Add testable interface for datastore.

service/datastore/index_test.go

Index: service/datastore/index_test.go
diff --git a/service/datastore/index_test.go b/service/datastore/index_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..2667534c791f2401fe334f5ba0427824d042c36e
--- /dev/null
+++ b/service/datastore/index_test.go
@@ -0,0 +1,92 @@
+// 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"
+	"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.Builtin(), ShouldBeTrue)
+			So(id.Compound(), ShouldBeFalse)
+			So(id.String(), ShouldEqual, "B:kind/prop")
+
+			id.SortBy = append(id.SortBy, IndexColumn{"other", DESCENDING})
+			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})
+			So(id.Builtin(), ShouldBeFalse)
+			So(id.Compound(), ShouldBeFalse)
+		})
+
+		Convey("binary", func() {
+			id := IndexDefinition{Kind: "kind"}
+			buf := &bytes.Buffer{}
+			So(id.Write(buf), ShouldBeNil)
+			So(bytes.HasPrefix(buf.Bytes(), IndexBuiltinQueryPrefix()), ShouldBeTrue)
+			newId := IndexDefinition{}
+			So(newId.Read(buf), ShouldBeNil)
+			So(newId, ShouldResemble, id)
+
+			id.SortBy = append(id.SortBy, IndexColumn{Property: "prop"})
+			buf = &bytes.Buffer{}
+			So(id.Write(buf), ShouldBeNil)
+			So(bytes.HasPrefix(buf.Bytes(), IndexBuiltinQueryPrefix()), ShouldBeTrue)
+			newId = IndexDefinition{}
+			So(newId.Read(buf), ShouldBeNil)
+			So(newId, ShouldResemble, id)
+
+			id.SortBy = append(id.SortBy, IndexColumn{"other", DESCENDING})
+			id.Ancestor = true
+			buf = &bytes.Buffer{}
+			So(id.Write(buf), ShouldBeNil)
+			So(bytes.HasPrefix(buf.Bytes(), IndexComplexQueryPrefix()), ShouldBeTrue)
+			newId = IndexDefinition{}
+			So(newId.Read(buf), ShouldBeNil)
+			So(newId, ShouldResemble, id)
+
+			// invalid
+			id.SortBy = append(id.SortBy, IndexColumn{"", DESCENDING})
+			buf = &bytes.Buffer{}
+			So(id.Write(buf), ShouldBeNil)
+			So(bytes.HasPrefix(buf.Bytes(), IndexComplexQueryPrefix()), ShouldBeTrue)
+			newId = IndexDefinition{}
+			So(newId.Read(buf), ShouldBeNil)
+			So(newId, ShouldResemble, id)
+		})
+
+		Convey("too many", func() {
+			id := IndexDefinition{Kind: "wat"}
+			for i := 0; i < MaxIndexColumns+1; i++ {
+				id.SortBy = append(id.SortBy, IndexColumn{"Hi", ASCENDING})
+			}
+			buf := &bytes.Buffer{}
+			So(id.Write(buf), ShouldBeNil)
+			newId := IndexDefinition{}
+			So(newId.Read(buf).Error(), ShouldContainSubstring, "over 64 sort orders")
+		})
+	})
+}