// ==UserScript==
// @name Array.at polyfill
// @run-at document-start
// @match https://*.linkedin.com/*
// ==/UserScript==
// Based on: https://github.com/tc39/proposal-relative-indexing-method#polyfill

function at(n) {
	// ToInteger() abstract op
	n = Math.trunc(n) || 0;
	// Allow negative indexing from the end
	if (n < 0) n += this.length;
	// OOB access is guaranteed to return undefined
	if (n < 0 || n >= this.length) return undefined;
	// Otherwise, this is just normal property access
	return this[n];
}

const TypedArray = Reflect.getPrototypeOf(Int8Array);
for (const C of [Array, String, TypedArray]) {
	Object.defineProperty(C.prototype, "at",
		{ value: at,
			writable: true,
			enumerable: false,
			configurable: true });
}