Subset and computed properties first computation order

[samuelsimoes]

Today, the subsets are computed on the store construction after the computed properties first compution. This works for most of cases, but you could get on this kind of situation:

class Todos extends Fluxo.CollectionStore {
  pendingCount () {
    return this.subsets.pending.stores.length;
  }

  pending () {
    return this.where({ done: false });
  }
};

Todos.computed = {
  pendingCount: ["change:pending"]
};

Todos.subset = {
  pending: ["stores:change:done"]
};

var todos = new Todos([{ done: false }, { done: true }]);

todos.data.pendingCount // 0;

We can easily fix this computing subsets first on the construction, but Isn't hard imagine situations where subset can depend on some computed property.

I think we need a way to compute every computed property and subset on first object construction computing the dependencies first.

I already tried something, but it doesn't look a simple task to get this with elegant code.

[samuelsimoes]

Like discussed on chat, let first fix this with a more simple approach, computing subsets before computed properties (https://github.com/fluxo-js/fluxo/commit/f2c7c8aface54906c58f5cf5b5b845a786ca874f), if this kind of dependency managment turns into a necessary thing, we reconsiders.

[samuelsimoes]

I just have an epiphany moment to fix this issue, not that I had this problem recently but I really think the Fluxo's first computation on store construction is inconsistent with what happen on the subsequent state mutations, so I thought on a little tweak that could address this issue.

The basically idea is:

1. Start a wildcard listener to collect all events.
2. Do the Fluxo.ObjectStore#set on the constructor.
3. Do the Fluxo.CollectionStore#setStores on the constructor (if it's a collection).
4. Register the computed and subsets.
5. Retrigger all events collected by the listener on the first step and everything will work on the chosen order by the dependent events.

Take a look in the branch https://github.com/fluxo-js/fluxo/compare/smart-first-computation.

What do you think?