Enable mypy for typemap (#3)

`tests` is still busted (maybe fundamentally until we have typechecking?)

Author: msullivan

tests/test_cqa.py

@@ -29,7 +29,7 @@ def test_cqa_ruff_check(project_root):
 
 def test_cqa_ruff_format_check(project_root):
     """Test that code is properly formatted according to ruff."""
-    # Ruff format respects pyproject.toml exclusions (_vendor is excluded)
+    # Ruff format respects pyproject.toml exclusions
     result = subprocess.run(
         [sys.executable, "-m", "ruff", "format", "--check", "."],
         capture_output=True,
@@ -43,12 +43,11 @@ def test_cqa_ruff_format_check(project_root):
         )
 
 
-@pytest.mark.skip(reason="Mypy is not working yet")
 def test_cqa_mypy(project_root):
     """Test that code passes mypy type checking."""
     # Mypy uses configuration from pyproject.toml
-    # Run on the whole project (pi package and tests), excluding _vendor
-    for subdir in ["pi", "tests/fixtures"]:
+    # Run on typemap -- tests not ready yet
+    for subdir in ["typemap"]:
         result = subprocess.run(
             [
                 sys.executable,

typemap/__init__.py

@@ -77,7 +77,7 @@ def _box(cls: type[Any], args: dict[str, Any]) -> Boxed:
 
         return Boxed(cls, boxed_bases, args)
 
-    if isinstance(cls, (typing._GenericAlias, types.GenericAlias)):
+    if isinstance(cls, (typing._GenericAlias, types.GenericAlias)):  # type: ignore[attr-defined]
         # XXX this feels out of place, `box()` needs to only accept types.
         args = dict(
             zip(cls.__origin__.__parameters__, cls.__args__, strict=True)
@@ -184,7 +184,7 @@ def apply(cls: type[Any]) -> dict[str, Any]:
             annos.update(af)
 
         for name, stuff in boxed.cls.__dict__.items():
-            if name in typing.EXCLUDED_ATTRIBUTES:
+            if name in typing.EXCLUDED_ATTRIBUTES:  # type: ignore[attr-defined]
                 continue
 
             stuff = inspect.unwrap(stuff)

typemap/type_eval/_apply_generic.py

@@ -16,11 +16,11 @@ def eval_call(func: types.FunctionType, /, *args: Any, **kwargs: Any) -> Any:
 
 
 def _eval_call(func: types.FunctionType, /, *args: Any, **kwargs: Any) -> Any:
-    vars = {}
+    vars: dict[str, Any] = {}
 
     params = func.__type_params__
     for p in params:
-        if p.__bound__ is next.CallSpec:
+        if hasattr(p, "__bound__") and p.__bound__ is next.CallSpec:
             vars[p.__name__] = next._CallSpecWrapper(args, kwargs, func)
         else:
             vars[p.__name__] = p
@@ -29,6 +29,8 @@ def _eval_call(func: types.FunctionType, /, *args: Any, **kwargs: Any) -> Any:
         af = func.__annotate__
     except AttributeError:
         raise ValueError("func has no __annotate__ attribute")
+    if not af:
+        raise ValueError("func has no __annotate__ attribute")
 
     af_args = tuple(
         types.CellType(vars[name]) for name in af.__code__.co_freevars

typemap/type_eval/_eval_call.py

@@ -99,7 +99,7 @@ def _eval_type_type(obj: type, ctx: EvalContext):
     if isinstance(obj, type) and issubclass(obj, typing.Generic):
         ret = type(
             obj.__name__,
-            (typing.Protocol,),
+            (typing.cast(type, typing.Protocol),),
             {
                 "__module__": obj.__module__,
                 "__name__": obj.__name__,
@@ -129,6 +129,7 @@ def _eval_type_var(obj: typing.TypeVar, ctx: EvalContext):
 
 @_eval_types_impl.register
 def _eval_type_alias(obj: typing.TypeAliasType, ctx: EvalContext):
+    assert obj.__module__  # FIXME: or can this really happen?
     func = obj.evaluate_value
     mod = sys.modules[obj.__module__]
     ff = types.FunctionType(func.__code__, mod.__dict__, None, None, ())
@@ -142,7 +143,7 @@ def _eval_generic(obj: types.GenericAlias, ctx: EvalContext):
         # This is a GenericAlias over a Python class, e.g. `dict[str, int]`
         # Let's reconstruct it by evaluating all arguments
         new_args = tuple(_eval_types(arg, ctx) for arg in obj.__args__)
-        return obj.__origin__[new_args]
+        return obj.__origin__[new_args]  # type: ignore[index]
 
     func = obj.evaluate_value
 
@@ -169,5 +170,6 @@ def _eval_generic(obj: types.GenericAlias, ctx: EvalContext):
 
 @_eval_types_impl.register
 def _eval_union(obj: typing.Union, ctx: EvalContext):  # type: ignore
-    new_args = tuple(_eval_types(arg, ctx) for arg in obj.__args__)
+    args: typing.Sequence[typing.Any] = obj.__args__
+    new_args = tuple(_eval_types(arg, ctx) for arg in args)
     return typing.Union[new_args]

typemap/type_eval/_eval_typing.py

@@ -16,7 +16,8 @@ class CallSpec:
 class _CallSpecWrapper:
     _args: tuple[typing.Any]
     _kwargs: dict[str, typing.Any]
-    _func: types.FunctionType | types.MethodType
+    # TODO: Support MethodType!
+    _func: types.FunctionType  # | types.MethodType
 
     @property
     def args(self) -> None:
@@ -32,7 +33,7 @@ class _CallKwarg:
     name: str
 
 
-@typing._SpecialForm
+@typing._SpecialForm  # type: ignore[call-arg]
 def CallSpecKwargs(self, spec: _CallSpecWrapper) -> list[_CallKwarg]:
     ff = types.FunctionType(
         spec._func.__code__,
@@ -85,7 +86,7 @@ class DirProperties(metaclass=DirPropertiesMeta):
 
 class NewProtocolMeta(type):
     def __getitem__(cls, val: list[Property]):
-        dct = {}
+        dct: dict[str, object] = {}
         dct["__annotations__"] = {prop.name: prop.type for prop in val}
 
         module_name = __name__
@@ -99,7 +100,7 @@ def __getitem__(cls, val: list[Property]):
 
         dct["__module__"] = module_name
 
-        mcls = type(typing.Protocol)
+        mcls: type = type(typing.cast(type, typing.Protocol))
         cls = mcls(name, (typing.Protocol,), dct)
         return cls