feat(embed): create GitHub Corners embed script

http://tholman.com/github-corners/

Author: remarkablemark

package.json

@@ -3,7 +3,7 @@
   "version": "0.0.0",
   "description": "Embed script for GitHub Corners.",
   "author": "Mark <[email protected]>",
-  "main": "index.js",
+  "main": "src/index.js",
   "scripts": {
     "commitmsg": "commitlint -e $GIT_PARAMS",
     "lint": "eslint --ignore-path .gitignore .",

src/embed.js

@@ -0,0 +1,48 @@
+(function(doc, script, anchor, target, style) {
+  // get currently executing script
+  script = doc.currentScript || doc.scripts[doc.scripts.length - 1];
+
+  /**
+   * Gets value from script dataset.
+   *
+   * @param  {String} key
+   * @return {String}
+   */
+  function getData(key) {
+    return (
+      script.dataset ? script.dataset[key] : script.getAttribute('data-' + key)
+    );
+  }
+
+  // create anchor element
+  anchor = doc.createElement('a');
+
+  // anchor element attributes
+  anchor.href = getData('href')
+  anchor.className = 'github-corner';
+  anchor.setAttribute('aria-label', getData('label') || 'View source on Github');
+  target = getData('target');
+  if (target) {
+    anchor.setAttribute('target', target);
+    if (target === '_blank') {
+      anchor.setAttribute('rel', 'noopener noreferrer');
+    }
+  }
+
+  // anchor element content
+  anchor.innerHTML = (
+    '<svg width="80" height="80" viewBox="0 0 250 250" style="fill:#151513;color:#fff;position:absolute;top:0;border:0;right:0;" aria-hidden="true"><path d="M0,0 L115,115 L130,115 L142,142 L250,250 L250,0 Z"></path><path d="M128.3,109.0 C113.8,99.7 119.0,89.6 119.0,89.6 C122.0,82.7 120.5,78.6 120.5,78.6 C119.2,72.0 123.4,76.3 123.4,76.3 C127.3,80.9 125.5,87.3 125.5,87.3 C122.9,97.6 130.6,101.9 134.4,103.2" fill="currentColor" style="transform-origin:130px 106px;" class="octo-arm"></path><path d="M115.0,115.0 C114.9,115.1 118.7,116.5 119.8,115.4 L133.7,101.6 C136.9,99.2 139.9,98.4 142.2,98.6 C133.8,88.0 127.5,74.4 143.8,58.0 C148.5,53.4 154.0,51.2 159.7,51.0 C160.3,49.4 163.2,43.6 171.4,40.1 C171.4,40.1 176.1,42.5 178.8,56.2 C183.1,58.6 187.2,61.8 190.9,65.4 C194.5,69.0 197.7,73.2 200.1,77.6 C213.8,80.2 216.3,84.9 216.3,84.9 C212.7,93.1 206.9,96.0 205.4,96.6 C205.1,102.4 203.0,107.8 198.3,112.5 C181.9,128.9 168.3,122.5 157.7,114.1 C157.9,116.9 156.7,120.9 152.7,124.9 L141.0,136.5 C139.8,137.7 141.6,141.9 141.8,141.8 Z" fill="currentColor" class="octo-body"></path></svg>'
+  );
+
+  // style element
+  style = doc.createElement('style');
+
+  // style element content
+  style.innerHTML = (
+    '.github-corner:hover .octo-arm{animation:octocat-wave 560ms ease-in-out}@keyframes octocat-wave{0%,100%{transform:rotate(0)}20%,60%{transform:rotate(-25deg)}40%,80%{transform:rotate(10deg)}}@media (max-width:500px){.github-corner:hover .octo-arm{animation:none}.github-corner .octo-arm{animation:octocat-wave 560ms ease-in-out}}'
+  );
+
+  // append respective elements to head and body
+  doc.head.appendChild(style);
+  doc.body.appendChild(anchor);
+})(document);