fix: Fix copying symlink files for Windows (#7351)

* fix: Fix copying symlink files for Windows

* make black happy

samcli/lib/utils/osutils.py

@@ -2,6 +2,7 @@
 Common OS utilities
 """
 
+import errno
 import io
 import logging
 import os
@@ -178,7 +179,15 @@ def copytree(source, destination, ignore=None):
         if os.path.isdir(new_source):
             copytree(new_source, new_destination, ignore=ignore)
         else:
-            shutil.copy2(new_source, new_destination)
+            try:
+                shutil.copy2(new_source, new_destination)
+            except OSError as e:
+                if e.errno != errno.EINVAL:
+                    raise e
+
+                # Symlinks do not get copied for Windows using shutil.copy2, which is why
+                # they are handled separately here.
+                create_symlink_or_copy(new_source, new_destination)
 
 
 def convert_files_to_unix_line_endings(path: str, target_files: Optional[List[str]] = None) -> None:

tests/unit/lib/utils/test_osutils.py

@@ -90,6 +90,69 @@ def test_must_delete_if_path_exist(self, patched_rmtree, patched_path):
         patched_rmtree.assert_called_with(mock_path_obj)
 
 
+class Test_copytree(TestCase):
+    @patch("samcli.lib.utils.osutils.Path")
+    @patch("samcli.lib.utils.osutils.os")
+    @patch("samcli.lib.utils.osutils.shutil.copy2")
+    def test_must_copytree(self, patched_copy2, patched_os, patched_path):
+        source_path = "mock-source/path"
+        destination_path = "mock-destination/path"
+        mock_path_obj = Mock()
+        patched_path.exists.return_value = True
+        patched_os.path.return_value = mock_path_obj
+
+        patched_os.path.join.side_effect = [source_path, destination_path]
+        patched_os.path.isdir.return_value = False
+        patched_os.listdir.return_value = ["mock-source-file1"]
+        osutils.copytree(source_path, destination_path)
+
+        patched_os.path.join.assert_called()
+        patched_copy2.assert_called_with(source_path, destination_path)
+
+    @patch("samcli.lib.utils.osutils.Path")
+    @patch("samcli.lib.utils.osutils.os")
+    @patch("samcli.lib.utils.osutils.shutil.copy2")
+    def test_copytree_throws_oserror_path_exists(self, patched_copy2, patched_os, patched_path):
+        source_path = "mock-source/path"
+        destination_path = "mock-destination/path"
+        mock_path_obj = Mock()
+        patched_path.exists.return_value = True
+        patched_os.path.return_value = mock_path_obj
+        patched_copy2.side_effect = OSError("mock-os-error")
+
+        patched_os.path.join.side_effect = [source_path, destination_path]
+        patched_os.path.isdir.return_value = False
+        patched_os.listdir.return_value = ["mock-source-file1"]
+        with self.assertRaises(OSError):
+            osutils.copytree(source_path, destination_path)
+
+        patched_os.path.join.assert_called()
+        patched_copy2.assert_called_with(source_path, destination_path)
+
+    @patch("samcli.lib.utils.osutils.create_symlink_or_copy")
+    @patch("samcli.lib.utils.osutils.Path")
+    @patch("samcli.lib.utils.osutils.os")
+    @patch("samcli.lib.utils.osutils.shutil.copy2")
+    def test_copytree_symlink_copy_error_handling(
+        self, patched_copy2, patched_os, patched_path, patched_create_symlink_or_copy
+    ):
+        source_path = "mock-source/path"
+        destination_path = "mock-destination/path"
+        mock_path_obj = Mock()
+        patched_path.exists.return_value = True
+        patched_os.path.return_value = mock_path_obj
+        patched_copy2.side_effect = OSError(22, "mock-os-error")
+
+        patched_os.path.join.side_effect = [source_path, destination_path]
+        patched_os.path.isdir.return_value = False
+        patched_os.listdir.return_value = ["mock-source-file1"]
+        osutils.copytree(source_path, destination_path)
+
+        patched_os.path.join.assert_called()
+        patched_copy2.assert_called_with(source_path, destination_path)
+        patched_create_symlink_or_copy.assert_called_with(source_path, destination_path)
+
+
 class Test_create_symlink_or_copy(TestCase):
     @patch("samcli.lib.utils.osutils.Path")
     @patch("samcli.lib.utils.osutils.os")