articles.001.005.component-type-approach-3.tsx

// Approach 3: the light at the end of the tunnel
// 
// TypeScript 3.7 introduced "assertion functions" 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> {
  // We don't need to do anything here because the assertion happens
  // on the type level - we need to pass a valid React component
}

// Then we use it in our Select component
function Select<T>(props: SelectProps<T>): React.ReactElement | null {
  return null;
}
  
assertFC(Select);