uint-8-array.polyfill.js

/**
 * Uint8Array.prototype.at()
 * version 0.0.0
 * Feature	        Chrome  Firefox Internet Explorer   Opera	Safari	Edge
 * Basic support    No      No      No                  No    No      No
 * -------------------------------------------------------------------------------
 */
 if (!Uint8Array.prototype.at) {
  Object.defineProperty(Uint8Array.prototype, "at",
    {
      value: function (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];
      },
      writable: true,
      enumerable: false,
      configurable: true
    });
}