Create annotation that allows you to mutate observable members directly

[ghsolomon]

If possible- create an annotation that overrides the Javascript setter for a member and wraps it with runInAction so developers can write code like this:

@mutatable myProperty; // Makes myProperty observable and wraps the JS setter with `runInAction`
myProperty = newValue // "Under the hood", executes: `runInAction(() => myProperty = newValue)`

[lbwexler]

Hi @ghsolomon

So a really fascinating discussion about this in the mobx community from 2017. Mwestrate proposese something called @box.

mobxjs/mobx#839
(its a very long thread, but worth reading through to the end)

Makes me think:

a) do we really need to be using strict mode? What is it really getting us?
b) If we do continue to use strict mode we should probably introduce this.

The name you mention is interesting, and seems more intuitive (to me) then @box. I wish that we had not already used up "bindable"!

[lbwexler]

I think the @mutable term implies that without it, somehow the data is immutable (which is definitely not the case).

I would probably lean toward just enhancing @bindable so that it continues to create a setter, but also creates a set method. The only problem there would be with existing uses that are overriding the setter that @bindable creates. That seems like a weird usage, but definitely one we have supported.

[lbwexler]

As to what "strict/enforceActions" mode is getting us -- I really think it just comes down to a fairly coarse way of ensuring that applications use @action wherever possible to generate transactions and avoid extra re-rendering/reactions. I guess the fear is that if you don't require it people won't use it at all!