GAE Datastore - Fix derived types not being reflected properly

service/datastore/pls_test.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // adapted from github.com/golang/appengine/datastore
 
 package datastore
 
 import (
         "bytes"
@@ skipping 1868 matching lines @@
                         v, err := mgs.GetMeta("val")
                         So(err, ShouldBeNil)
                         So(v, ShouldEqual, int64(100))
 
                         o.Val = 10
                         v, err = mgs.GetMeta("val")
                         So(err, ShouldBeNil)
                         So(v, ShouldEqual, int64(10))
                 })
 
+                Convey("Derived metadata fields", func() {
+                        type DerivedString string
+                        type DerivedInt int16
+                        type DerivedStruct struct {
+                                ID  DerivedString `gae:"$id"`
+                                Foo DerivedInt    `gae:"$foo"`
+                        }
+                        o := &DerivedStruct{"hello", 10}
+                        mgs := getMGS(o)
+                        v, err := mgs.GetMeta("id")
+                        So(err, ShouldBeNil)
+                        So(v, ShouldEqual, "hello")
+
+                        v, err = mgs.GetMeta("foo")
+                        So(err, ShouldBeNil)
+                        So(v, ShouldEqual, int64(10))
+
+                        So(mgs.SetMeta("id", "nerds"), ShouldBeNil)
+                        So(mgs.SetMeta("foo", 20), ShouldBeNil)
+                        So(o.ID, ShouldEqual, DerivedString("nerds"))
+                        So(o.Foo, ShouldEqual, DerivedInt(20))
+                })
+
                 Convey("Bad default meta type", func() {
                         type BadDefault struct {
                                 Val time.Time `gae:"$meta,tomorrow"`
                         }
                         pls := GetPLS(&BadDefault{})
                         So(pls.Problem().Error(), ShouldContainSubstring, "bad type")
                 })
 
                 Convey("MetaGetterSetter implementation (IDParser)", func() {
                         idp := &IDParser{parent: "moo", id: 100}
@@ skipping 55 matching lines @@
                         So(pls.SetMeta("id", "sup|1337"), ShouldBeNil)
                         So(ide.EmbeddedID, ShouldResemble, EmbeddedID{"sup", 1337})
 
                         So(pls.GetAllMeta(), ShouldResembleV, PropertyMap{
                                 "$id":   {mpNI("sup|1337")},
                                 "$kind": {mpNI("IDEmbedder")},
                         })
                 })
         })
 }