fix #75

src/scope.js

@@ -56,15 +56,17 @@ var Scope = {
     }
     var key = paths.shift()
     var value = getValueFromScopes(key, scopes)
-    return paths.reduce(
-      (value, key) => {
-        if (_.isNil(value)) {
-          throw new TypeError('undefined variable: ' + key)
-        }
-        return getValueFromParent(key, value)
-      },
-      value
-    )
+    if (_.isNil(value)) {
+      throw new TypeError('undefined variable: ' + key)
+    }
+    while (paths.length) {
+      key = paths.shift()
+      value = getValueFromParent(key, value)
+      if (_.isNil(value)) {
+        throw new TypeError('undefined variable: ' + key)
+      }
+    }
+    return value
   },
 
   /*

test/scope.js

@@ -151,12 +151,18 @@ describe('scope', function () {
       }
       expect(fn).to.throw(/undefined variable: notdefined/)
     })
-    it('should throw when deep variable not exist', function () {
-      scope.set('foo', 'bar')
+    it('should throw when parent not defined', function () {
       function fn () {
         scope.get('foo.bar.not.defined')
       }
-      expect(fn).to.throw(/undefined variable: not/)
+      expect(fn).to.throw(/undefined variable: bar/)
+    })
+    it('should throw when itself not defined', function () {
+      scope.set('foo', 'bar')
+      function fn () {
+        scope.get('foo.BAR')
+      }
+      expect(fn).to.throw(/undefined variable: BAR/)
     })
     it('should find variable in parent scope', function () {
       scope.set('foo', 'foo')