Better attempt at an appengine wrapper.

go/src/infra/gae/libs/wrapper/dummy.go

Index: go/src/infra/gae/libs/wrapper/dummy.go
diff --git a/go/src/infra/gae/libs/wrapper/dummy.go b/go/src/infra/gae/libs/wrapper/dummy.go
new file mode 100644
index 0000000000000000000000000000000000000000..8bc85107a89f722130fb2e8b8e46dee704febb70
--- /dev/null
+++ b/go/src/infra/gae/libs/wrapper/dummy.go
@@ -0,0 +1,185 @@
+// 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 wrapper
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+	"time"
+
+	"golang.org/x/net/context"
+
+	"appengine"
+	"appengine/datastore"
+	"appengine/memcache"
+	"appengine/taskqueue"
+
+	"github.com/mjibson/goon"
+)
+
+const niFmtStr = "wrapper: method %s.%s is not implemented"
+
+func ni() error {
+	iface := "UNKNOWN"
+	funcName := "UNKNOWN"
+
+	if ptr, _, _, ok := runtime.Caller(1); ok {
+		f := runtime.FuncForPC(ptr)
+		n := f.Name()
+		if n != "" {
+			parts := strings.Split(n, ".")
+			if len(parts) == 3 {
+				switch parts[1][len(parts[1])-2:] {

[M-A Ruel, 2015/05/25 17:14:51]

I highly recommend to check the package name too.

[iannucci, 2015/05/26 18:25:05]

ni() is internal to this package, so it's always going to be us

+				case "DS":
+					iface = "Datastore"
+				case "MC":
+					iface = "Memcache"
+				case "TQ":
+					iface = "TaskQueue"
+				case "GI":
+					iface = "GlobalInformation"
+				case "QY":
+					iface = "Query"
+				}
+				funcName = parts[2]

[M-A Ruel, 2015/05/25 17:14:51]

why no break?

[iannucci, 2015/05/26 18:25:06]

b/c there's no loop?

[M-A Ruel, 2015/05/27 00:27:10]

That ... is a good reason. I misread as a for loop.

+			}
+		}
+	}
+
+	return fmt.Errorf(niFmtStr, iface, funcName)
+}
+
+/////////////////////////////////// dummyDS ////////////////////////////////////
+
+type dummyDS struct{}
+
+func (dummyDS) Kind(interface{}) string                                     { panic(ni()) }
+func (dummyDS) KindNameResolver() goon.KindNameResolver                     { panic(ni()) }
+func (dummyDS) SetKindNameResolver(goon.KindNameResolver)                   { panic(ni()) }
+func (dummyDS) NewKey(string, string, int64, *datastore.Key) *datastore.Key { panic(ni()) }
+func (dummyDS) NewKeyObj(interface{}) *datastore.Key                        { panic(ni()) }
+func (dummyDS) NewKeyObjError(interface{}) (*datastore.Key, error)          { panic(ni()) }
+func (dummyDS) Put(interface{}) (*datastore.Key, error)                     { panic(ni()) }
+func (dummyDS) Get(interface{}) error                                       { panic(ni()) }
+func (dummyDS) Delete(*datastore.Key) error                                 { panic(ni()) }
+func (dummyDS) PutMulti(interface{}) ([]*datastore.Key, error)              { panic(ni()) }
+func (dummyDS) GetMulti(interface{}) error                                  { panic(ni()) }
+func (dummyDS) DeleteMulti([]*datastore.Key) error                          { panic(ni()) }
+func (dummyDS) NewQuery(string) DSQuery                                     { panic(ni()) }
+func (dummyDS) Run(DSQuery) DSIterator                                      { panic(ni()) }
+func (dummyDS) GetAll(DSQuery, interface{}) ([]*datastore.Key, error)       { panic(ni()) }
+func (dummyDS) Count(DSQuery) (int, error)                                  { panic(ni()) }
+func (dummyDS) RunInTransaction(func(context.Context) error, *datastore.TransactionOptions) error {
+	panic(ni())
+}
+
+var dummyDSInst = dummyDS{}
+
+// DummyDS returns a dummy Datastore implementation suitable for embedding.
+// Every method panics with a message containing the name of the method which
+// was unimplemented.
+func DummyDS() Datastore { return dummyDSInst }
+
+/////////////////////////////////// dummyMC ////////////////////////////////////
+
+type dummyMC struct{}
+
+func (dummyMC) Add(*memcache.Item) error                             { panic(ni()) }
+func (dummyMC) Set(*memcache.Item) error                             { panic(ni()) }
+func (dummyMC) Get(string) (*memcache.Item, error)                   { panic(ni()) }
+func (dummyMC) Delete(string) error                                  { panic(ni()) }
+func (dummyMC) CompareAndSwap(*memcache.Item) error                  { panic(ni()) }
+func (dummyMC) AddMulti([]*memcache.Item) error                      { panic(ni()) }
+func (dummyMC) SetMulti([]*memcache.Item) error                      { panic(ni()) }
+func (dummyMC) GetMulti([]string) (map[string]*memcache.Item, error) { panic(ni()) }
+func (dummyMC) DeleteMulti([]string) error                           { panic(ni()) }
+func (dummyMC) CompareAndSwapMulti([]*memcache.Item) error           { panic(ni()) }
+func (dummyMC) Increment(string, int64, uint64) (uint64, error)      { panic(ni()) }
+func (dummyMC) IncrementExisting(string, int64) (uint64, error)      { panic(ni()) }
+func (dummyMC) Flush() error                                         { panic(ni()) }
+func (dummyMC) Stats() (*memcache.Statistics, error)                 { panic(ni()) }
+func (dummyMC) InflateCodec(memcache.Codec) MCCodec                  { panic(ni()) }
+
+var dummyMCInst = dummyMC{}
+
+// DummyMC returns a dummy Memcache implementation suitable for embedding.
+// Every method panics with a message containing the name of the method which
+// was unimplemented.
+func DummyMC() Memcache { return dummyMCInst }
+
+/////////////////////////////////// dummyTQ ////////////////////////////////////
+
+type dummyTQ struct{}
+
+func (dummyTQ) Add(*taskqueue.Task, string) (*taskqueue.Task, error)           { panic(ni()) }
+func (dummyTQ) Delete(*taskqueue.Task, string) error                           { panic(ni()) }
+func (dummyTQ) AddMulti([]*taskqueue.Task, string) ([]*taskqueue.Task, error)  { panic(ni()) }
+func (dummyTQ) DeleteMulti([]*taskqueue.Task, string) error                    { panic(ni()) }
+func (dummyTQ) Lease(int, string, int) ([]*taskqueue.Task, error)              { panic(ni()) }
+func (dummyTQ) LeaseByTag(int, string, int, string) ([]*taskqueue.Task, error) { panic(ni()) }
+func (dummyTQ) ModifyLease(*taskqueue.Task, string, int) error                 { panic(ni()) }
+func (dummyTQ) Purge(string) error                                             { panic(ni()) }
+func (dummyTQ) QueueStats([]string, int) ([]taskqueue.QueueStatistics, error)  { panic(ni()) }
+
+var dummyTQInst = dummyTQ{}
+
+// DummyTQ returns a dummy TaskQueue implementation suitable for embedding.
+// Every method panics with a message containing the name of the method which
+// was unimplemented.
+func DummyTQ() TaskQueue { return dummyTQInst }
+
+/////////////////////////////////// dummyQY ////////////////////////////////////
+
+type dummyQY struct{}
+
+func (dummyQY) Ancestor(ancestor *datastore.Key) DSQuery           { panic(ni()) }
+func (dummyQY) Distinct() DSQuery                                  { panic(ni()) }
+func (dummyQY) End(c DSCursor) DSQuery                             { panic(ni()) }
+func (dummyQY) EventualConsistency() DSQuery                       { panic(ni()) }
+func (dummyQY) Filter(filterStr string, value interface{}) DSQuery { panic(ni()) }
+func (dummyQY) KeysOnly() DSQuery                                  { panic(ni()) }
+func (dummyQY) Limit(limit int) DSQuery                            { panic(ni()) }
+func (dummyQY) Offset(offset int) DSQuery                          { panic(ni()) }
+func (dummyQY) Order(fieldName string) DSQuery                     { panic(ni()) }
+func (dummyQY) Project(fieldNames ...string) DSQuery               { panic(ni()) }
+func (dummyQY) Start(c DSCursor) DSQuery                           { panic(ni()) }
+
+var dummyQYInst = dummyQY{}
+
+// DummyQY returns a dummy DSQuery implementation suitable for embedding.
+// Every method panics with a message containing the name of the method which
+// was unimplemented.
+func DummyQY() DSQuery { return dummyQYInst }
+
+/////////////////////////////////// dummyGI ////////////////////////////////////
+
+type dummyGI struct{}
+
+func (dummyGI) AccessToken(scopes ...string) (token string, expiry time.Time, err error) { panic(ni()) }
+func (dummyGI) AppID() string                                                            { panic(ni()) }
+func (dummyGI) ModuleHostname(module, version, instance string) (string, error)          { panic(ni()) }
+func (dummyGI) ModuleName() string                                                       { panic(ni()) }
+func (dummyGI) DefaultVersionHostname() string                                           { panic(ni()) }
+func (dummyGI) PublicCertificates() ([]appengine.Certificate, error)                     { panic(ni()) }
+func (dummyGI) RequestID() string                                                        { panic(ni()) }
+func (dummyGI) ServiceAccount() (string, error)                                          { panic(ni()) }
+func (dummyGI) SignBytes(bytes []byte) (keyName string, signature []byte, err error)     { panic(ni()) }
+func (dummyGI) VersionID() string                                                        { panic(ni()) }
+func (dummyGI) Namespace(namespace string) (context.Context, error)                      { panic(ni()) }
+func (dummyGI) Datacenter() string                                                       { panic(ni()) }
+func (dummyGI) InstanceID() string                                                       { panic(ni()) }
+func (dummyGI) IsDevAppserver() bool                                                     { panic(ni()) }
+func (dummyGI) ServerSoftware() string                                                   { panic(ni()) }
+func (dummyGI) IsCapabilityDisabled(err error) bool                                      { panic(ni()) }
+func (dummyGI) IsOverQuota(err error) bool                                               { panic(ni()) }
+func (dummyGI) IsTimeoutError(err error) bool                                            { panic(ni()) }
+
+var dummyGIInst = dummyGI{}
+
+// DummyGI returns a dummy GlobalInfo implementation suitable for embedding.
+// Every method panics with a message containing the name of the method which
+// was unimplemented.
+func DummyGI() GlobalInfo { return dummyGIInst }