ];
      const ar = a.pipe(tap());
      expectObservable(ar).toBe(a1);
      expectSubscriptions(a.subscriptions).toBe(aSubs);
    });
    it('should exist only on hot observables and outputs ans subscriptions', () =>  {
      testScheduler.run(({hot, expectObservable}) => {
        const a = hot('^1----------|');
        const a1 =    '^1----------|';
        const aSubs = '^-----------!';
        const ar = a.pipe(tap());
        expectObservable(ar).toBe(a1);
        expectSubscriptions(a.subscriptions).toBe(aSubs);
      });
    });
  });

• is ignored in cold and hot observables due to time progression syntax, but considered as frame in subscriptions

Guide lines

0 index usage

The zero index exists only in hot observables and can be specified by using ^. If not specified it exists implizitly at the beginning of an hot observable.

hot('----|') === hot(' ----|') === hot('^---|') === hot(' ^---|')
hot('-^---|') === hot('-^---|') :D

0 index alignment

// Old style ==================
import { hot, cold, expectObservable, expectSubscriptions } from '../helpers/marble-testing';

const s1 = hot('-^-x------------------|');
const s1Subs =  '^                    !';
const n1 = cold('  ------------------------|');
const n1Subs = ['  ^                  !'];
const exp =     '--x------------------|';

// New style ==================
import {TestScheduler} from 'rxjs/internal/testing/TestScheduler';

const testScheduler = new TestScheduler(observableMatcher);

testScheduler.run(({cold, hot, expectObservable, expectSubscriptions}) => {
  const s1 =  hot('-^-x------------------|  ');
  const s1Subs =  '^--------------------!   ';
  const n1 = cold('------------------------|');
  const n1Subs = ['--^------------------!   '];
  const exp =     '--x------------------|   ';

// New style proper 0 index alignment ==================
import {TestScheduler} from 'rxjs/internal/testing/TestScheduler';

const testScheduler = new TestScheduler(observableMatcher);

testScheduler.run(({cold, hot, expectObservable, expectSubscriptions}) => {
  const s1 =  hot('-^-x------------------|     ');
  const s1Subs =  ' ^--------------------!     ';
  const n1 = cold('   ------------------------|');
  const n1Subs = [' --^------------------!     '];
  const exp =     ' --x------------------|     ';
})