establish new errors.IllegalDestination

Author: tfeldmann

fs/base.py

@@ -21,11 +21,11 @@
 from contextlib import closing
 from functools import partial, wraps
 
-from . import copy, errors, fsencode, iotools, tools, walk, wildcard, glob
+from . import copy, errors, fsencode, glob, iotools, tools, walk, wildcard
 from .copy import copy_modified_time
 from .glob import BoundGlobber
 from .mode import validate_open_mode
-from .path import abspath, join, normpath
+from .path import abspath, isbase, join, normpath
 from .time import datetime_to_epoch
 from .walk import Walker
 
@@ -425,11 +425,10 @@ def copy(
         with self._lock:
             _src_path = self.validatepath(src_path)
             _dst_path = self.validatepath(dst_path)
+            if _src_path == _dst_path:
+                raise errors.IllegalDestination(dst_path)
             if not overwrite and self.exists(_dst_path):
                 raise errors.DestinationExists(dst_path)
-            if overwrite and _src_path == _dst_path:
-                # exit early when copying a file onto itself
-                return
             with closing(self.open(_src_path, "rb")) as read_file:
                 # FIXME(@althonos): typing complains because open return IO
                 self.upload(_dst_path, read_file)  # type: ignore
@@ -1093,6 +1092,12 @@ def movedir(self, src_path, dst_path, create=False, preserve_time=False):
         from .move import move_dir
 
         with self._lock:
+            _src_path = self.validatepath(src_path)
+            _dst_path = self.validatepath(dst_path)
+            if _src_path == _dst_path:
+                return
+            if isbase(_src_path, _dst_path):
+                raise errors.IllegalDestination(dst_path)
             if not create and not self.exists(dst_path):
                 raise errors.ResourceNotFound(dst_path)
             move_dir(self, src_path, self, dst_path, preserve_time=preserve_time)

fs/errors.py

@@ -32,9 +32,9 @@
     "FilesystemClosed",
     "FSError",
     "IllegalBackReference",
+    "IllegalDestination",
     "InsufficientStorage",
     "InvalidCharsInPath",
-    "InvalidMoveOperation",
     "InvalidPath",
     "MissingInfoNamespace",
     "NoSysPath",
@@ -241,16 +241,14 @@ class RemoveRootError(OperationFailed):
     default_message = "root directory may not be removed"
 
 
-class IllegalMoveDestination(OperationFailed):
-    """Attempt to move a folder into its own subfolder."""
+class IllegalDestination(OperationFailed):
+    """The given destination cannot be used for the operation.
 
-    default_message = "'{path}' cannot be moved into itself"
-
-
-class IllegalCopyDestination(OperationFailed):
-    """Attempt to copy a folder into its own subfolder."""
+    This error will occur when attempting to move / copy a folder into itself or copying
+    a file onto itself.
+    """
 
-    default_message = "'{path}' cannot be copied into itself"
+    default_message = "'{path}' is not a legal destination"
 
 
 class ResourceError(FSError):

fs/memoryfs.py

@@ -19,7 +19,7 @@
 from .enums import ResourceType, Seek
 from .info import Info
 from .mode import Mode
-from .path import iteratepath, normpath, split
+from .path import isbase, iteratepath, normpath, split
 
 if typing.TYPE_CHECKING:
     from typing import (
@@ -478,8 +478,17 @@ def move(self, src_path, dst_path, overwrite=False, preserve_time=False):
                 copy_modified_time(self, src_path, self, dst_path)
 
     def movedir(self, src_path, dst_path, create=False, preserve_time=False):
-        src_dir, src_name = split(self.validatepath(src_path))
-        dst_dir, dst_name = split(self.validatepath(dst_path))
+        _src_path = self.validatepath(src_path)
+        _dst_path = self.validatepath(dst_path)
+        dst_dir, dst_name = split(_dst_path)
+        src_dir, src_name = split(_src_path)
+
+        # move a dir onto itself
+        if _src_path == _dst_path:
+            return
+        # move a dir into itself
+        if isbase(_src_path, _dst_path):
+            raise errors.IllegalDestination(dst_path)
 
         with self._lock:
             src_dir_entry = self._get_dir_entry(src_dir)

fs/test.py

@@ -1830,20 +1830,20 @@ def test_move_file_onto_itself_relpath(self):
 
     def test_copy_file_onto_itself(self):
         self.fs.writetext("file.txt", "Hello")
-        self.fs.copy("file.txt", "file.txt", overwrite=True)
-        self.assert_text("file.txt", "Hello")
-
-        with self.assertRaises(errors.DestinationExists):
+        with self.assertRaises(errors.IllegalDestination):
+            self.fs.copy("file.txt", "file.txt", overwrite=True)
+        with self.assertRaises(errors.IllegalDestination):
             self.fs.copy("file.txt", "file.txt", overwrite=False)
+        self.assert_text("file.txt", "Hello")
 
     def test_copy_file_onto_itself_relpath(self):
         subdir = self.fs.makedir("sub")
         subdir.writetext("file.txt", "Hello")
-        self.fs.copy("sub/file.txt", "sub/../sub/file.txt", overwrite=True)
-        self.assert_text("sub/file.txt", "Hello")
-
-        with self.assertRaises(errors.DestinationExists):
+        with self.assertRaises(errors.IllegalDestination):
+            self.fs.copy("sub/file.txt", "sub/../sub/file.txt", overwrite=True)
+        with self.assertRaises(errors.IllegalDestination):
             self.fs.copy("sub/file.txt", "sub/../sub/file.txt", overwrite=False)
+        self.assert_text("sub/file.txt", "Hello")
 
     def test_copydir(self):
         self.fs.makedirs("foo/bar/baz/egg")
@@ -1868,21 +1868,18 @@ def test_copydir_onto_itself(self):
         sub = folder.makedir("sub")
         sub.writetext("file2.txt", "Hello2")
 
-        self.fs.copydir("folder", "folder")
+        with self.assertRaises(errors.IllegalDestination):
+            self.fs.copydir("folder", "folder")
         self.assert_text("folder/file1.txt", "Hello1")
         self.assert_text("folder/sub/file2.txt", "Hello2")
 
     def test_copydir_into_its_own_subfolder(self):
-        # TODO: This test hangs forever at the moment.
-        #
         # folder = self.fs.makedir("folder")
         # folder.writetext("file1.txt", "Hello1")
         # sub = folder.makedir("sub")
         # sub.writetext("file2.txt", "Hello2")
-        # self.fs.copydir("folder", "folder/sub/")
-        # self.assert_text("folder/file1.txt", "Hello1")
-        # self.assert_text("folder/sub/file1.txt", "Hello1")
-        # self.assert_not_exists("folder/sub/file2.txt")
+        # with self.assertRaises(errors.IllegalDestination):
+        #     self.fs.copydir("folder", "folder/sub/")
         pass
 
     def test_movedir(self):
@@ -1924,7 +1921,7 @@ def test_movedir_into_its_own_subfolder(self):
         sub = folder.makedir("sub")
         sub.writetext("file2.txt", "Hello2")
 
-        with self.assertRaises(errors.IllegalMoveDestination):
+        with self.assertRaises(errors.IllegalDestination):
             self.fs.movedir("folder", "folder/sub/")
 
     def test_match(self):