Refactor a bit.

service/rawdatastore/invertible_test.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 rawdatastore
+
+import (
+        "bytes"
+        "testing"
+
+        . "github.com/smartystreets/goconvey/convey"
+)
+
+func TestInvertible(t *testing.T) {
+        t.Parallel()
+
+        Convey("Test InvertibleByteBuffer", t, func() {
+                inv := Invertible(&bytes.Buffer{})
+
+                Convey("normal writing", func() {
+                        Convey("Write", func() {
+                                n, err := inv.Write([]byte("hello"))
+                                So(err, ShouldBeNil)
+                                So(n, ShouldEqual, 5)
+                                So(inv.String(), ShouldEqual, "hello")
+                        })
+                        Convey("WriteString", func() {
+                                n, err := inv.WriteString("hello")
+                                So(err, ShouldBeNil)
+                                So(n, ShouldEqual, 5)
+                                So(inv.String(), ShouldEqual, "hello")
+                        })
+                        Convey("WriteByte", func() {
+                                for i := byte('a'); i < 'f'; i++ {
+                                        err := inv.WriteByte(i)
+                                        So(err, ShouldBeNil)
+                                }
+                                So(inv.String(), ShouldEqual, "abcde")
+
+                                Convey("ReadByte", func() {
+                                        for i := 0; i < 5; i++ {
+                                                b, err := inv.ReadByte()
+                                                So(err, ShouldBeNil)
+                                                So(b, ShouldEqual, byte('a')+byte(i))
+                                        }
+                                })
+                        })
+                })
+                Convey("inverted writing", func() {
+                        inv.Invert()
+                        Convey("Write", func() {
+                                n, err := inv.Write([]byte("hello"))
+                                So(err, ShouldBeNil)
+                                So(n, ShouldEqual, 5)
+                                So(inv.String(), ShouldEqual, "\x97\x9a\x93\x93\x90")
+                        })
+                        Convey("WriteString", func() {
+                                n, err := inv.WriteString("hello")
+                                So(err, ShouldBeNil)
+                                So(n, ShouldEqual, 5)
+                                So(inv.String(), ShouldEqual, "\x97\x9a\x93\x93\x90")
+                        })
+                        Convey("WriteByte", func() {
+                                for i := byte('a'); i < 'f'; i++ {
+                                        err := inv.WriteByte(i)
+                                        So(err, ShouldBeNil)
+                                }
+                                So(inv.String(), ShouldEqual, "\x9e\x9d\x9c\x9b\x9a")
+
+                                Convey("ReadByte", func() {
+                                        for i := 0; i < 5; i++ {
+                                                b, err := inv.ReadByte()
+                                                So(err, ShouldBeNil)
+                                                So(b, ShouldEqual, byte('a')+byte(i)) // inverted back to normal
+                                        }
+                                })
+                        })
+                })
+                Convey("Toggleable", func() {
+                        inv.Invert()
+                        n, err := inv.Write([]byte("hello"))
+                        So(err, ShouldBeNil)
+                        inv.Invert()
+                        n, err = inv.Write([]byte("hello"))
+                        So(n, ShouldEqual, 5)
+                        So(inv.String(), ShouldEqual, "\x97\x9a\x93\x93\x90hello")
+                })
+        })
+}