Make default initial state of a component `{}`

[macalinao]

I find myself writing getInitialState: function() { return {}; } way too often. A lot of components wait for AJAX requests before setting any state variables, and doing this will make things much easier.

[gaearon]

I usually set these variables to null in this cases. Also serves as a kind of documentation.

I think React is trying to save some allocations here although not sure!

[syranide]

I'm going to 👍 @gaearon on this, explicitly setting the allowed state properties to null is good documentation and also an optimization (or two actually, reduce allocations and shadow classes). There has also been some mention (just mention) of only allowing to set state properties that exist, else throwing, which I think sounds like a really great idea and another reason why you would want it to be explicit.

[gaearon]

There has also been some mention (just mention) of only allowing to set state properties that exist, else throwing, which I think sounds like a really great idea and another reason why you would want it to be explicit.

I'd love if that was the case btw

[syranide]

@gaearon Speaking of the devil... #2805 (comment)

The idea is to make state a record-like object with fixed keys. E.g. you should specify all keys in the initial state and never add extra keys. It ensures type stability both for type systems and VMs. It also ensures that you explicitly define an initial and descriptive value.

[sophiebits]

Yeah – if anything, we're going to warn when you add new properties to state that getInitialState didn't return.