Testing polling in Ember

acceptance-test.js

module('Acceptance | Rooms', () => {
  test('Room page polls for room data', async function(assert) {
    assert.expect(2);

    let pollingServiceMock = {
      start(fetchingTaskInstance, pollingFrequency) {
        assert.ok(fetchingTaskInstance, 'Polling started for rooms');
        assert.equal(pollingFrequency, 5000, 'Poll every 5 seconds');
      }
    };

    this.owner.register('service:polling-service', pollingServiceMock);

    await visit('/rooms/1')
  });

  test('Room page stops polling when you leave the page', async function(assert) {
    assert.expect(2);

    let pollingServiceMock = {
      start() {
        assert.ok(true, 'Polling started');
      }
      stop() {
        assert.ok(true, 'Polling stopped');
      }
    };

    this.owner.register('service:polling-service', pollingServiceMock);

    await visit('/rooms/1')
    await click('[data-test-menu-entries]');
  });
});

polling-service.js

class pollingService {
  constructor() {
    this.isPolling = false;
  }

  start(thingWeWantToPoll, pollingFrequency) {
    this.isPolling = true;
    while (this.isPolling) {
      yield thingWeWantToPoll();
      yield timeout(pollingFrequency);
    }
  }

  stop() {
    this.isPolling = false;
  }
}

route.js

class RoomRoute {
  pollingService: service(),

  activate() {
    pollingService.start(this.fetchRooms.perform(), 5000);
  }

  deactivate() {
    pollingService.stop();
  }
}

unit-test.js

module('Unit | Polling Service', () => {
  test('Polling service starts a task', async function(assert) {
    assert.expect(2);

    let functionToPoll = () => {
      assert.ok(true, 'function called');
    };

    let pollingService = this.owner.lookup('service:metrics');

    pollingService.start(functionToPoll, 0);

    expect.ok(pollingService.isPolling);
  });

  test('Polling service stops a task', async function(assert) {
    assert.expect(1);

    let pollingService = this.owner.lookup('service:metrics');

    pollingService.stop();

    expect.notOk(pollingService.isPolling);
  });
});