Mailspring/app/spec/models/query-subscription-pool-spec.es6

import QuerySubscriptionPool from '../../src/flux/models/query-subscription-pool';
import DatabaseStore from '../../src/flux/stores/database-store';
import Label from '../../src/flux/models/label';

describe('QuerySubscriptionPool', function QuerySubscriptionPoolSpecs() {
  beforeEach(() => {
    this.query = DatabaseStore.findAll(Label);
    this.queryKey = this.query.sql();
    QuerySubscriptionPool._subscriptions = {};
    QuerySubscriptionPool._cleanupChecks = [];
  });

  describe('add', () => {
    it('should add a new subscription with the callback', () => {
      const callback = jasmine.createSpy('callback');
      QuerySubscriptionPool.add(this.query, callback);
      expect(QuerySubscriptionPool._subscriptions[this.queryKey]).toBeDefined();

      const subscription = QuerySubscriptionPool._subscriptions[this.queryKey];
      expect(subscription.hasCallback(callback)).toBe(true);
    });

    it('should yield database changes to the subscription', () => {
      const callback = jasmine.createSpy('callback');
      QuerySubscriptionPool.add(this.query, callback);
      const subscription = QuerySubscriptionPool._subscriptions[this.queryKey];
      spyOn(subscription, 'applyChangeRecord');

      const record = { objectType: 'whateves' };
      QuerySubscriptionPool._onChange(record);
      expect(subscription.applyChangeRecord).toHaveBeenCalledWith(record);
    });

    describe('unsubscribe', () => {
      it('should return an unsubscribe method', () => {
        expect(QuerySubscriptionPool.add(this.query, () => {}) instanceof Function).toBe(true);
      });

      it('should remove the callback from the subscription', () => {
        const cb = () => {};

        const unsub = QuerySubscriptionPool.add(this.query, cb);
        const subscription = QuerySubscriptionPool._subscriptions[this.queryKey];

        expect(subscription.hasCallback(cb)).toBe(true);
        unsub();
        expect(subscription.hasCallback(cb)).toBe(false);
      });

      it("should wait before removing th subscription to make sure it's not reused", () => {
        const unsub = QuerySubscriptionPool.add(this.query, () => {});
        expect(QuerySubscriptionPool._subscriptions[this.queryKey]).toBeDefined();
        unsub();
        expect(QuerySubscriptionPool._subscriptions[this.queryKey]).toBeDefined();
        advanceClock();
        expect(QuerySubscriptionPool._subscriptions[this.queryKey]).toBeUndefined();
      });
    });
  });
});