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: parser_test.go
    path of file: ./repos/AdGuardHome/internal/filtering/rulelist
    
    the code of the file until where you have to start completion: package rulelist_test

import (
	"bufio"
	"bytes"
	"strings"
	"testing"

	"github.com/AdguardTeam/AdGuardHome/internal/filtering/rulelist"
	"github.com/AdguardTeam/golibs/errors"
	"github.com/AdguardTeam/golibs/testutil"
	"github.com/AdguardTeam/golibs/testutil/fakeio"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestParser_Parse(t *testing.T) {
	t.Parallel()

	longRule := strings.Repeat("a", rulelist.DefaultRuleBufSize+1) + "\n"
	tooLongRule := strings.Repeat("a", bufio.MaxScanTokenSize+1) + "\n"

	testCases := []struct {
		name         string
		in           string
		wantDst      string
		wantErrMsg   string
		want
    
func FuzzParser_Parse(f *testing.F) {
	const n = 64

	testCases := []string{
		"",
		"# Comment",
		"! Comment",
		"! Title ",
		"! Title XXX",
		testRuleTextBadTab,
		testRuleTextBlocked,
		testRuleTextCosmetic,
		testRuleTextEtcHostsTab,
		testRuleTextHTML,
		"1.2.3.4",
		"1.2.3.4 etc-hosts.example",
		">>>\x00<<<",
		">>>\x7F<<<",
		strings.Repeat("a", rulelist.DefaultRuleBufSize+1),
		strings.Repeat("a", bufio.MaxScanTokenSize+1),
	}

	for _, tc := range testCases {
		f.Add(tc)
	}

	buf := make([]byte, n)

	f.Fuzz(func(t *testing.T, input string) {
		require.Eventually(t, func() (ok bool) {
			dst := &bytes.Buffer{}
			src := strings.NewReader(input)

			p := rulelist.NewParser()
			r, _ := p.Parse(dst, src, buf)
			require.NotNil(t, r)

			return true
		}, testTimeout, testTimeout/100)
	})
}