Return `fs.ModeDir` for Git folders in the workspace (#1521)

## Changes

Not doing this meant file system traversal ended upon reaching a Git
folder. By marking these objects as a directory globbing traverses into
these folders as well.

## Tests

Added a unit test for coverage.

libs/filer/workspace_files_client.go

@@ -35,6 +35,17 @@ func (entry wsfsDirEntry) Info() (fs.FileInfo, error) {
 	return entry.wsfsFileInfo, nil
 }
 
+func wsfsDirEntriesFromObjectInfos(objects []workspace.ObjectInfo) []fs.DirEntry {
+	info := make([]fs.DirEntry, len(objects))
+	for i, v := range objects {
+		info[i] = wsfsDirEntry{wsfsFileInfo{oi: v}}
+	}
+
+	// Sort by name for parity with os.ReadDir.
+	sort.Slice(info, func(i, j int) bool { return info[i].Name() < info[j].Name() })
+	return info
+}
+
 // Type that implements fs.FileInfo for WSFS.
 type wsfsFileInfo struct {
 	oi workspace.ObjectInfo
@@ -50,7 +61,7 @@ func (info wsfsFileInfo) Size() int64 {
 
 func (info wsfsFileInfo) Mode() fs.FileMode {
 	switch info.oi.ObjectType {
-	case workspace.ObjectTypeDirectory:
+	case workspace.ObjectTypeDirectory, workspace.ObjectTypeRepo:
 		return fs.ModeDir
 	default:
 		return fs.ModePerm
@@ -62,7 +73,7 @@ func (info wsfsFileInfo) ModTime() time.Time {
 }
 
 func (info wsfsFileInfo) IsDir() bool {
-	return info.oi.ObjectType == workspace.ObjectTypeDirectory
+	return info.Mode() == fs.ModeDir
 }
 
 func (info wsfsFileInfo) Sys() any {
@@ -262,14 +273,8 @@ func (w *WorkspaceFilesClient) ReadDir(ctx context.Context, name string) ([]fs.D
 		return nil, err
 	}
 
-	info := make([]fs.DirEntry, len(objects))
-	for i, v := range objects {
-		info[i] = wsfsDirEntry{wsfsFileInfo{oi: v}}
-	}
-
-	// Sort by name for parity with os.ReadDir.
-	sort.Slice(info, func(i, j int) bool { return info[i].Name() < info[j].Name() })
-	return info, nil
+	// Convert to fs.DirEntry.
+	return wsfsDirEntriesFromObjectInfos(objects), nil
 }
 
 func (w *WorkspaceFilesClient) Mkdir(ctx context.Context, name string) error {

libs/filer/workspace_files_client_test.go

@@ -0,0 +1,56 @@
+package filer
+
+import (
+	"io/fs"
+	"testing"
+
+	"github.com/databricks/databricks-sdk-go/service/workspace"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWorkspaceFilesDirEntry(t *testing.T) {
+	entries := wsfsDirEntriesFromObjectInfos([]workspace.ObjectInfo{
+		{
+			Path:       "/dir",
+			ObjectType: workspace.ObjectTypeDirectory,
+		},
+		{
+			Path:       "/file",
+			ObjectType: workspace.ObjectTypeFile,
+			Size:       42,
+		},
+		{
+			Path:       "/repo",
+			ObjectType: workspace.ObjectTypeRepo,
+		},
+	})
+
+	// Confirm the path is passed through correctly.
+	assert.Equal(t, "dir", entries[0].Name())
+	assert.Equal(t, "file", entries[1].Name())
+	assert.Equal(t, "repo", entries[2].Name())
+
+	// Confirm the type is passed through correctly.
+	assert.Equal(t, fs.ModeDir, entries[0].Type())
+	assert.Equal(t, fs.ModePerm, entries[1].Type())
+	assert.Equal(t, fs.ModeDir, entries[2].Type())
+
+	// Get [fs.FileInfo] from directory entry.
+	i0, err := entries[0].Info()
+	require.NoError(t, err)
+	i1, err := entries[1].Info()
+	require.NoError(t, err)
+	i2, err := entries[2].Info()
+	require.NoError(t, err)
+
+	// Confirm size.
+	assert.Equal(t, int64(0), i0.Size())
+	assert.Equal(t, int64(42), i1.Size())
+	assert.Equal(t, int64(0), i2.Size())
+
+	// Confirm IsDir.
+	assert.True(t, i0.IsDir())
+	assert.False(t, i1.IsDir())
+	assert.True(t, i2.IsDir())
+}