Understanding why super() is deprecated in a React class component

It looks like the optional context parameter is deprecated because it refers to the legacy React context (pre v16.3). What version of React are you using?

https://reactjs.org/docs/legacy-context.html

I have not used React with TypeScript. Maybe React mappings are out of date.

You need super(props); only if you gonna use this.props in the constructor. Otherwise you can use super(); If you use super(); in the constructor it is not a problem that outside of the constructor you will call this.props. You can read about it in the following link: https://overreacted.io/why-do-we-write-super-props/

class Button extends React.Component {
  constructor(props) {
    super(); //we forgot to pass props
    console.log(props); //{}
    console.log(this.props); //undefined
  }
  // ...
}

It can be even more challenging if this happens in some method that's called from the constructor. And that's why I recommend always passing down super(props), even through it isn't necessary.

class Button extends React.Component {
  constructor(props) {
    super(props); //we passed props
    console.log(props); //{}
    console.log(this.props); //{}
  }
  // ...
}

super(props); isn't deprecated yet. The deprecation message actually caused from a bug in React's type definition file and is already fixed as of @types/react 16.9.51. Just upgrade the package and you're good to go:

npm install @types/react