Add PositionEncodingKind hook (#272)

Fixes #270

packages/python/lsprotocol/_hooks.py

@@ -146,6 +146,11 @@ def _references_provider_hook(
             return object_
         return converter.structure(object_, lsp_types.ReferenceOptions)
 
+    def _position_encoding_hook(
+        object_: Union[lsp_types.PositionEncodingKind, OptionalPrimitive], _: type
+    ) -> Union[lsp_types.PositionEncodingKind, OptionalPrimitive]:
+        return object_
+
     def _document_highlight_provider_hook(
         object_: Any, _: type
     ) -> Union[OptionalPrimitive, lsp_types.DocumentHighlightOptions]:
@@ -926,6 +931,15 @@ def _notebook_sync_option_selector_hook(
             ],
             _notebook_sync_option_selector_hook,
         ),
+        (
+            Optional[
+                Union[
+                    lsp_types.PositionEncodingKind,
+                    str,
+                ]
+            ],
+            _position_encoding_hook,
+        ),
     ]
     for type_, hook in structure_hooks:
         converter.register_structure_hook(type_, hook)

tests/python/test_cattrs_special_cases.py

@@ -1,6 +1,9 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
+from typing import Optional, Union
+
+import attrs
 import hamcrest
 import pytest
 from cattrs.errors import ClassValidationError
@@ -274,3 +277,30 @@ def test_notebook_sync_options():
         converter.unstructure(obj, lsp.NotebookDocumentSyncOptions),
         hamcrest.is_(data),
     )
+
+
+@attrs.define
+class TestPosEncoding:
+    """Defines the capabilities provided by a language
+    server."""
+
+    position_encoding: Optional[Union[lsp.PositionEncodingKind, str]] = attrs.field(
+        default=None
+    )
+
+
+@pytest.mark.parametrize("e", [None, "utf-8", "utf-16", "utf-32", "something"])
+def test_position_encoding_kind(e):
+    data = {"positionEncoding": e}
+    converter = cv.get_converter()
+    obj = converter.structure(data, TestPosEncoding)
+    hamcrest.assert_that(obj, hamcrest.instance_of(TestPosEncoding))
+
+    if e is None:
+        hamcrest.assert_that(
+            converter.unstructure(obj, TestPosEncoding), hamcrest.is_({})
+        )
+    else:
+        hamcrest.assert_that(
+            converter.unstructure(obj, TestPosEncoding), hamcrest.is_(data)
+        )