Merge pull request #246 from 56kyle/feature/restrict-handler-registration-with-generics

Prevent registering type handlers using types that have specified generics (Dict is okay, Dict[str, int] is not)

Author: 56kyle

src/pytest_static/type_handler.py

@@ -7,6 +7,7 @@
 from typing import TYPE_CHECKING
 from typing import Any
 from typing import Callable
+from typing import get_args
 
 from pytest_static.util import get_base_type
 
@@ -23,6 +24,12 @@ def __init__(self) -> None:
         self._mapping: dict[Any, list[TypeHandler]] = {}
         self._proxy: types.MappingProxyType[Any, list[TypeHandler]] = types.MappingProxyType(self._mapping)
 
+    @classmethod
+    def _validate_has_no_generic(cls, typ: Any) -> None:
+        """Validates that the provided typ has no generic type."""
+        if get_args(typ):
+            raise TypeError(f"Cannot register a type handler type containing generics: {typ}")
+
     def __getitem__(self, key: Any) -> Any:
         """Returns from proxy."""
         return self._proxy.__getitem__(key)
@@ -47,6 +54,8 @@ def my_function_name(base_type, type_args):
             type_handlers.get_instances(int) => (100, 1000, 1, 2, 3, 4, 5)
             type_handlers.get_instances(float) => (1.0, 2.0, 3.0, 4.0, 5.0)
         """
+        for arg in args:
+            self._validate_has_no_generic(arg)
 
         def decorator(fn: TypeHandler) -> TypeHandler:
             for key in args:

tests/unit_tests/test_type_handler.py

@@ -1,5 +1,9 @@
+from typing import Any
+from typing import List
+
 import pytest
 
+from pytest_static.custom_typing import T
 from pytest_static.custom_typing import TypeHandler
 from pytest_static.type_handler import TypeHandlerRegistry
 
@@ -37,6 +41,13 @@ def test_register_with_existing(
         assert type_handler_registry__basic.get(int, None) is not None
         assert tuple(type_handler_registry__basic.get(int, None)[0](int, ())) == (1, 2, 3)
 
+    @pytest.mark.parametrize("generic", [str, list[str], T])
+    def test_register_with_generic(
+        self, type_handler_registry__basic: TypeHandlerRegistry, basic_handler: TypeHandler, generic: Any
+    ) -> None:
+        with pytest.raises(TypeError):
+            type_handler_registry__basic.register(List[generic])(basic_handler)
+
     def test_clear_with_unregistered(self, type_handler_registry: TypeHandlerRegistry) -> None:
         assert type_handler_registry.get(int, None) is None
         type_handler_registry.clear(int)