type inferrence with override methods in child class

[dislido]

Use Cases

interface TestProps {
  foo(num: number): number;
}
class Test extends React.Component<TestProps> {
  /**
   * sometimes we override functions and keep their parameters unchanged
   * in this case, the type of `nextProps` should be `Readonly<TestProps>` but inferred as `any`
   * we have to specify its type `nextProps: TestProps`
   * is there any way to tell typescript that we need to keep its parameters unchanged?
   * and typescript can find its type from the overridden function
   */
  componentWillReceiveProps(nextProps) {
    nextProps.foo(123);
  }
}

Examples

in parent classes

interface TestProps {
  foo(num: number): number;
}
namespace React {
  class Component<T> {
    /**
     * Any function that override it will inferred as (T) => void by default 
     */
    [some keywords?] componentWillReceiveProps(nextProps: T);
  }
}

in child classes

interface TestProps {
  foo(num: number): number;
}
class Test extends React.Component<TestProps> {

  /**
   * use (Readonly<P>) => void declared at React.Component
   */
  [some keywords?] componentWillReceiveProps(nextProps) {
    nextProps.foo(123);
  }
}

[jcalz]

Duplicate of #1373