`defaultProps` rule to be deprecated on function components

defaultProps on function components is getting deprecated by React (see: https://github.com/facebook/react/pull/16210)

For this rule to follow suit, it should only be triggered when missing from class components.

The official recommendation in future versions of React is to use ES6 default values for function components.

[KevinGhadyani-minted]

The change isn’t to remove defaultProps from function components, but to use the official ES6 standard for defaulting props using object deconstruction and default assignment.

Where we once had:

const TestComponent.defaultProps = {
  size: 'medium',
  type: 'primary',
}

We now have:

const TestComponent = ({
  size = 'medium',
  type = 'primary',
}) => (
  // ...
)

The goal isn’t to remove defaultProps, but change how they’re defined on function components.

I would expect the defaultProps rules to function the same regardless of if I use defaultProps or object deconstruction and default assignment.

[ljharb]

Yes, it means someone would have to do the development work to add an option.

It makes sense to me to modify require-default-props so that the default is “defaultProps” for everything, but that there’s an option for function components to instead require “default arguments”, or, to ignore function components.