Make local files default for fs commands (#506)

## Changes
<!-- Summary of your changes that are easy to understand -->

## Tests
<!-- How is this tested? -->

cmd/fs/helpers.go

@@ -10,47 +10,38 @@ import (
 	"github.com/databricks/cli/libs/filer"
 )
 
-type Scheme string
-
-const (
-	DbfsScheme  = Scheme("dbfs")
-	LocalScheme = Scheme("file")
-	NoScheme    = Scheme("")
-)
-
 func filerForPath(ctx context.Context, fullPath string) (filer.Filer, string, error) {
-	parts := strings.SplitN(fullPath, ":/", 2)
+	// Split path at : to detect any file schemes
+	parts := strings.SplitN(fullPath, ":", 2)
+
+	// If no scheme is specified, then local path
 	if len(parts) < 2 {
-		return nil, "", fmt.Errorf(`no scheme specified for path %s. Please specify scheme "dbfs" or "file". Example: file:/foo/bar or file:/c:/foo/bar`, fullPath)
+		f, err := filer.NewLocalClient("")
+		return f, fullPath, err
 	}
-	scheme := Scheme(parts[0])
+
+	// On windows systems, paths start with a drive letter. If the scheme
+	// is a single letter and the OS is windows, then we conclude the path
+	// is meant to be a local path.
+	if runtime.GOOS == "windows" && len(parts[0]) == 1 {
+		f, err := filer.NewLocalClient("")
+		return f, fullPath, err
+	}
+
+	if parts[0] != "dbfs" {
+		return nil, "", fmt.Errorf("invalid scheme: %s", parts[0])
+	}
+
 	path := parts[1]
-	switch scheme {
-	case DbfsScheme:
-		w := root.WorkspaceClient(ctx)
-		// If the specified path has the "Volumes" prefix, use the Files API.
-		if strings.HasPrefix(path, "Volumes/") {
-			f, err := filer.NewFilesClient(w, "/")
-			return f, path, err
-		}
-		f, err := filer.NewDbfsClient(w, "/")
-		return f, path, err
+	w := root.WorkspaceClient(ctx)
 
-	case LocalScheme:
-		if runtime.GOOS == "windows" {
-			parts := strings.SplitN(path, ":", 2)
-			if len(parts) < 2 {
-				return nil, "", fmt.Errorf("no volume specfied for path: %s", path)
-			}
-			volume := parts[0] + ":"
-			relPath := parts[1]
-			f, err := filer.NewLocalClient(volume)
-			return f, relPath, err
-		}
-		f, err := filer.NewLocalClient("/")
+	// If the specified path has the "Volumes" prefix, use the Files API.
+	if strings.HasPrefix(path, "/Volumes/") {
+		f, err := filer.NewFilesClient(w, "/")
 		return f, path, err
-
-	default:
-		return nil, "", fmt.Errorf(`unsupported scheme %s specified for path %s. Please specify scheme "dbfs" or "file". Example: file:/foo/bar or file:/c:/foo/bar`, scheme, fullPath)
 	}
+
+	// The file is a dbfs file, and uses the DBFS APIs
+	f, err := filer.NewDbfsClient(w, "/")
+	return f, path, err
 }

cmd/fs/helpers_test.go

@@ -5,22 +5,58 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/databricks/cli/libs/filer"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
-func TestNotSpecifyingVolumeForWindowsPathErrors(t *testing.T) {
+func TestFilerForPathForLocalPaths(t *testing.T) {
+	tmpDir := t.TempDir()
+	ctx := context.Background()
+
+	f, path, err := filerForPath(ctx, tmpDir)
+	assert.NoError(t, err)
+	assert.Equal(t, tmpDir, path)
+
+	info, err := f.Stat(ctx, path)
+	require.NoError(t, err)
+	assert.True(t, info.IsDir())
+}
+
+func TestFilerForPathForInvalidScheme(t *testing.T) {
+	ctx := context.Background()
+
+	_, _, err := filerForPath(ctx, "dbf:/a")
+	assert.ErrorContains(t, err, "invalid scheme")
+
+	_, _, err = filerForPath(ctx, "foo:a")
+	assert.ErrorContains(t, err, "invalid scheme")
+
+	_, _, err = filerForPath(ctx, "file:/a")
+	assert.ErrorContains(t, err, "invalid scheme")
+}
+
+func testWindowsFilerForPath(t *testing.T, ctx context.Context, fullPath string) {
+	f, path, err := filerForPath(ctx, fullPath)
+	assert.NoError(t, err)
+
+	// Assert path remains unchanged
+	assert.Equal(t, path, fullPath)
+
+	// Assert local client is created
+	_, ok := f.(*filer.LocalClient)
+	assert.True(t, ok)
+}
+
+func TestFilerForWindowsLocalPaths(t *testing.T) {
 	if runtime.GOOS != "windows" {
-		t.Skip()
+		t.SkipNow()
 	}
 
 	ctx := context.Background()
-	pathWithVolume := `file:/c:/foo/bar`
-	pathWOVolume := `file:/uno/dos`
-
-	_, path, err := filerForPath(ctx, pathWithVolume)
-	assert.NoError(t, err)
-	assert.Equal(t, `/foo/bar`, path)
-
-	_, _, err = filerForPath(ctx, pathWOVolume)
-	assert.Equal(t, "no volume specfied for path: uno/dos", err.Error())
+	testWindowsFilerForPath(t, ctx, `c:\abc`)
+	testWindowsFilerForPath(t, ctx, `c:abc`)
+	testWindowsFilerForPath(t, ctx, `d:\abc`)
+	testWindowsFilerForPath(t, ctx, `d:\abc`)
+	testWindowsFilerForPath(t, ctx, `f:\abc\ef`)
 }

internal/fs_cp_test.go

@@ -66,7 +66,7 @@ func setupLocalFiler(t *testing.T) (filer.Filer, string) {
 	f, err := filer.NewLocalClient(tmp)
 	require.NoError(t, err)
 
-	return f, path.Join("file:/", filepath.ToSlash(tmp))
+	return f, path.Join(filepath.ToSlash(tmp))
 }
 
 func setupDbfsFiler(t *testing.T) (filer.Filer, string) {
@@ -259,21 +259,14 @@ func TestAccFsCpErrorsWhenSourceIsDirWithoutRecursiveFlag(t *testing.T) {
 	tmpDir := temporaryDbfsDir(t, w)
 
 	_, _, err = RequireErrorRun(t, "fs", "cp", "dbfs:"+tmpDir, "dbfs:/tmp")
-	assert.Equal(t, fmt.Sprintf("source path %s is a directory. Please specify the --recursive flag", strings.TrimPrefix(tmpDir, "/")), err.Error())
-}
-
-func TestAccFsCpErrorsOnNoScheme(t *testing.T) {
-	t.Log(GetEnvOrSkipTest(t, "CLOUD_ENV"))
-
-	_, _, err := RequireErrorRun(t, "fs", "cp", "/a", "/b")
-	assert.Equal(t, "no scheme specified for path /a. Please specify scheme \"dbfs\" or \"file\". Example: file:/foo/bar or file:/c:/foo/bar", err.Error())
+	assert.Equal(t, fmt.Sprintf("source path %s is a directory. Please specify the --recursive flag", tmpDir), err.Error())
 }
 
 func TestAccFsCpErrorsOnInvalidScheme(t *testing.T) {
 	t.Log(GetEnvOrSkipTest(t, "CLOUD_ENV"))
 
 	_, _, err := RequireErrorRun(t, "fs", "cp", "dbfs:/a", "https:/b")
-	assert.Equal(t, "unsupported scheme https specified for path https:/b. Please specify scheme \"dbfs\" or \"file\". Example: file:/foo/bar or file:/c:/foo/bar", err.Error())
+	assert.Equal(t, "invalid scheme: https", err.Error())
 }
 
 func TestAccFsCpSourceIsDirectoryButTargetIsFile(t *testing.T) {

libs/filer/dbfs_client.go

@@ -68,14 +68,14 @@ type DbfsClient struct {
 	workspaceClient *databricks.WorkspaceClient
 
 	// File operations will be relative to this path.
-	root RootPath
+	root WorkspaceRootPath
 }
 
 func NewDbfsClient(w *databricks.WorkspaceClient, root string) (Filer, error) {
 	return &DbfsClient{
 		workspaceClient: w,
 
-		root: NewRootPath(root),
+		root: NewWorkspaceRootPath(root),
 	}, nil
 }
 

libs/filer/files_client.go

@@ -60,7 +60,7 @@ type FilesClient struct {
 	apiClient       *client.DatabricksClient
 
 	// File operations will be relative to this path.
-	root RootPath
+	root WorkspaceRootPath
 }
 
 func filesNotImplementedError(fn string) error {
@@ -77,7 +77,7 @@ func NewFilesClient(w *databricks.WorkspaceClient, root string) (Filer, error) {
 		workspaceClient: w,
 		apiClient:       apiClient,
 
-		root: NewRootPath(root),
+		root: NewWorkspaceRootPath(root),
 	}, nil
 }
 

libs/filer/local_client.go

@@ -13,12 +13,12 @@ import (
 // LocalClient implements the [Filer] interface for the local filesystem.
 type LocalClient struct {
 	// File operations will be relative to this path.
-	root RootPath
+	root localRootPath
 }
 
 func NewLocalClient(root string) (Filer, error) {
 	return &LocalClient{
-		root: NewRootPath(root),
+		root: NewLocalRootPath(root),
 	}, nil
 }
 

libs/filer/local_root_path.go

@@ -0,0 +1,27 @@
+package filer
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+)
+
+type localRootPath struct {
+	rootPath string
+}
+
+func NewLocalRootPath(root string) localRootPath {
+	if root == "" {
+		return localRootPath{""}
+	}
+	return localRootPath{filepath.Clean(root)}
+}
+
+func (rp *localRootPath) Join(name string) (string, error) {
+	absPath := filepath.Join(rp.rootPath, name)
+
+	if !strings.HasPrefix(absPath, rp.rootPath) {
+		return "", fmt.Errorf("relative path escapes root: %s", name)
+	}
+	return absPath, nil
+}

libs/filer/local_root_path_test.go

@@ -0,0 +1,142 @@
+package filer
+
+import (
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func testUnixLocalRootPath(t *testing.T, uncleanRoot string) {
+	cleanRoot := filepath.Clean(uncleanRoot)
+	rp := NewLocalRootPath(uncleanRoot)
+
+	remotePath, err := rp.Join("a/b/c")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+"/a/b/c", remotePath)
+
+	remotePath, err = rp.Join("a/b/../d")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+"/a/d", remotePath)
+
+	remotePath, err = rp.Join("a/../c")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+"/c", remotePath)
+
+	remotePath, err = rp.Join("a/b/c/.")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+"/a/b/c", remotePath)
+
+	remotePath, err = rp.Join("a/b/c/d/./../../f/g")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+"/a/b/f/g", remotePath)
+
+	remotePath, err = rp.Join(".//a/..//./b/..")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	remotePath, err = rp.Join("a/b/../..")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	remotePath, err = rp.Join("")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	remotePath, err = rp.Join(".")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	remotePath, err = rp.Join("/")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	_, err = rp.Join("..")
+	assert.ErrorContains(t, err, `relative path escapes root: ..`)
+
+	_, err = rp.Join("a/../..")
+	assert.ErrorContains(t, err, `relative path escapes root: a/../..`)
+
+	_, err = rp.Join("./../.")
+	assert.ErrorContains(t, err, `relative path escapes root: ./../.`)
+
+	_, err = rp.Join("/./.././..")
+	assert.ErrorContains(t, err, `relative path escapes root: /./.././..`)
+
+	_, err = rp.Join("./../.")
+	assert.ErrorContains(t, err, `relative path escapes root: ./../.`)
+
+	_, err = rp.Join("./..")
+	assert.ErrorContains(t, err, `relative path escapes root: ./..`)
+
+	_, err = rp.Join("./../../..")
+	assert.ErrorContains(t, err, `relative path escapes root: ./../../..`)
+
+	_, err = rp.Join("./../a/./b../../..")
+	assert.ErrorContains(t, err, `relative path escapes root: ./../a/./b../../..`)
+
+	_, err = rp.Join("../..")
+	assert.ErrorContains(t, err, `relative path escapes root: ../..`)
+}
+
+func TestUnixLocalRootPath(t *testing.T) {
+	if runtime.GOOS != "darwin" && runtime.GOOS != "linux" {
+		t.SkipNow()
+	}
+
+	testUnixLocalRootPath(t, "/some/root/path")
+	testUnixLocalRootPath(t, "/some/root/path/")
+	testUnixLocalRootPath(t, "/some/root/path/.")
+	testUnixLocalRootPath(t, "/some/root/../path/")
+}
+
+func testWindowsLocalRootPath(t *testing.T, uncleanRoot string) {
+	cleanRoot := filepath.Clean(uncleanRoot)
+	rp := NewLocalRootPath(uncleanRoot)
+
+	remotePath, err := rp.Join(`a\b\c`)
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+`\a\b\c`, remotePath)
+
+	remotePath, err = rp.Join(`a\b\..\d`)
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+`\a\d`, remotePath)
+
+	remotePath, err = rp.Join(`a\..\c`)
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+`\c`, remotePath)
+
+	remotePath, err = rp.Join(`a\b\c\.`)
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot+`\a\b\c`, remotePath)
+
+	remotePath, err = rp.Join(`a\b\..\..`)
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	remotePath, err = rp.Join("")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	remotePath, err = rp.Join(".")
+	assert.NoError(t, err)
+	assert.Equal(t, cleanRoot, remotePath)
+
+	_, err = rp.Join("..")
+	assert.ErrorContains(t, err, `relative path escapes root`)
+
+	_, err = rp.Join(`a\..\..`)
+	assert.ErrorContains(t, err, `relative path escapes root`)
+}
+
+func TestWindowsLocalRootPath(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		t.SkipNow()
+	}
+
+	testWindowsLocalRootPath(t, `c:\some\root\path`)
+	testWindowsLocalRootPath(t, `c:\some\root\path\`)
+	testWindowsLocalRootPath(t, `c:\some\root\path\.`)
+	testWindowsLocalRootPath(t, `C:\some\root\..\path\`)
+}

libs/filer/workspace_files_client.go

@@ -78,7 +78,7 @@ type WorkspaceFilesClient struct {
 	apiClient       *client.DatabricksClient
 
 	// File operations will be relative to this path.
-	root RootPath
+	root WorkspaceRootPath
 }
 
 func NewWorkspaceFilesClient(w *databricks.WorkspaceClient, root string) (Filer, error) {
@@ -91,7 +91,7 @@ func NewWorkspaceFilesClient(w *databricks.WorkspaceClient, root string) (Filer,
 		workspaceClient: w,
 		apiClient:       apiClient,
 
-		root: NewRootPath(root),
+		root: NewWorkspaceRootPath(root),
 	}, nil
 }
 

libs/filer/workspace_root_path.go

@@ -6,23 +6,23 @@ import (
 	"strings"
 )
 
-// RootPath can be joined with a relative path and ensures that
+// WorkspaceRootPath can be joined with a relative path and ensures that
 // the returned path is always a strict child of the root path.
-type RootPath struct {
+type WorkspaceRootPath struct {
 	rootPath string
 }
 
-// NewRootPath constructs and returns [RootPath].
+// NewWorkspaceRootPath constructs and returns [RootPath].
 // The named path is cleaned on construction.
-func NewRootPath(name string) RootPath {
-	return RootPath{
+func NewWorkspaceRootPath(name string) WorkspaceRootPath {
+	return WorkspaceRootPath{
 		rootPath: path.Clean(name),
 	}
 }
 
 // Join returns the specified path name joined to the root.
 // It returns an error if the resulting path is not a strict child of the root path.
-func (p *RootPath) Join(name string) (string, error) {
+func (p *WorkspaceRootPath) Join(name string) (string, error) {
 	absPath := path.Join(p.rootPath, name)
 
 	// Don't allow escaping the specified root using relative paths.

libs/filer/workspace_root_path_test.go

@@ -9,7 +9,7 @@ import (
 
 func testRootPath(t *testing.T, uncleanRoot string) {
 	cleanRoot := path.Clean(uncleanRoot)
-	rp := NewRootPath(uncleanRoot)
+	rp := NewWorkspaceRootPath(uncleanRoot)
 
 	remotePath, err := rp.Join("a/b/c")
 	assert.NoError(t, err)