Add tests for binary_tools functions

service/datastore/serialize/binary_tools_test.go

Index: service/datastore/serialize/binary_tools_test.go
diff --git a/service/datastore/serialize/binary_tools_test.go b/service/datastore/serialize/binary_tools_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..d10495bf56b9f4b1bd349e7b862b2dd25034a25c
--- /dev/null
+++ b/service/datastore/serialize/binary_tools_test.go
@@ -0,0 +1,71 @@
+// 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 serialize
+
+import (
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestBinaryTools(t *testing.T) {
+	t.Parallel()
+
+	Convey("Test Join", t, func() {
+		Convey("returns bytes with nil separator", func() {
+			join := Join([]byte("hello"), []byte("world"))
+			So(join, ShouldResemble, []byte("helloworld"))
+		})
+	})
+
+	Convey("Test Invert", t, func() {
+		Convey("returns nil for nil input", func() {
+			inv := Invert(nil)
+			So(inv, ShouldBeNil)
+		})
+
+		Convey("returns nil for empty input", func() {
+			inv := Invert([]byte{})
+			So(inv, ShouldBeNil)
+		})
+
+		Convey("returns byte slice of same length as input", func() {
+			input := []byte("こんにちは, world")
+			inv := Invert(input)
+			So(len(input), ShouldEqual, len(inv))
+		})
+
+		Convey("returns byte slice with each byte inverted", func() {
+			inv := Invert([]byte("foo"))
+			So(inv, ShouldResemble, []byte{153, 144, 144})
+		})
+	})
+
+	Convey("Test Increment", t, func() {
+		Convey("returns empty slice and overflow true when input is nil", func() {
+			incr, overflow := Increment(nil)
+			So(incr, ShouldBeNil)
+			So(overflow, ShouldBeTrue)
+		})
+
+		Convey("returns empty slice and overflow true when input is empty", func() {
+			incr, overflow := Increment([]byte{})
+			So(incr, ShouldBeNil)
+			So(overflow, ShouldBeTrue)
+		})
+
+		Convey("handles overflow", func() {
+			incr, overflow := Increment([]byte{0xFF, 0xFF})
+			So(incr, ShouldResemble, []byte{0, 0})
+			So(overflow, ShouldBeTrue)
+		})
+
+		Convey("increments with overflow false when there is no overflow", func() {
+			incr, overflow := Increment([]byte{0xCA, 0xFF, 0xFF})
+			So(incr, ShouldResemble, []byte{0xCB, 0, 0})
+			So(overflow, ShouldBeFalse)
+		})
+	})
+}