Add babel for es2015

.babelrc

@@ -0,0 +1,7 @@
+{
+  "env": {
+    "esm": {
+      "presets": ["es2015"]
+    }
+  }
+}

.gitignore

@@ -1 +1,2 @@
 node_modules
+dist

index.js

@@ -6,10 +6,9 @@
   }
 }(this, function() {
   function scanForProblems(context, logError) {
-    var i
     var imgElements = context.querySelectorAll('img')
 
-    for (i = 0; i < imgElements.length; i++) {
+    for (let i = 0; i < imgElements.length; i++) {
       var img = imgElements[i]
       if (!img.hasAttribute('alt')) {
         logError(new ImageWithoutAltAttributeError(img))
@@ -17,7 +16,7 @@
     }
 
     var aElements = context.querySelectorAll('a')
-    for (i = 0; i < aElements.length; i++) {
+    for (let i = 0; i < aElements.length; i++) {
       var a = aElements[i]
       if (a.hasAttribute('name') || elementIsHidden(a)) {
         continue
@@ -30,7 +29,7 @@
     }
 
     var buttonElements = context.querySelectorAll('button')
-    for (i = 0; i < buttonElements.length; i++) {
+    for (let i = 0; i < buttonElements.length; i++) {
       var button = buttonElements[i]
       if (!elementIsHidden(button) && !accessibleText(button)) {
         logError(new ButtonWithoutLabelError(button))
@@ -38,7 +37,7 @@
     }
 
     var labelElements = context.querySelectorAll('label')
-    for (i = 0; i < labelElements.length; i++) {
+    for (let i = 0; i < labelElements.length; i++) {
       var label = labelElements[i]
       // In case label.control isn't supported by browser, find the control manually (IE)
       var control = label.control || document.getElementById(label.getAttribute('for')) || label.querySelector('input')
@@ -49,7 +48,7 @@
     }
 
     var inputElements = context.querySelectorAll('input[type=text], textarea')
-    for (i = 0; i < inputElements.length; i++) {
+    for (let i = 0; i < inputElements.length; i++) {
       var input = inputElements[i]
       // In case input.labels isn't supported by browser, find the control manually (IE)
       var inputLabel = input.labels ? input.labels[0] : input.closest('label') || document.querySelector('label[for="' + input.id + '"]')

package.json

@@ -4,7 +4,8 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "test": "eslint *.js"
+    "test": "eslint *.js",
+    "build": "BABEL_ENV=esm babel index.js -o dist/index-esm.js"
   },
   "repository": {
     "type": "git",
@@ -18,6 +19,10 @@
   },
   "homepage": "https://github.com/github/accessibilityjs#readme",
   "devDependencies": {
+    "babel-cli": "^6.26.0",
+    "babel-eslint": "^8.0.1",
+    "babel-preset-es2015": "^6.24.1",
+    "babel-register": "^6.26.0",
     "eslint": "^4.8.0"
   }
 }