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

impl/memory/info.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.
 
 package memory
 
 import (
         "fmt"
         "regexp"
 
@@ skipping 38 matching lines @@
         return gi.namespace
 }
 
 func (gi *giImpl) Namespace(ns string) (ret context.Context, err error) {
         if !validNamespace.MatchString(ns) {
                 return nil, fmt.Errorf("appengine: namespace %q does not match /%s/", ns, validNamespace)
         }
         return context.WithValue(gi.c, giContextKey, &globalInfoData{gi.appid, ns}), nil
 }
 
+func (gi *giImpl) MustNamespace(ns string) context.Context {
+        ret, err := gi.Namespace(ns)
+        if err != nil {
+                panic(err)
+        }
+        return ret
+}
+
 func (gi *giImpl) AppID() string {
         return gi.appid
 }
 
 func (gi *giImpl) FullyQualifiedAppID() string {
         return gi.appid
 }
 
 func (gi *giImpl) IsDevAppServer() bool {
         return true
 }
 
 func (gi *giImpl) VersionID() string {
         // VersionID returns X.Y where Y is autogenerated by appengine, and X is
         // whatever's in app.yaml.
         return "testVersionID.1"
 }