Only allow safe identifiers as object keys (Fixes #416)

packages/babel-plugin-transform-property-literals/src/index.js

@@ -1,5 +1,12 @@
 "use strict";
 
+const safeIdentifierRegExp = /[^a-z0-9$_]/i;
+
+function isSafeKeyIdentifier(value) {
+  return !safeIdentifierRegExp.test(value)
+}
+
+
 module.exports = function({ types: t }) {
   return {
     name: "transform-property-literals",
@@ -8,14 +15,24 @@ module.exports = function({ types: t }) {
       ObjectProperty: {
         exit({ node }) {
           const key = node.key;
+
+          // Handle the case where the incoming property key may not be a safe
+          // identifier that works in all browsers
+          if (t.isIdentifier(key)) {
+            if (!isSafeKeyIdentifier(key.name)) {
+              node.key = t.stringLiteral(key.name);
+            }
+            return;
+          }
+
           if (!t.isStringLiteral(key)) {
             return;
           }
 
           if (key.value.match(/^\d+$/)) {
             node.key = t.numericLiteral(parseInt(node.key.value, 10));
             node.computed = false;
-          } else if (t.isValidIdentifier(key.value)) {
+          } else if (isSafeKeyIdentifier(key.value)) {
             node.key = t.identifier(key.value);
             node.computed = false;
           }