Convert 'Testable' interface into an optional filter.

go/src/infra/gae/libs/gae/filters/featureBreaker/featurebreaker_test.go

Index: go/src/infra/gae/libs/gae/filters/featureBreaker/featurebreaker_test.go
diff --git a/go/src/infra/gae/libs/gae/filters/featureBreaker/featurebreaker_test.go b/go/src/infra/gae/libs/gae/filters/featureBreaker/featurebreaker_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..d2bb0acfcaad4d7331304979b104e52d276855f8
--- /dev/null
+++ b/go/src/infra/gae/libs/gae/filters/featureBreaker/featurebreaker_test.go
@@ -0,0 +1,60 @@
+// 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 featureBreaker
+
+import (
+	"errors"
+	"golang.org/x/net/context"
+	"testing"
+
+	"infra/gae/libs/gae"
+	"infra/gae/libs/gae/memory"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestBrokenFeatures(t *testing.T) {
+	t.Parallel()
+
+	e := errors.New("default err")
+
+	Convey("BrokenFeatures", t, func() {
+		c := memory.Use(context.Background())
+
+		Convey("Can break rds", func() {
+			Convey("without a default", func() {
+				c, bf := FilterRDS(c, nil)
+				rds := gae.GetRDS(c)
+
+				Convey("by specifying an error", func() {
+					bf.BreakFeatures(e, "Get", "Put")
+					So(rds.Get(nil, nil), ShouldEqual, e)
+
+					Convey("and you can unbreak them as well", func() {
+						bf.UnbreakFeatures("Get")
+						So(rds.Get(nil, nil), ShouldEqual, gae.ErrDSInvalidKey)
+
+						Convey("no broken features at all is a shortcut", func() {
+							bf.UnbreakFeatures("Put")
+							So(rds.Get(nil, nil), ShouldEqual, gae.ErrDSInvalidKey)
+						})
+					})
+				})
+
+				Convey("Not specifying an error gets you a generic error", func() {
+					bf.BreakFeatures(nil, "Get")
+					So(rds.Get(nil, nil).Error(), ShouldEqual, `feature "Get" is broken`)
+				})
+			})
+
+			Convey("with a default", func() {
+				c, bf := FilterRDS(c, e)
+				rds := gae.GetRDS(c)
+				bf.BreakFeatures(nil, "Get")
+				So(rds.Get(nil, nil), ShouldEqual, e)
+			})
+		})
+	})
+}