Add ES2015 test.

.babelrc

@@ -0,0 +1,3 @@
+{
+  "presets": ["es2015"]
+}

package.json

@@ -40,6 +40,9 @@
     "parse-json": "^2.2.0"
   },
   "devDependencies": {
+    "babel-core": "^6.21.0",
+    "babel-preset-es2015": "^6.18.0",
+    "babel-register": "^6.18.0",
     "eslint": "^3.13.0",
     "eslint-config-davidtheclark-node": "^0.2.0",
     "eslint-plugin-node": "^3.0.5",

test/failed-directories.test.js

@@ -226,7 +226,7 @@ test('find invalid JS in .config.js file', function (assert) {
         callback({ code: 'ENOENT' });
         break;
       case absolutePath('a/b/foo.config.js'):
-        callback(null, 'module.exports = { found: true: false,');
+        callback(null, '/* woot */');
         break;
       default:
         callback(new Error('irrelevant path ' + searchPath));

test/fixtures/foo.babel.js

@@ -0,0 +1,2 @@
+const foo = true;
+export default {foo};

test/successful-files.test.js

@@ -4,6 +4,10 @@ var test = require('tape');
 var path = require('path');
 var cosmiconfig = require('..');
 
+require('babel-register')({
+  only: /\.babel\.js$/,
+});
+
 function absolutePath(str) {
   return path.join(__dirname, str);
 }
@@ -47,6 +51,19 @@ test('defined JS config path', function (assert) {
   });
 });
 
+test('defined ES6 config path', function (assert) {
+  var loadConfig = cosmiconfig().load;
+  loadConfig(null, absolutePath('fixtures/foo.babel.js')).then(function (result) {
+    assert.deepEqual(result.config, {
+      foo: true,
+    });
+    assert.equal(result.filepath, absolutePath('fixtures/foo.babel.js'));
+    assert.end();
+  }).catch(function (err) {
+    assert.end(err);
+  });
+});
+
 test('defined modulized JS config path', function (assert) {
   var loadConfig = cosmiconfig().load;
   loadConfig(null, absolutePath('fixtures/foo-module.js')).then(function (result) {