src/tests/testinstof.js

/* eslint-disable no-self-compare */
/**
 * 
 *  ██▓ ███▄    █  ██ ▄█▀     ██████  ██▓███   ██▓    ▄▄▄     ▄▄▄█████▓
 *  ▓██▒ ██ ▀█   █  ██▄█▒    ▒██    ▒ ▓██░  ██▒▓██▒   ▒████▄   ▓  ██▒ ▓▒
 *  ▒██▒▓██  ▀█ ██▒▓███▄░    ░ ▓██▄   ▓██░ ██▓▒▒██░   ▒██  ▀█▄ ▒ ▓██░ ▒░
 *  ░██░▓██▒  ▐▌██▒▓██ █▄      ▒   ██▒▒██▄█▓▒ ▒▒██░   ░██▄▄▄▄██░ ▓██▓ ░
 *  ░██░▒██░   ▓██░▒██▒ █▄   ▒██████▒▒▒██▒ ░  ░░██████▒▓█   ▓██▒ ▒██▒ ░
 *  ░▓  ░ ▒░   ▒ ▒ ▒ ▒▒ ▓▒   ▒ ▒▓▒ ▒ ░▒▓▒░ ░  ░░ ▒░▓  ░▒▒   ▓▒█░ ▒ ░░
 *  ▒ ░░ ░░   ░ ▒░░ ░▒ ▒░   ░ ░▒  ░ ░░▒ ░     ░ ░ ▒  ░ ▒   ▒▒ ░   ░
 *  ▒ ░   ░   ░ ░ ░ ░░ ░    ░  ░  ░  ░░         ░ ░    ░   ▒    ░
 *  ░           ░ ░  ░            ░               ░  ░     ░  ░
 * 
 * LICENSE: MIT
 */
class A {}
class B extends A {}
class C extends B {}

console.log(C === C); // true
console.log('typeof C =', typeof C); // function
console.log(C.prototype instanceof C); // true
console.log(C.prototype instanceof B); // true
console.log(C.prototype instanceof A); // true

const Ci = new C();
console.log(Ci === Ci);
console.log('typeof Ci =', typeof Ci); // function
console.log(Ci instanceof C); // true
console.log(Ci instanceof B); // true
console.log(Ci instanceof A); // true