add gofuzz test for consensus wal

consensus/wal_fuzz.go

@@ -0,0 +1,31 @@
+// +build gofuzz
+
+package consensus
+
+import (
+	"bytes"
+	"io"
+)
+
+func Fuzz(data []byte) int {
+	dec := NewWALDecoder(bytes.NewReader(data))
+	for {
+		msg, err := dec.Decode()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			if msg != nil {
+				panic("msg != nil on error")
+			}
+			return 0
+		}
+		var w bytes.Buffer
+		enc := NewWALEncoder(&w)
+		err = enc.Encode(msg)
+		if err != nil {
+			panic(err)
+		}
+	}
+	return 1
+}