testing: move fuzzers over from OSS-Fuzz

Signed-off-by: AdamKorcz <adam@adalogics.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/tailfile/fuzz_test.go

@@ -0,0 +1,39 @@
+package tailfile
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	fuzz "github.com/AdaLogics/go-fuzz-headers"
+)
+
+func FuzzTailfile(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		if len(data) < 5 {
+			return
+		}
+		ff := fuzz.NewConsumer(data)
+		n, err := ff.GetUint64()
+		if err != nil {
+			return
+		}
+		fileBytes, err := ff.GetBytes()
+		if err != nil {
+			return
+		}
+		tempDir := t.TempDir()
+		fil, err := os.Create(filepath.Join(tempDir, "tailFile"))
+		if err != nil {
+			return
+		}
+		defer fil.Close()
+
+		_, err = fil.Write(fileBytes)
+		if err != nil {
+			return
+		}
+		fil.Seek(0, 0)
+		_, _ = TailFile(fil, int(n))
+	})
+}