`react/require-default-props` shows error despite default prop value defined - why?

Question

This question is about the rule require-default-props.

Here's my code:

function MyComponent({
  blubb = 'my default',
}: {
  blubb?: string,
}) {
  // blubb is 'my default' by default
};

Eslint complains that MyComponent.defaultProps is not configured correctly.

In fact I didn't set it up because the default is already part of the function signature. (which works)

Question 1: Why does eslint-plugin-react require defaults to be set under defaultProps and not the way I defined it above?

Question 2: Why is this rule even enabled by default? Isn't the purpose of optional parameters TO BE OPTIONAL? What if my default value is simply... undefined? Why do I have to define a default value of undefined when the default is already undefined?

Thank you in advance. <)

Answer 1

You can set up a rule in eslintrc.js according to the documentation

Add the following code to the rules section

'react/require-default-props': [2, {
  functions: 'defaultArguments',
}],