fix: Recursively call method on directory children (#6402)

* Recursively call method on directory children

* Add test and typing

* Catch Windows error when trying to determine resolved file path

* Test positive case and add file in console output

samcli/lib/utils/tar.py

@@ -62,7 +62,7 @@ def create_tarball(
         tarballfile.close()
 
 
-def _validate_destinations_exists(tar_paths: List[Union[str, Path]]) -> bool:
+def _validate_destinations_exists(tar_paths: Union[List[Union[str, Path]], List[Path]]) -> bool:
     """
     Validates whether the destination of a symlink exists by resolving the link
     and checking the resolved path.
@@ -79,9 +79,22 @@ def _validate_destinations_exists(tar_paths: List[Union[str, Path]]) -> bool:
     """
     for file in tar_paths:
         file_path_obj = Path(file)
-        resolved_path = file_path_obj.resolve()
 
-        if file_path_obj.is_symlink() and not resolved_path.exists():
+        try:
+            resolved_path = file_path_obj.resolve()
+        except OSError:
+            # this exception will occur on Windows and will return
+            # a WinError 123
+            LOG.warning(f"Failed to resolve file {file_path_obj} on the host machine")
+            return False
+
+        if file_path_obj.is_dir():
+            # recursively call this method to validate the children are not symlinks to empty locations
+            children = list(file_path_obj.iterdir())
+            if not _validate_destinations_exists(children):
+                # exits early
+                return False
+        elif file_path_obj.is_symlink() and not resolved_path.exists():
             LOG.warning(f"Symlinked file {file_path_obj} -> {resolved_path} does not exist!")
             return False
 

tests/unit/lib/utils/test_tar.py

@@ -196,9 +196,38 @@ def test_validating_symlinked_tar_path(self, does_resolved_exist, path_mock):
         mock_path_object.resolve.return_value = mock_resolved_object
         mock_path_object.is_symlink = Mock()
         mock_path_object.is_symlink.return_value = True
+        mock_path_object.is_dir.return_value = False
 
         path_mock.return_value = mock_path_object
 
         result = _validate_destinations_exists(["mock_path"])
 
         self.assertEqual(result, does_resolved_exist)
+
+    @parameterized.expand(
+        [
+            (True,),
+            (False,),
+        ]
+    )
+    @patch("samcli.lib.utils.tar.Path")
+    def test_validating_symlinked_tar_path_directory(self, file_exists, path_mock):
+        mock_child_resolve = Mock()
+        mock_child_resolve.exists.return_value = file_exists
+
+        mock_child = Mock()
+        mock_child.is_symlink.return_value = True
+        mock_child.is_dir.return_value = False
+        mock_child.resolve.return_value = mock_child_resolve
+
+        mock_dir_object = Mock()
+        mock_dir_object.is_symlink.return_value = False
+        mock_dir_object.is_dir.return_value = True
+        mock_dir_object.iterdir.return_value = ["mock_child"]
+        mock_dir_object.resolve = Mock()
+
+        path_mock.side_effect = [mock_dir_object, mock_child]
+
+        result = _validate_destinations_exists(["mock_folder"])
+
+        self.assertEqual(result, file_exists)