observable-filter-observable.js

test('filter stream of data points based on selected tags', function () {
  // Model the user selecting new tags in the UI. A new tag is selected
  // each 100 time units.
  var selectedTags = this.scheduler.createHotObservable(
    onNext(210, ['tag-001']),
    onNext(310, ['tag-001', 'tag-002']),
    onNext(410, ['tag-001', 'tag-002', 'tag-003']),
    onCompleted(420)
  );

  var dataPoints = this.scheduler.createHotObservable(
    onNext(200, { name: 'tag-001' }),
    onNext(210, { name: 'tag-002' }),
    onNext(220, { name: 'tag-003' }),
    onNext(230, { name: 'tag-001' }),
    onNext(240, { name: 'tag-002' }),
    onNext(250, { name: 'tag-003' }),

    onNext(310, { name: 'tag-001' }),
    onNext(320, { name: 'tag-002' }),
    onNext(330, { name: 'tag-003' }),
    onNext(340, { name: 'tag-001' }),
    onNext(350, { name: 'tag-002' }),
    onNext(360, { name: 'tag-003' }),

    onNext(410, { name: 'tag-001' }),
    onNext(420, { name: 'tag-002' }),
    onNext(430, { name: 'tag-003' }),
    onNext(440, { name: 'tag-001' }),
    onNext(450, { name: 'tag-002' }),
    onNext(460, { name: 'tag-003' }),
    onCompleted(470)
  );

  var results = this.scheduler.startWithCreate(function () {
    return selectedTags
      .map(function (tags) {
        return dataPoints.filter(function (d) {
          return tags.indexOf(d.name) > -1;
        });
      })
      .switchLatest()
      .map(function (d) {
        return d.name;
      });
  });

  var expectedMessages = [
    onNext(230, 'tag-001'),
    onNext(310, 'tag-001'),
    onNext(320, 'tag-002'),
    onNext(340, 'tag-001'),
    onNext(350, 'tag-002'),
    onNext(410, 'tag-001'),
    onNext(420, 'tag-002'),
    onNext(430, 'tag-003'),
    onNext(440, 'tag-001'),
    onNext(450, 'tag-002'),
    onNext(460, 'tag-003'),
    onCompleted(470)
  ];

  assertEqual(expectedMessages, results.messages);
});