Add a MustNamespace that panics if the namespace wasn't valid

impl/memory/info_test.go

Index: impl/memory/info_test.go
diff --git a/impl/memory/info_test.go b/impl/memory/info_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..6c7fbac611825bb30f14f23e1a7a23aa007a58e1
--- /dev/null
+++ b/impl/memory/info_test.go
@@ -0,0 +1,28 @@
+// 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 memory
+
+import (
+	"testing"
+
+	"github.com/luci/gae/service/info"
+	"golang.org/x/net/context"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestMustNamespace(t *testing.T) {
+	Convey("MustNamespace panics", t, func() {
+		c := Use(context.Background())
+		i := info.Get(c)
+
+		So(func() {
+			i.MustNamespace("valid_namespace_name")
+		}, ShouldNotPanic)
+		So(func() {
+			i.MustNamespace("invalid namespace name")
+		}, ShouldPanic)
+	})
+}