Defining DefaultProps with HOC

defaultProps.d.ts

import React from 'react';

const withTheme = <P extends {}>(Comp: React.ComponentType<P>) => {
    return Comp as any as React.ForwardRefExoticComponent<
        React.PropsWithoutRef<P> &
            React.RefAttributes<any>
    > & {
        defaultProps: typeof Comp['defaultProps'];
    };
}

class Button extends React.Component<{size: string }> {
    static defaultProps = {
        size: 'l'
    }
}

const ThemedButton = withTheme(Button)
ThemedButton.defaultProps = Button.defaultProps;

const a = () => <Button />
const b = () => <ThemedButton />

https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBAJQKYEMDG8BmUIjgcilQ3wG4AoctCAOwGd4B3YGACwBVWkQk4BeOAB4ACnCQAPGEhoATOnADeAXwB8ACgDCuMAC5ExGADot4WtJjsAnmCQiVASn4rF5OG7hEYAVyg04JsDgUeRQaSyD5ZHQjADFoRhQoGWRMAFFxCBhgNACzGhhBV3diqIxDYRwwOgB1FlYILxgUuzgAMiLizv1owxSAQRgYKGAAI0akOkFQyxUOuGdWly63GSRMFC8AGxgKiCq9GGskCEx-bQBtfFX1rZ3KunwAXQpipQolSjRN4PkAIUaYLQxJJpHJumVcjRzIIFHRgAAvJB6BjDGgAczgqiW7gYKCyaDg1w2212VX42K6cMRenwm3wcw+HyotAYcE43CQMn+gyBAmYbHZPDU3MBNHs5EFnJFtEMRNupPkAmlNFla2Jdz2dAozPo8BQ5LUjj4zkEyrgAHpZtRdXARgajSbJVyAUDLUA