Don't fire the observer if the result of a query hasn't changed

[Poincare]

If we have a watchQuery observer and we receive a result from the server that is identical to the last result we handed to the observer, we should not call the observer at all. This will prevent solutions like using shouldComponentUpdate and will reduce useless re-renders on the page.

[nevir]

I'm unsure if I'm running into the same thing, or a variation on it:

I have a watchQuery (with noFetch: true) - the observer's next fires 2 or 3 times each time the store is changed, even if some other portion of the store (not owned by apollo) was modified

[Poincare]

@nevir Hm. That should not happen if the part of the store associated with the store was left untouched. Could you file an issue that would allow us to reproduce the problem? (a unit test would also be great!)

[Poincare]

Since #402 was merged, this issue can now be closed.

[stubailo]

And deployed!

[stubailo]

@nevir can you check if 0.4.2 fixes your issue with multiple firing?

[nevir]

@stubailo can confirm - all better as of 0.4.2

[stubailo]

Sweet! It really helped in our app as well.