1 files changed, 174 insertions, 0 deletions
diff --git a/internal/compress/flate/fuzz_test.go b/internal/compress/flate/fuzz_test.go
new file mode 100644
index 00000000..b97cd055
--- /dev/null
+++ b/internal/compress/flate/fuzz_test.go
@@ -0,0 +1,174 @@
+//go:build go1.18
+
+package flate
+
+import (
+	"bytes"
+	"flag"
+	"io"
+	"os"
+	"strconv"
+	"testing"
+
+	"codeberg.org/lindenii/furgit/internal/compress/internal/fuzz"
+)
+
+// Fuzzing tweaks:
+var fuzzStartF = flag.Int("start", HuffmanOnly, "Start fuzzing at this level")
+var fuzzEndF = flag.Int("end", BestCompression, "End fuzzing at this level (inclusive)")
+var fuzzMaxF = flag.Int("max", 1<<20, "Maximum input size")
+var fuzzSLF = flag.Bool("sl", true, "Include stateless encodes")
+var fuzzWindow = flag.Bool("windows", true, "Include windowed encodes")
+
+func TestMain(m *testing.M) {
+	flag.Parse()
+	os.Exit(m.Run())
+}
+
+func FuzzEncoding(f *testing.F) {
+	fuzz.AddFromZip(f, "testdata/regression.zip", fuzz.TypeRaw, false)
+	fuzz.AddFromZip(f, "testdata/fuzz/encode-raw-corpus.zip", fuzz.TypeRaw, testing.Short())
+	fuzz.AddFromZip(f, "testdata/fuzz/FuzzEncoding.zip", fuzz.TypeGoFuzz, testing.Short())
+
+	startFuzz := *fuzzStartF
+	endFuzz := *fuzzEndF
+	maxSize := *fuzzMaxF
+	stateless := *fuzzSLF
+	fuzzWindow := *fuzzWindow
+
+	decoder := NewReader(nil)
+	buf := new(bytes.Buffer)
+	encs := make([]*Writer, endFuzz-startFuzz+1)
+	for i := range encs {
+		var err error
+		encs[i], err = NewWriter(nil, i+startFuzz)
+		if err != nil {
+			f.Fatal(err.Error())
+		}
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		if len(data) > maxSize {
+			return
+		}
+		for level := startFuzz; level <= endFuzz; level++ {
+			msg := "level " + strconv.Itoa(level) + ":"
+			buf.Reset()
+			fw := encs[level-startFuzz]
+			fw.Reset(buf)
+			n, err := fw.Write(data)
+			if n != len(data) {
+				t.Fatal(msg + "short write")
+			}
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			err = fw.Close()
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			decoder.(Resetter).Reset(buf, nil)
+			data2, err := io.ReadAll(decoder)
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			if !bytes.Equal(data, data2) {
+				t.Fatal(msg + "not equal")
+			}
+			// Do it again... (also uses copy)
+			msg = "level " + strconv.Itoa(level) + " (reset):"
+			buf.Reset()
+			fw.Reset(buf)
+			_, err = io.Copy(fw, bytes.NewReader(data))
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			err = fw.Close()
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			decoder.(Resetter).Reset(buf, nil)
+			data2, err = io.ReadAll(decoder)
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			if !bytes.Equal(data, data2) {
+				t.Fatal(msg + "not equal")
+			}
+		}
+		if stateless {
+			// Split into two and use history...
+			msg := "stateless:"
+			buf.Reset()
+			err := StatelessDeflate(buf, data[:len(data)/2], false, nil)
+			if err != nil {
+				t.Error(err)
+			}
+
+			// Use top half as dictionary...
+			dict := data[:len(data)/2]
+			err = StatelessDeflate(buf, data[len(data)/2:], true, dict)
+			if err != nil {
+				t.Error(err)
+			}
+
+			decoder.(Resetter).Reset(buf, nil)
+			data2, err := io.ReadAll(decoder)
+			if err != nil {
+				t.Error(err)
+			}
+			if !bytes.Equal(data, data2) {
+				//fmt.Printf("want:%x\ngot: %x\n", data1, data2)
+				t.Error(msg + "not equal")
+			}
+		}
+		if fuzzWindow {
+			msg := "windowed:"
+			buf.Reset()
+			fw, err := NewWriterWindow(buf, 1000)
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			fw.Reset(buf)
+			n, err := fw.Write(data)
+			if n != len(data) {
+				t.Fatal(msg + "short write")
+			}
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			err = fw.Close()
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			decoder.(Resetter).Reset(buf, nil)
+			data2, err := io.ReadAll(decoder)
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			if !bytes.Equal(data, data2) {
+				t.Fatal(msg + "not equal")
+			}
+			// Do it again...
+			msg = msg + " (reset):"
+			buf.Reset()
+			fw.Reset(buf)
+			n, err = fw.Write(data)
+			if n != len(data) {
+				t.Fatal(msg + "short write")
+			}
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			err = fw.Close()
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+			decoder.(Resetter).Reset(buf, nil)
+			data2, err = io.ReadAll(decoder)
+			if err != nil {
+				t.Fatal(msg + err.Error())
+			}
+		}
+	})
+}