open-in-godoc.js

// ==UserScript==
// @name         Open in godoc
// @namespace    https://github.com/knight42
// @version      0.1
// @description  Open godoc from GitHub
// @author       knight42
// @include      https://github.com/*/*
// @exclude      https://github.com/*/*/blob/*
// @exclude      https://github.com/settings/*
// @exclude      https://github.com/orgs/*
// @exclude      https://github.com/organizations/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    var grp = document.querySelector('div.BtnGroup')
    var godocLink = document.createElement('a');
    var pathname = document.location.pathname.slice(1);
    var parts = pathname.split('/');
    var godocOrg = parts[0] === 'kubernetes' ? 'k8s.io' : parts[0];
    var godocPath = pathname.slice(parts[0].length).replace(/tree\/[^/]+\//, '');
    godocLink.classList.add('btn', 'btn-sm', 'BtnGroup-item')
    godocLink.id = 'godoc'
    godocLink.innerText = 'Open in godoc'
    godocLink.href = `https://godoc.org/${godocOrg}${godocPath}`;
    grp.prepend(godocLink);
})();