common,crypto: move fuzzers out of core (#22029)

* common,crypto: move fuzzers out of core

* fuzzers: move vm fuzzer out from core

* fuzzing: rework cover package logic

* fuzzers: lint

tests/fuzzers/bitutil/compress_fuzz.go

@@ -0,0 +1,58 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bitutil
+
+import (
+	"bytes"
+
+	"github.com/ethereum/go-ethereum/common/bitutil"
+)
+
+// Fuzz implements a go-fuzz fuzzer method to test various encoding method
+// invocations.
+func Fuzz(data []byte) int {
+	if len(data) == 0 {
+		return 0
+	}
+	if data[0]%2 == 0 {
+		return fuzzEncode(data[1:])
+	}
+	return fuzzDecode(data[1:])
+}
+
+// fuzzEncode implements a go-fuzz fuzzer method to test the bitset encoding and
+// decoding algorithm.
+func fuzzEncode(data []byte) int {
+	proc, _ := bitutil.DecompressBytes(bitutil.CompressBytes(data), len(data))
+	if !bytes.Equal(data, proc) {
+		panic("content mismatch")
+	}
+	return 1
+}
+
+// fuzzDecode implements a go-fuzz fuzzer method to test the bit decoding and
+// reencoding algorithm.
+func fuzzDecode(data []byte) int {
+	blob, err := bitutil.DecompressBytes(data, 1024)
+	if err != nil {
+		return 0
+	}
+	if comp := bitutil.CompressBytes(blob); !bytes.Equal(comp, data) {
+		panic("content mismatch")
+	}
+	return 1
+}