Throw error when stores are chained in a circular loop

[spoike]

Story

As a developer using reflux
When I accidentally chain stores in a circular loop
Reflux.listenTo should throw an error notifying of the circular dependecy

Do some listener dependency tracking on actions and stores to make sure that developers don't accidentally do circular dependency and have an indication where it went wrong.

[dashed]

Maybe have set of recipients that received the emit request have been passed to? The first store that receives an emit will create and sign the recipient set with its own instance and then pass onto the next store. If a store finds its 'signature' (instance) on the recipient set, then there's an illegal cycle.

[dashed]

Instead of a store's instance, have an integer id. createStore would just assign and increment an integer id for every new store.

[spoike]

Sounds like you have a plan @dashed 👍 ;-)

[spoike]

The test is basically testing that you can't chain two stores in a circular loop and also that you can't chain the store with itself (which is the tiniest loop possible). Sample:

// throwingErrorDuringCircularLoop.spec.js or something
describe('when a store is created', function() {
    var store1;

    beforeEach(function() {
        store1 = Reflux.createStore({});
    });

    it('should fail when it listens to itself', function() {
        store1.listenTo(store1, _.noop);
        // assert that error is thrown, which I don't remember at the moment
        // how you do it in chai
    });

    describe('and another store is created', function() {
        var store2;

        beforeEach(function() {
            store2 = Reflux.createStore({});
        });

        it('should fail when both listen to each other', function() {
            store1.listenTo(store2, _.noop);
            store2.listenTo(store1, _.noop);
            // assert that error is thrown
        });

    });
});

[spoike]

I'm adding this feature for 0.1.6 milestone, together with #27 and #28, so Reflux will be in feature parity with facebook/flux

[spoike]

Let me know if you want to take this one @dashed. If not I'll probably jump on it when I have the time in the weekend.

[dashed]

@spoike You can take this one. I won't have time to look at it till next week Tuesday.

[spoike]

Been too busy with IRL stuff this weekend so I haven't had the time to look into this. Anyone is free to take a gander at it... if nobody does then I'll notify if I start working on this.

[spoike]

I have a solution now. Need to integrate with Reflux.all in #28 and it'll be done.