Update fuzz to use new standard library support

bencode/fuzz.go

@@ -1,30 +0,0 @@
-//go:build gofuzz
-// +build gofuzz
-
-package bencode
-
-import (
-	"fmt"
-	"reflect"
-)
-
-func Fuzz(b []byte) int {
-	var d interface{}
-	err := Unmarshal(b, &d)
-	if err != nil {
-		return 0
-	}
-	b0, err := Marshal(d)
-	if err != nil {
-		panic(err)
-	}
-	var d0 interface{}
-	err = Unmarshal(b0, &d0)
-	if err != nil {
-		panic(err)
-	}
-	if !reflect.DeepEqual(d, d0) {
-		panic(fmt.Sprintf("%s != %s", d, d0))
-	}
-	return 1
-}

bencode/fuzz_test.go

@@ -0,0 +1,26 @@
+//go:build go1.18
+
+package bencode
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func Fuzz(f *testing.F) {
+	f.Fuzz(func(t *testing.T, b []byte) {
+		c := qt.New(t)
+		var d interface{}
+		err := Unmarshal(b, &d)
+		if err != nil {
+			t.Skip()
+		}
+		b0, err := Marshal(d)
+		c.Assert(err, qt.IsNil)
+		var d0 interface{}
+		err = Unmarshal(b0, &d0)
+		c.Assert(err, qt.IsNil)
+		c.Assert(d0, qt.DeepEquals, d)
+	})
+}

metainfo/fuzz.go

@@ -1,29 +0,0 @@
-//go:build gofuzz
-// +build gofuzz
-
-package metainfo
-
-import (
-	"github.com/anacrolix/torrent/bencode"
-)
-
-func Fuzz(b []byte) int {
-	var mi MetaInfo
-	err := bencode.Unmarshal(b, &mi)
-	if err != nil {
-		return 0
-	}
-	_, err = bencode.Marshal(mi)
-	if err != nil {
-		panic(err)
-	}
-	info, err := mi.UnmarshalInfo()
-	if err != nil {
-		return 0
-	}
-	_, err = bencode.Marshal(info)
-	if err != nil {
-		panic(err)
-	}
-	return 1
-}

metainfo/fuzz_test.go

@@ -0,0 +1,46 @@
+//go:build go1.18
+
+package metainfo
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/anacrolix/torrent/bencode"
+)
+
+func Fuzz(f *testing.F) {
+	// Is there an OS-agnostic version of Glob?
+	matches, err := filepath.Glob(filepath.FromSlash("testdata/*.torrent"))
+	if err != nil {
+		f.Fatal(err)
+	}
+	for _, m := range matches {
+		b, err := os.ReadFile(m)
+		if err != nil {
+			f.Fatal(err)
+		}
+		f.Logf("adding %q", m)
+		f.Add(b)
+	}
+	f.Fuzz(func(t *testing.T, b []byte) {
+		var mi MetaInfo
+		err := bencode.Unmarshal(b, &mi)
+		if err != nil {
+			t.Skip(err)
+		}
+		_, err = bencode.Marshal(mi)
+		if err != nil {
+			panic(err)
+		}
+		info, err := mi.UnmarshalInfo()
+		if err != nil {
+			t.Skip(err)
+		}
+		_, err = bencode.Marshal(info)
+		if err != nil {
+			panic(err)
+		}
+	})
+}