You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: util_test.go
    path of file: ./repos/syncthing/lib/fs
    
    the code of the file until where you have to start completion: // Copyright (C) 2019 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.

package fs

import (
	"errors"
	"math/rand"
	"testing"
	"unicode"
	"unicode/utf8"

	"github.com/syncthing/syncthing/lib/build"
)

func TestCommonPrefix(t *testing.T) {
	test := func(first, second, expect string) {
		t.Helpe
    
func TestSanitizePath(t *testing.T) {
	cases := [][2]string{
		{"", ""},
		{"foo", "foo"},
		{`\*/foo\?/bar[{!@$%^&*#()}]`, "foo bar ()"},
		{"Räksmörgås", "Räksmörgås"},
		{`Räk \/ smörgås`, "Räk smörgås"},
		{"هذا هو *\x07?اسم الملف", "هذا هو اسم الملف"},
		{`../foo.txt`, `.. foo.txt`},
		{"  \t \n filename in  \t space\r", "filename in space"},
		{"你\xff好", `你 好`},
		{"\000 foo", "foo"},
	}

	for _, tc := range cases {
		res := SanitizePath(tc[0])
		if res != tc[1] {
			t.Errorf("SanitizePath(%q) => %q, expected %q", tc[0], res, tc[1])
		}
	}
}