Add meta package to datastore.

service/datastore/meta/namespaces_test.go

Index: service/datastore/meta/namespaces_test.go
diff --git a/service/datastore/meta/namespaces_test.go b/service/datastore/meta/namespaces_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..dc68d9a1c86d30d71d3100d6114c262fba724745
--- /dev/null
+++ b/service/datastore/meta/namespaces_test.go
@@ -0,0 +1,71 @@
+// 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.
+
+package meta
+
+import (
+	"testing"
+
+	"github.com/luci/gae/impl/memory"
+	"github.com/luci/gae/service/datastore"
+	"github.com/luci/gae/service/info"
+	"golang.org/x/net/context"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestNamespaces(t *testing.T) {
+	t.Parallel()
+
+	Convey(`A testing datastore`, t, func() {
+		ctx := memory.Use(context.Background())
+
+		// Call to add a datastore entry under the supplied namespace.
+		addNamespace := func(ns string) {
+			if ns != "" {
+				ctx = info.Get(ctx).MustNamespace(ns)
+			}
+
+			err := datastore.Get(ctx).Raw().PutMulti(
+				[]*datastore.Key{
+					datastore.Get(ctx).NewKey("Warblegarble", "", 1, nil),
+				},
+				[]datastore.PropertyMap{
+					make(datastore.PropertyMap),
+				},
+				func(*datastore.Key, error) error { return nil })
+			if err != nil {
+				panic(err)
+			}
+
+			datastore.Get(ctx).Testable().CatchupIndexes()
+		}
+
+		Convey(`A datastore with no namespaces returns {}.`, func() {
+			var coll NamespacesCollector
+			So(Namespaces(ctx, coll.Callback), ShouldBeNil)
+			So(coll, ShouldResemble, NamespacesCollector(nil))
+		})
+
+		Convey(`With namespaces {<default>, foo, bar, baz-a, baz-b}`, func() {
+			addNamespace("")
+			addNamespace("foo")
+			addNamespace("bar")
+			addNamespace("baz-a")
+			addNamespace("baz-b")
+
+			Convey(`Can collect all namespaces.`, func() {
+				var coll NamespacesCollector
+				So(Namespaces(ctx, coll.Callback), ShouldBeNil)
+				So(coll, ShouldResemble, NamespacesCollector{"", "bar", "baz-a", "baz-b", "foo"})
+			})
+
+			Convey(`Can get namespaces with prefix "baz-".`, func() {
+				var coll NamespacesCollector
+				So(NamespacesWithPrefix(ctx, "baz-", coll.Callback), ShouldBeNil)
+				So(coll, ShouldResemble, NamespacesCollector{"baz-a", "baz-b"})
+			})
+		})
+	})
+}