Fix some errors detected by mypy

generator/utils.py

@@ -303,11 +303,11 @@ def _get_additional_methods(self, class_name: str) -> List[str]:
         indent = " " * 4
         if class_name == "Position":
             return [
-                "def __eq__(self, o: 'Position') -> Union[bool, 'NotImplemented']:",
+                "def __eq__(self, o: object) -> bool:",
                 f"{indent}if not isinstance(o, Position):",
                 f"{indent}{indent}return NotImplemented",
                 f"{indent}return (self.line, self.character) == (o.line, o.character)",
-                "def __gt__(self, o: 'Position') -> Union[bool, 'NotImplemented']:",
+                "def __gt__(self, o: 'Position') -> bool:",
                 f"{indent}if not isinstance(o, Position):",
                 f"{indent}{indent}return NotImplemented",
                 f"{indent}return (self.line, self.character) > (o.line, o.character)",
@@ -316,7 +316,7 @@ def _get_additional_methods(self, class_name: str) -> List[str]:
             ]
         if class_name == "Range":
             return [
-                "def __eq__(self, o: 'Range') -> Union[bool, 'NotImplemented']:",
+                "def __eq__(self, o: object) -> bool:",
                 f"{indent}if not isinstance(o, Range):",
                 f"{indent}{indent}return NotImplemented",
                 f"{indent}return (self.start == o.start) and (self.end == o.end)",
@@ -325,7 +325,7 @@ def _get_additional_methods(self, class_name: str) -> List[str]:
             ]
         if class_name == "Location":
             return [
-                "def __eq__(self, o:'Location') -> Union[bool, 'NotImplemented']:",
+                "def __eq__(self, o: object) -> bool:",
                 f"{indent}if not isinstance(o, Location):",
                 f"{indent}{indent}return NotImplemented",
                 f"{indent}return (self.uri == o.uri) and (self.range == o.range)",
@@ -925,7 +925,7 @@ def _get_utility_code(self, lsp_model: model.LSPModel) -> List[str]:
             f"_KEYWORD_CLASSES = [{', '.join(sorted(set(self._keyword_classes)))}]"
         ]
         code_lines += [
-            "def is_keyword_class(cls) -> bool:",
+            "def is_keyword_class(cls: type) -> bool:",
             '    """Returns true if the class has a property that may be python keyword."""',
             "    return any(cls is c for c in _KEYWORD_CLASSES)",
             "",
@@ -938,7 +938,7 @@ def _get_utility_code(self, lsp_model: model.LSPModel) -> List[str]:
             f"_SPECIAL_CLASSES = [{', '.join(sorted(set(self._special_classes)))}]"
         ]
         code_lines += [
-            "def is_special_class(cls) -> bool:",
+            "def is_special_class(cls: type) -> bool:",
             '    """Returns true if the class or its properties require special handling."""',
             "    return any(cls is c for c in _SPECIAL_CLASSES)",
             "",
@@ -961,7 +961,7 @@ def _get_utility_code(self, lsp_model: model.LSPModel) -> List[str]:
             f"_SPECIAL_PROPERTIES = [{', '.join(sorted(set(self._special_properties)))}]"
         ]
         code_lines += [
-            "def is_special_property(cls, property_name:str) -> bool:",
+            "def is_special_property(cls: type, property_name:str) -> bool:",
             '    """Returns true if the class or its properties require special handling.',
             "    Example:",
             "      Consider RenameRegistrationOptions",
@@ -978,7 +978,7 @@ def _get_utility_code(self, lsp_model: model.LSPModel) -> List[str]:
             "",
         ]
 
-        code_lines += ["", "ALL_TYPES_MAP = {"]
+        code_lines += ["", "ALL_TYPES_MAP: Dict[str, type] = {"]
         code_lines += sorted([f"'{name}': {name}," for name in set(self._types.keys())])
         code_lines += ["}", ""]
 
@@ -1061,9 +1061,8 @@ def _generate_hook(
 
         hook_name = f"_{_to_snake_case(property_def.name)}_hook"
         indent = " " * 4
-        code_lines = [
-            f"def {hook_name}(object_: Any, _: type):",
-        ]
+        code_lines = []
+        return_types = []
 
         has_base_type = False
         ref_types = []
@@ -1078,17 +1077,21 @@ def _generate_hook(
             return []
 
         if property_def.optional:
+            return_types.append("None")
             code_lines += [
                 f"{indent}if object_ is None:",
                 f"{indent*2}return None",
             ]
 
         if has_base_type:
+            return_types += ["bool", "int", "str", "float"]
             code_lines += [
                 f"{indent}if isinstance(object_, (bool, int, str, float)):",
                 f"{indent*2}return object_",
             ]
 
+        return_types += ref_types
+
         if len(ref_types) == 1:
             code_lines += [
                 f"{indent}return converter.structure(object_, {ref_types[0]})",
@@ -1106,6 +1109,9 @@ def _generate_hook(
                 f"{indent*2}return converter.structure(object_, {opt})",
             ]
 
+        declaration = f"def {hook_name}(object_: Any, _: type) -> Union[{', '.join(return_types)}]:"
+        code_lines.insert(0, declaration)
+
         type_name = self._generate_type_name(property_def.type, None, "lsp_types.")
         if property_def.optional:
             type_name = f"Optional[{type_name}]"

lsprotocol/converters.py

@@ -27,7 +27,7 @@ def resolve_forward_references() -> None:
 
 
 def get_converter(
-    converter: Optional[cattrs.Converter] = cattrs.Converter(),
+    converter: cattrs.Converter = cattrs.Converter(),
 ) -> cattrs.Converter:
     """Adds cattrs hooks for LSP lsp_types to the given converter."""
     resolve_forward_references()
@@ -39,10 +39,8 @@ def get_converter(
 def _register_required_structure_hooks(
     converter: cattrs.Converter,
 ) -> cattrs.Converter:
-    def _lsp_object_hook(
-        object_: Any, type_: type
-    ) -> Union[lsp_types.LSPObject, lsp_types.LSPArray, str, int, float, bool, None]:
-        if not object_:
+    def _lsp_object_hook(object_: Any, type_: type) -> Any:
+        if object_ is None:
             return object_
         else:
             for type_ in [str, bool, int, float, list]:
@@ -165,7 +163,7 @@ def _notebook_filter_hook(
 
 
 def _register_custom_property_hooks(converter: cattrs.Converter) -> cattrs.Converter:
-    def _to_camel_case(name: str):
+    def _to_camel_case(name: str) -> str:
         # TODO: when min Python becomes >= 3.9, then update this to:
         # `return name.removesuffix("_")`.
         new_name = name[:-1] if name.endswith("_") else name

lsprotocol/validators.py

@@ -2,13 +2,20 @@
 # Licensed under the MIT License.
 
 
-from typing import Any
+from typing import TYPE_CHECKING, Any
+
+if TYPE_CHECKING:
+    import attrs
 
 INTEGER_MIN_VALUE = -(2**31)
 INTEGER_MAX_VALUE = 2**31 - 1
 
 
-def integer_validator(instance: Any, attribute: Any, value: Any) -> bool:
+def integer_validator(
+    instance: Any,
+    attribute: "attrs.Attribute[int]",
+    value: Any,
+) -> bool:
     """Validates that integer value belongs in the range expected by LSP."""
     if not isinstance(value, int) or not (
         INTEGER_MIN_VALUE <= value <= INTEGER_MAX_VALUE
@@ -24,7 +31,11 @@ def integer_validator(instance: Any, attribute: Any, value: Any) -> bool:
 UINTEGER_MAX_VALUE = 2**31 - 1
 
 
-def uinteger_validator(instance: Any, attribute: Any, value: Any) -> bool:
+def uinteger_validator(
+    instance: Any,
+    attribute: "attrs.Attribute[int]",
+    value: Any,
+) -> bool:
     """Validates that unsigned integer value belongs in the range expected by
     LSP."""
     if not isinstance(value, int) or not (

pyproject.toml

@@ -49,4 +49,13 @@ exclude = [
   "SUPPORT.md",
 ]
 
-
+[tool.mypy]
+files = "lsprotocol"
+show_error_codes = true
+strict = true
+enable_error_code = [
+    "ignore-without-code",
+    "redundant-expr",
+    "truthy-bool",
+]
+enable_recursive_aliases = true