What is the purpose of this code?

Baba — Mon, 27 Sep 2021 07:54:43 +0000

Today I was playing with the Object.defineProperty method and doing weird stuffs like making the 3rd index of an Array to 🔥always🔥 return 'Frank Stallone' (don't ask why)

console.log([1,2,3,4][3]); // Frank Stallone

anyways

I added debugger statement to set method of a descriptor:

Object.defineProperty(Array.prototype, 3, {
  set() { debugger; }
});

after typing something to the console triggers debugger with 2 calls in the call stack:

Code snippet in the first call:

(function i(t) {
    let e;
    e = "string" === t ? new String("") : "number" === t ? new Number(0) : "bigint" === t ? Object(BigInt(0)) : "boolean" === t ? new Boolean(!1) : this;
    const s = [];
    try {
        for (let i = e; i; i = Object.getPrototypeOf(i)) {
            if (("array" === t || "typedarray" === t) && i === e && i.length > 9999)
                continue;
            const n = {
                items: [],
                title: void 0,
                __proto__: null
            };
            try {
                "object" == typeof i && Object.prototype.hasOwnProperty.call(i, "constructor") && i.constructor && i.constructor.name && (n.title = i.constructor.name)
            } catch (t) {}
            s[s.length] = n;
            const o = Object.getOwnPropertyNames(i)
              , r = Array.isArray(i);
            for (let t = 0; t < o.length && n.items.length < 1e4; ++t)
                r && /^[0-9]/.test(o[t]) || (n.items[n.items.length] = o[t])
        }
    } catch (t) {}
    return s
}
)

DEV Community: Baba

What is the purpose of this code?

Can someone explain to me what is the purpose of this code? and what it does?