Reland: Refactor current GAE abstraction library to be free of the SDK*

go/src/infra/gae/libs/gae/upstream_errors_test.go

Index: go/src/infra/gae/libs/gae/upstream_errors_test.go
diff --git a/go/src/infra/gae/libs/gae/upstream_errors_test.go b/go/src/infra/gae/libs/gae/upstream_errors_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..a5a2e8276454482ce4eabd22ab326b6ecfafb037
--- /dev/null
+++ b/go/src/infra/gae/libs/gae/upstream_errors_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 gae
+
+import (
+	"errors"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+type otherMEType []error
+
+func (o otherMEType) Error() string { return "FAIL" }
+
+func TestUpstreamErrors(t *testing.T) {
+	t.Parallel()
+
+	Convey("Test MultiError", t, func() {
+		Convey("nil", func() {
+			me := MultiError(nil)
+			So(me.Error(), ShouldEqual, "(0 errors)")
+			Convey("single", func() {
+				So(SingleError(error(me)), ShouldBeNil)
+			})
+		})
+		Convey("one", func() {
+			me := MultiError{errors.New("sup")}
+			So(me.Error(), ShouldEqual, "sup")
+		})
+		Convey("two", func() {
+			me := MultiError{errors.New("sup"), errors.New("what")}
+			So(me.Error(), ShouldEqual, "sup (and 1 other error)")
+		})
+		Convey("more", func() {
+			me := MultiError{errors.New("sup"), errors.New("what"), errors.New("nerds")}
+			So(me.Error(), ShouldEqual, "sup (and 2 other errors)")
+
+			Convey("single", func() {
+				So(SingleError(error(me)), ShouldResemble, errors.New("sup"))
+			})
+		})
+		Convey("convert", func() {
+			ome := otherMEType{errors.New("sup")}
+			So(FixError(ome), ShouldHaveSameTypeAs, MultiError{})
+		})
+	})
+
+	Convey("FixError passes through", t, func() {
+		e := errors.New("unique")
+		So(FixError(e), ShouldEqual, e)
+	})
+
+	Convey("SingleError passes through", t, func() {
+		e := errors.New("unique")
+		So(SingleError(e), ShouldEqual, e)
+	})
+}