Tampermonkey Userscript - Keybind Numbered Google Results Select

.js

// ==UserScript==
// @name         Google digits
// @include      https://www.google.tld/*
// @run-at       document-start
// ==/UserScript==

// only work on search pages with #q= &q= ?q= 
if (location.href.match(/[#&?]q=/)) {
    window.addEventListener('keydown', function(e) {
        var digit = e.keyCode - 48;
        // 48 is the code for '0'
        if (digit >= 1 && digit <= 9 &&
            // don't intercept if a modifier key is held
            !e.altKey && !e.ctrlKey && !e.shiftKey && !e.metaKey &&
            // don't intercept 1-9 in the search input
            e.target.localName != 'input')
        {
            // get all results in an array
            var links = document.querySelectorAll('h3.r a');
            // arrays are 0-based
            var link = links[digit - 1];
            if (link) {
                // go to the linked URL
                location.href = link.href;
                // prevent site from seeing this keyboard event
                e.preventDefault();
                e.stopPropagation();
                e.stopImmediatePropagation();
            }
        }
    }, true); // true means we capture the event before it's "bubbled" down
}