feat: add multi directories support (#335)

lib/multidir_test.go

@@ -0,0 +1,72 @@
+package lib
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRenameAcrossMount(t *testing.T) {
+	source := makeTestDirectory(t, map[string][]byte{
+		"file.txt":               []byte("cross mount"),
+		"folder/empty":           nil,
+		"folder/nested/file.txt": []byte("nested"),
+	})
+	target := t.TempDir()
+	sourceFile := filepath.Join(source, "file.txt")
+	modTime := time.Date(2020, time.January, 2, 3, 4, 5, 0, time.UTC)
+	require.NoError(t, os.Chmod(sourceFile, 0600))
+	require.NoError(t, os.Chtimes(sourceFile, modTime, modTime))
+
+	require.NoError(t, renameAcrossMount(sourceFile, filepath.Join(target, "file.txt")))
+	require.NoFileExists(t, filepath.Join(source, "file.txt"))
+	data, err := os.ReadFile(filepath.Join(target, "file.txt"))
+	require.NoError(t, err)
+	require.Equal(t, []byte("cross mount"), data)
+	info, err := os.Stat(filepath.Join(target, "file.txt"))
+	require.NoError(t, err)
+	if runtime.GOOS != "windows" {
+		require.Equal(t, os.FileMode(0600), info.Mode().Perm())
+	}
+	require.WithinDuration(t, modTime, info.ModTime(), time.Second)
+
+	require.NoError(t, renameAcrossMount(filepath.Join(source, "folder"), filepath.Join(target, "folder")))
+	require.NoDirExists(t, filepath.Join(source, "folder"))
+	require.DirExists(t, filepath.Join(target, "folder", "empty"))
+	data, err = os.ReadFile(filepath.Join(target, "folder", "nested", "file.txt"))
+	require.NoError(t, err)
+	require.Equal(t, []byte("nested"), data)
+}
+
+func TestRenameAcrossMountPreservesSymlink(t *testing.T) {
+	source := makeTestDirectory(t, map[string][]byte{
+		"file.txt": []byte("target"),
+	})
+	oldPath := filepath.Join(source, "link.txt")
+	if err := os.Symlink("file.txt", oldPath); err != nil {
+		t.Skipf("symbolic links are unavailable: %v", err)
+	}
+	newPath := filepath.Join(t.TempDir(), "link.txt")
+
+	require.NoError(t, renameAcrossMount(oldPath, newPath))
+	info, err := os.Lstat(newPath)
+	require.NoError(t, err)
+	require.NotZero(t, info.Mode()&os.ModeSymlink)
+	target, err := os.Readlink(newPath)
+	require.NoError(t, err)
+	require.Equal(t, "file.txt", target)
+}
+
+func TestIsCrossDeviceError(t *testing.T) {
+	err := syscall.EXDEV
+	if runtime.GOOS == "windows" {
+		err = windowsErrorNotSameDevice
+	}
+	require.True(t, isCrossDeviceError(err))
+	require.False(t, isCrossDeviceError(os.ErrPermission))
+}