DraggableCore should be a PureComponent

[gajus]

Is there a reason why DraggableCore is not a PureComponent?

[STRML]

We don't want to make any assumptions about your application, but most importantly:

PureComponent is counterproductive with components that use children. this.props.children !== this.props.children, essentially always, unless the developer has made an effort to hoist the child. If they're doing that, they can hoist the <Draggable /> as well.

Making this a PureComponent would only introduce a shallowCompare() that will always fail.

[STRML]

See also facebook/react#8669.

[gajus]

Makes sense.