is-prototype-of-x v2.1.2

is-prototype-of-x

Checks if an object exists in another object's prototype chain.

module.exports(proto, object) ⇒ boolean ⏏

This method checks if an object exists in another object's prototype chain.

Kind: Exported function
Returns: boolean - Does the proto object lay in the prototype chain of object.
Throws:

• TypeError If proto is undefined or null.

Example

import isPrototypeOf from 'is-prototype-of-x';

function Foo() {}
function Bar() {}
function Baz() {}

Bar.prototype = Object.create(Foo.prototype);
Baz.prototype = Object.create(Bar.prototype);

const baz = new Baz();

console.log(isPrototypeOf(Baz.prototype, baz)); // true
console.log(isPrototypeOf(Bar.prototype, baz)); // true
console.log(isPrototypeOf(Foo.prototype, baz)); // true
console.log(isPrototypeOf(Object.prototype, baz)); // true