articles.001.005.component-type-assert.tsx

// Approach 1: the easy way out
// 
// We can just define the return type of our Select
// and make sure it matches the return type of React.FC
function Select<T>(props: SelectProps<T>): React.ReactElement | null {
  return null;
}

// Approach 2: diving back in looking for a better way
// 
// We can create a type that accepts a type parameter
// and puts a constraint on it, in our case we will demand
// the type parameter to be a React.FC
type AssertComponent<C extends React.FC<any>> = C;

// Then we use it in our Select component
type AssertSelect = AssertComponent<typeof Select>;

// Approach 3: the light at the end of the tunnel
// 
// TypeScript 3.7 introduced "assertion signatures" that
// allow us to define an assertion function. 
// We might use such function to ensure that anything we pass to it is a React.FC 
// while writing no code whatsoever! BINGO!
function assertFC<P>(component: React.FC<P>): asserts component is React.FC<P> {}

// Then in your Select component
assertFC(Select);