Check if a constructor inherits another in ES6

Question

I have a situation where I need to check if a constructor (X) has another constructor (Y) in its prototype chain (or is Y itself).

The quickest means to do this migh

Answer 1

There's also Object.prototype.isPrototypeOf(). Seems like a perfect use case, no?

Babel

class A {}
class B extends A {}
class C extends B {}
console.log(C === C)
console.log(B.isPrototypeOf(C))
console.log(A.isPrototypeOf(C))