From bd892775f6816326f933e158f5549f6cf9de86b1 Mon Sep 17 00:00:00 2001
From: "Lixia (Sylvia) Lei" <lixlei@microsoft.com>
Date: Mon, 13 Jan 2025 17:23:54 +0800
Subject: [PATCH] test linux

---
 content/file/utils_unix_test.go | 143 ++++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 content/file/utils_unix_test.go

diff --git a/content/file/utils_unix_test.go b/content/file/utils_unix_test.go
new file mode 100644
index 00000000..ede6c167
--- /dev/null
+++ b/content/file/utils_unix_test.go
@@ -0,0 +1,143 @@
+//go:build !windows
+
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package file
+
+import (
+	"archive/tar"
+	"bytes"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func Test_extractTarDirectory(t *testing.T) {
+	tests := []struct {
+		name      string
+		tarData   []byte
+		wantFiles map[string]string // map of file paths to their expected contents
+		wantErr   bool
+	}{
+		{
+			name: "extract valid files",
+			tarData: createTar(t, []tarEntry{
+				{name: "base/", mode: os.ModeDir},
+				{name: "base/test.txt", content: "hello world"},
+				{name: "base/file_symlink", linkname: "test.txt", mode: os.ModeSymlink},
+				{name: "base/file_hardlink", linkname: "test.txt", isHardLink: true},
+			}),
+			wantFiles: map[string]string{
+				"base/test.txt":      "hello world",
+				"base/file_symlink":  "hello world",
+				"base/file_hardlink": "hello world",
+			},
+			wantErr: false,
+		},
+		{
+			name: "non-regular files",
+			tarData: createTar(t, []tarEntry{
+				{name: "something", isNonRegular: true},
+			}),
+			wantErr: true,
+		},
+		{
+			name:    "invalid tar header",
+			tarData: []byte("random data"),
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tempDir := t.TempDir()
+			dirName := "base"
+			dirPath := filepath.Join(tempDir, dirName)
+			buf := make([]byte, 1024)
+
+			if err := extractTarDirectory(dirPath, dirName, bytes.NewReader(tt.tarData), buf); (err != nil) != tt.wantErr {
+				t.Fatalf("extractTarDirectory() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			if !tt.wantErr {
+				for path, wantContent := range tt.wantFiles {
+					filePath := filepath.Join(tempDir, path)
+					fi, err := os.Lstat(filePath)
+					if err != nil {
+						t.Fatalf("failed to stat file %s: %v", filePath, err)
+					}
+
+					if fi.Mode()&os.ModeSymlink != 0 {
+						filePath, err = os.Readlink(filePath)
+						if err != nil {
+							t.Fatalf("failed to read link %s: %v", filePath, err)
+						}
+						if !filepath.IsAbs(filePath) {
+							filePath = filepath.Join(tempDir, filePath)
+						}
+					}
+					gotContent, err := os.ReadFile(filePath)
+					if err != nil {
+						t.Fatalf("failed to read file %s: %v", filePath, err)
+					}
+					if string(gotContent) != wantContent {
+						t.Errorf("file content = %s, want %s", gotContent, wantContent)
+					}
+				}
+			}
+		})
+	}
+}
+
+type tarEntry struct {
+	name         string
+	content      string
+	linkname     string
+	mode         os.FileMode
+	isNonRegular bool
+	isHardLink   bool
+}
+
+func createTar(t *testing.T, entries []tarEntry) []byte {
+	var buf bytes.Buffer
+	tw := tar.NewWriter(&buf)
+
+	for _, entry := range entries {
+		hdr := &tar.Header{
+			Name: entry.name,
+			Mode: int64(entry.mode),
+			Size: int64(len(entry.content)),
+		}
+		if entry.isNonRegular {
+			hdr.Typeflag = tar.TypeBlock
+		} else if entry.isHardLink {
+			hdr.Typeflag = tar.TypeLink
+			hdr.Linkname = entry.linkname
+		} else if entry.mode&os.ModeSymlink != 0 {
+			hdr.Typeflag = tar.TypeSymlink
+			hdr.Linkname = entry.linkname
+		}
+
+		if err := tw.WriteHeader(hdr); err != nil {
+			t.Fatalf("failed to write tar header: %v", err)
+		}
+		if _, err := tw.Write([]byte(entry.content)); err != nil {
+			t.Fatalf("failed to write tar content: %v", err)
+		}
+	}
+
+	if err := tw.Close(); err != nil {
+		t.Fatalf("failed to close tar writer: %v", err)
+	}
+	return buf.Bytes()
+}