Refactor keys and queries in datastore service and implementation.

service/datastore/index_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 (
         "testing"
 
         . "github.com/smartystreets/goconvey/convey"
 )
 
 func TestIndexDefinition(t *testing.T) {
         t.Parallel()
 
         Convey("Test IndexDefinition", t, func() {
                 Convey("basic", func() {
                         id := IndexDefinition{Kind: "kind"}
 
                         So(id.Builtin(), ShouldBeTrue)
                         So(id.Compound(), ShouldBeFalse)
                         So(id.String(), ShouldEqual, "B:kind")
 
                         id.SortBy = append(id.SortBy, IndexColumn{Property: "prop"})
-                        So(id.SortBy[0].Direction, ShouldEqual, ASCENDING)
+                        So(id.SortBy[0].Descending, ShouldBeFalse)
                         So(id.Builtin(), ShouldBeTrue)
                         So(id.Compound(), ShouldBeFalse)
                         So(id.String(), ShouldEqual, "B:kind/prop")
 
-                        id.SortBy = append(id.SortBy, IndexColumn{"other", DESCENDING})
+                        id.SortBy = append(id.SortBy, IndexColumn{Property: "other", Descending: true})
                         id.Ancestor = true
                         So(id.Builtin(), ShouldBeFalse)
                         So(id.Compound(), ShouldBeTrue)
                         So(id.String(), ShouldEqual, "C:kind|A/prop/-other")
 
                         // invalid
-                        id.SortBy = append(id.SortBy, IndexColumn{"", DESCENDING})
+                        id.SortBy = append(id.SortBy, IndexColumn{Property: "", Descending: true})
                         So(id.Builtin(), ShouldBeFalse)
                         So(id.Compound(), ShouldBeFalse)
                 })
         })
 }