pkg/osutil: add tar.gz generation helpers

1 files changed, 60 insertions, 0 deletions

diff --git a/pkg/osutil/tar_test.go b/pkg/osutil/tar_test.go
new file mode 100644
index 000000000..a0e5a22bd
--- /dev/null
+++ b/pkg/osutil/tar_test.go
@@ -0,0 +1,60 @@
+// Copyright 2025 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package osutil
+
+import (
+	"archive/tar"
+	"bytes"
+	"io"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTarDirectory(t *testing.T) {
+	dir := t.TempDir()
+
+	items := map[string]string{
+		"file1.txt":     "first file content",
+		"dir/file2.txt": "second file content",
+		"empty.txt":     "",
+	}
+
+	for path, content := range items {
+		fullPath := filepath.Join(dir, path)
+		dirPath := filepath.Dir(fullPath)
+		if err := MkdirAll(dirPath); err != nil {
+			t.Fatalf("mkdir %q failed: %v", dirPath, err)
+		}
+		if err := WriteFile(fullPath, []byte(content)); err != nil {
+			t.Fatalf("write file failed: %v", err)
+		}
+	}
+
+	var buf bytes.Buffer
+	err := tarDirectory(dir, &buf)
+	assert.NoError(t, err)
+
+	tr := tar.NewReader(&buf)
+	found := make(map[string]string)
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+		if hdr.Typeflag == tar.TypeReg {
+			contentBytes, err := io.ReadAll(tr)
+			if err != nil {
+				t.Fatal(err)
+			}
+			found[hdr.Name] = string(contentBytes)
+		}
+	}
+
+	assert.Equal(t, items, found)
+}