Merge remote-tracking branch 'upstream/master' into method-subtype-checkmember

Author: ilevkivskyi

mypy/checkexpr.py

@@ -2357,7 +2357,8 @@ def check_argument_count(
 
         # Check for too many or few values for formals.
         for i, kind in enumerate(callee.arg_kinds):
-            if kind.is_required() and not formal_to_actual[i] and not is_unexpected_arg_error:
+            mapped_args = formal_to_actual[i]
+            if kind.is_required() and not mapped_args and not is_unexpected_arg_error:
                 # No actual for a mandatory formal
                 if kind.is_positional():
                     self.msg.too_few_arguments(callee, context, actual_names)
@@ -2368,28 +2369,36 @@ def check_argument_count(
                     self.msg.missing_named_argument(callee, context, argname)
                 ok = False
             elif not kind.is_star() and is_duplicate_mapping(
-                formal_to_actual[i], actual_types, actual_kinds
+                mapped_args, actual_types, actual_kinds
             ):
                 if self.chk.in_checked_function() or isinstance(
-                    get_proper_type(actual_types[formal_to_actual[i][0]]), TupleType
+                    get_proper_type(actual_types[mapped_args[0]]), TupleType
                 ):
                     self.msg.duplicate_argument_value(callee, i, context)
                     ok = False
             elif (
                 kind.is_named()
-                and formal_to_actual[i]
-                and actual_kinds[formal_to_actual[i][0]] not in [nodes.ARG_NAMED, nodes.ARG_STAR2]
+                and mapped_args
+                and actual_kinds[mapped_args[0]] not in [nodes.ARG_NAMED, nodes.ARG_STAR2]
             ):
                 # Positional argument when expecting a keyword argument.
                 self.msg.too_many_positional_arguments(callee, context)
                 ok = False
-            elif (
-                callee.param_spec() is not None
-                and not formal_to_actual[i]
-                and callee.special_sig != "partial"
-            ):
-                self.msg.too_few_arguments(callee, context, actual_names)
-                ok = False
+            elif callee.param_spec() is not None:
+                if not mapped_args and callee.special_sig != "partial":
+                    self.msg.too_few_arguments(callee, context, actual_names)
+                    ok = False
+                elif len(mapped_args) > 1:
+                    paramspec_entries = sum(
+                        isinstance(get_proper_type(actual_types[k]), ParamSpecType)
+                        for k in mapped_args
+                    )
+                    if actual_kinds[mapped_args[0]] == nodes.ARG_STAR and paramspec_entries > 1:
+                        self.msg.fail("ParamSpec.args should only be passed once", context)
+                        ok = False
+                    if actual_kinds[mapped_args[0]] == nodes.ARG_STAR2 and paramspec_entries > 1:
+                        self.msg.fail("ParamSpec.kwargs should only be passed once", context)
+                        ok = False
         return ok
 
     def check_for_extra_actual_arguments(

mypy/checkmember.py

@@ -42,6 +42,7 @@
     erase_to_bound,
     freeze_all_type_vars,
     function_type,
+    get_all_type_vars,
     get_type_vars,
     make_simplified_union,
     supported_self_type,
@@ -606,7 +607,10 @@ def analyze_member_var_access(
             setattr_meth = info.get_method("__setattr__")
             if setattr_meth and setattr_meth.info.fullname != "builtins.object":
                 bound_type = analyze_decorator_or_funcbase_access(
-                    defn=setattr_meth, itype=itype, name=name, mx=mx.copy_modified(is_lvalue=False)
+                    defn=setattr_meth,
+                    itype=itype,
+                    name="__setattr__",
+                    mx=mx.copy_modified(is_lvalue=False),
                 )
                 typ = map_instance_to_supertype(itype, setattr_meth.info)
                 setattr_type = get_proper_type(expand_type_by_instance(bound_type, typ))
@@ -872,15 +876,13 @@ def analyze_var(
                 mx.msg.read_only_property(name, itype.type, mx.context)
             if var.is_classvar:
                 mx.msg.cant_assign_to_classvar(name, mx.context)
-        t = freshen_all_functions_type_vars(typ)
-        t = expand_self_type_if_needed(t, mx, var, original_itype)
-        t = expand_type_by_instance(t, itype)
-        freeze_all_type_vars(t)
-        result = t
-        typ = get_proper_type(typ)
+        # This is the most common case for variables, so start with this.
+        result = expand_without_binding(typ, var, itype, original_itype, mx)
 
+        # A non-None value indicates that we should actually bind self for this variable.
         call_type: ProperType | None = None
         if var.is_initialized_in_class and (not is_instance_var(var) or mx.is_operator):
+            typ = get_proper_type(typ)
             if isinstance(typ, FunctionLike) and not typ.is_type_obj():
                 call_type = typ
             elif var.is_property:
@@ -890,37 +892,23 @@ def analyze_var(
             else:
                 call_type = typ
 
+        # Bound variables with callable types are treated like methods
+        # (these are usually method aliases like __rmul__ = __mul__).
         if isinstance(call_type, FunctionLike) and not call_type.is_type_obj():
-            if mx.is_lvalue and not mx.suppress_errors:
-                if var.is_property and not var.is_settable_property:
-                    mx.msg.read_only_property(name, itype.type, mx.context)
-                elif not var.is_property:
-                    mx.msg.cant_assign_to_method(mx.context)
-
-            if not var.is_staticmethod:
-                # Class-level function objects and classmethods become bound methods:
-                # the former to the instance, the latter to the class.
-                functype: FunctionLike = call_type
-                signature = freshen_all_functions_type_vars(functype)
-                bound = get_proper_type(expand_self_type(var, signature, mx.original_type))
-                assert isinstance(bound, FunctionLike)
-                signature = bound
-                signature = check_self_arg(
-                    signature, mx.self_type, var.is_classmethod, mx.context, name, mx.msg
-                )
-                signature = bind_self(signature, mx.self_type, var.is_classmethod)
-                expanded_signature = expand_type_by_instance(signature, itype)
-                freeze_all_type_vars(expanded_signature)
-                if var.is_property:
-                    # A property cannot have an overloaded type => the cast is fine.
-                    assert isinstance(expanded_signature, CallableType)
-                    if var.is_settable_property and mx.is_lvalue and var.setter_type is not None:
-                        # TODO: use check_call() to infer better type, same as for __set__().
-                        result = expanded_signature.arg_types[0]
-                    else:
-                        result = expanded_signature.ret_type
+            if mx.is_lvalue and not var.is_property and not mx.suppress_errors:
+                mx.msg.cant_assign_to_method(mx.context)
+
+        # Bind the self type for each callable component (when needed).
+        if call_type and not var.is_staticmethod:
+            bound_items = []
+            for ct in call_type.items if isinstance(call_type, UnionType) else [call_type]:
+                p_ct = get_proper_type(ct)
+                if isinstance(p_ct, FunctionLike) and not p_ct.is_type_obj():
+                    item = expand_and_bind_callable(p_ct, var, itype, name, mx)
                 else:
-                    result = expanded_signature
+                    item = expand_without_binding(ct, var, itype, original_itype, mx)
+                bound_items.append(item)
+            result = UnionType.make_union(bound_items)
     else:
         if not var.is_ready and not mx.no_deferral:
             mx.not_ready_callback(var.name, mx.context)
@@ -939,6 +927,37 @@ def analyze_var(
     return result
 
 
+def expand_without_binding(
+    typ: Type, var: Var, itype: Instance, original_itype: Instance, mx: MemberContext
+) -> Type:
+    typ = freshen_all_functions_type_vars(typ)
+    typ = expand_self_type_if_needed(typ, mx, var, original_itype)
+    expanded = expand_type_by_instance(typ, itype)
+    freeze_all_type_vars(expanded)
+    return expanded
+
+
+def expand_and_bind_callable(
+    functype: FunctionLike, var: Var, itype: Instance, name: str, mx: MemberContext
+) -> Type:
+    functype = freshen_all_functions_type_vars(functype)
+    typ = get_proper_type(expand_self_type(var, functype, mx.original_type))
+    assert isinstance(typ, FunctionLike)
+    typ = check_self_arg(typ, mx.self_type, var.is_classmethod, mx.context, name, mx.msg)
+    typ = bind_self(typ, mx.self_type, var.is_classmethod)
+    expanded = expand_type_by_instance(typ, itype)
+    freeze_all_type_vars(expanded)
+    if not var.is_property:
+        return expanded
+    # TODO: a decorated property can result in Overloaded here.
+    assert isinstance(expanded, CallableType)
+    if var.is_settable_property and mx.is_lvalue and var.setter_type is not None:
+        # TODO: use check_call() to infer better type, same as for __set__().
+        return expanded.arg_types[0]
+    else:
+        return expanded.ret_type
+
+
 def expand_self_type_if_needed(
     t: Type, mx: MemberContext, var: Var, itype: Instance, is_class: bool = False
 ) -> Type:
@@ -1018,7 +1037,16 @@ def f(self: S) -> T: ...
             selfarg = get_proper_type(item.arg_types[0])
             # This level of erasure matches the one in checker.check_func_def(),
             # better keep these two checks consistent.
-            if subtypes.is_subtype(dispatched_arg_type, erase_typevars(erase_to_bound(selfarg))):
+            if subtypes.is_subtype(
+                dispatched_arg_type,
+                erase_typevars(erase_to_bound(selfarg)),
+                # This is to work around the fact that erased ParamSpec and TypeVarTuple
+                # callables are not always compatible with non-erased ones both ways.
+                always_covariant=any(
+                    not isinstance(tv, TypeVarType) for tv in get_all_type_vars(selfarg)
+                ),
+                ignore_pos_arg_names=True,
+            ):
                 new_items.append(item)
             elif isinstance(selfarg, ParamSpecType):
                 # TODO: This is not always right. What's the most reasonable thing to do here?
@@ -1151,6 +1179,7 @@ def analyze_class_attribute_access(
             def_vars = set(node.node.info.defn.type_vars)
             if not node.node.is_classvar and node.node.info.self_type:
                 def_vars.add(node.node.info.self_type)
+            # TODO: should we include ParamSpec etc. here (i.e. use get_all_type_vars)?
             typ_vars = set(get_type_vars(t))
             if def_vars & typ_vars:
                 # Exception: access on Type[...], including first argument of class methods is OK.
@@ -1392,6 +1421,6 @@ def analyze_decorator_or_funcbase_access(
     """
     if isinstance(defn, Decorator):
         return analyze_var(name, defn.var, itype, mx)
-    return bind_self(
-        function_type(defn, mx.chk.named_type("builtins.function")), original_type=mx.self_type
-    )
+    typ = function_type(defn, mx.chk.named_type("builtins.function"))
+    typ = check_self_arg(typ, mx.self_type, defn.is_class, mx.context, name, mx.msg)
+    return bind_self(typ, original_type=mx.self_type, is_classmethod=defn.is_class)

mypy/semanal.py

@@ -3464,8 +3464,9 @@ def record_special_form_lvalue(self, s: AssignmentStmt) -> None:
     def analyze_enum_assign(self, s: AssignmentStmt) -> bool:
         """Check if s defines an Enum."""
         if isinstance(s.rvalue, CallExpr) and isinstance(s.rvalue.analyzed, EnumCallExpr):
-            # Already analyzed enum -- nothing to do here.
-            return True
+            # This is an analyzed enum definition.
+            # It is valid iff it can be stored correctly, failures were already reported.
+            return self._is_single_name_assignment(s)
         return self.enum_call_analyzer.process_enum_call(s, self.is_func_scope())
 
     def analyze_namedtuple_assign(self, s: AssignmentStmt) -> bool:
@@ -3474,7 +3475,9 @@ def analyze_namedtuple_assign(self, s: AssignmentStmt) -> bool:
             if s.rvalue.analyzed.info.tuple_type and not has_placeholder(
                 s.rvalue.analyzed.info.tuple_type
             ):
-                return True  # This is a valid and analyzed named tuple definition, nothing to do here.
+                # This is an analyzed named tuple definition.
+                # It is valid iff it can be stored correctly, failures were already reported.
+                return self._is_single_name_assignment(s)
         if len(s.lvalues) != 1 or not isinstance(s.lvalues[0], (NameExpr, MemberExpr)):
             return False
         lvalue = s.lvalues[0]
@@ -3515,8 +3518,9 @@ def analyze_typeddict_assign(self, s: AssignmentStmt) -> bool:
             if s.rvalue.analyzed.info.typeddict_type and not has_placeholder(
                 s.rvalue.analyzed.info.typeddict_type
             ):
-                # This is a valid and analyzed typed dict definition, nothing to do here.
-                return True
+                # This is an analyzed typed dict definition.
+                # It is valid iff it can be stored correctly, failures were already reported.
+                return self._is_single_name_assignment(s)
         if len(s.lvalues) != 1 or not isinstance(s.lvalues[0], (NameExpr, MemberExpr)):
             return False
         lvalue = s.lvalues[0]
@@ -3540,6 +3544,9 @@ def analyze_typeddict_assign(self, s: AssignmentStmt) -> bool:
                 self.setup_alias_type_vars(defn)
             return True
 
+    def _is_single_name_assignment(self, s: AssignmentStmt) -> bool:
+        return len(s.lvalues) == 1 and isinstance(s.lvalues[0], NameExpr)
+
     def analyze_lvalues(self, s: AssignmentStmt) -> None:
         # We cannot use s.type, because analyze_simple_literal_type() will set it.
         explicit = s.unanalyzed_type is not None

runtests.py

@@ -65,6 +65,15 @@
         "-p",
         "mypyc",
     ],
+    # Type check setup.py as well
+    "self-packaging": [
+        executable,
+        "-m",
+        "mypy",
+        "--config-file",
+        "mypy_self_check.ini",
+        "setup.py",
+    ],
     # Lint
     "lint": ["pre-commit", "run", "--all-files"],
     # Fast test cases only (this is the bulk of the test suite)

setup.py

@@ -31,7 +31,7 @@ def is_list_of_setuptools_extension(items: list[Any]) -> TypeGuard[list[Extensio
     return all(isinstance(item, Extension) for item in items)
 
 
-def find_package_data(base, globs, root="mypy"):
+def find_package_data(base: str, globs: list[str], root: str = "mypy") -> list[str]:
     """Find all interesting data files, for setup(package_data=)
 
     Arguments:
@@ -52,13 +52,13 @@ def find_package_data(base, globs, root="mypy"):
 
 
 class CustomPythonBuild(build_py):
-    def pin_version(self):
+    def pin_version(self) -> None:
         path = os.path.join(self.build_lib, "mypy")
         self.mkpath(path)
         with open(os.path.join(path, "version.py"), "w") as stream:
             stream.write(f'__version__ = "{version}"\n')
 
-    def run(self):
+    def run(self) -> None:
         self.execute(self.pin_version, ())
         build_py.run(self)
 
@@ -153,10 +153,10 @@ def run(self):
         # our Appveyor builds run out of memory sometimes.
         multi_file=sys.platform == "win32" or force_multifile,
     )
-    assert is_list_of_setuptools_extension(ext_modules), "Expected mypycify to use setuptools"
 
 else:
     ext_modules = []
 
+assert is_list_of_setuptools_extension(ext_modules), "Expected mypycify to use setuptools"
 
 setup(version=version, ext_modules=ext_modules, cmdclass=cmdclass)

test-data/unit/check-classes.test

@@ -3135,7 +3135,8 @@ from typing import Any
 class Test:
     def __setattr__() -> None: ...  # E: Method must have at least one argument. Did you forget the "self" argument? # E: Invalid signature "Callable[[], None]" for "__setattr__"
 t = Test()
-t.crash = 'test'  # E: "Test" has no attribute "crash"
+t.crash = 'test'  # E: Attribute function "__setattr__" with type "Callable[[], None]" does not accept self argument \
+                  # E: "Test" has no attribute "crash"
 
 class A:
     def __setattr__(self): ...  # E: Invalid signature "Callable[[A], Any]" for "__setattr__"
@@ -8650,3 +8651,34 @@ class C(B):
     def meth(self) -> None:
         def cb() -> None:
             self.x: int = 1  # E: Incompatible types in assignment (expression has type "int", base class "B" defined the type as "str")
+
+[case testOverloadedDescriptorSelected]
+from typing import Generic, TypeVar, Any, overload
+
+T_co = TypeVar("T_co", covariant=True)
+class Field(Generic[T_co]):
+    @overload
+    def __get__(self: Field[bool], instance: None, owner: Any) -> BoolField: ...
+    @overload
+    def __get__(self: Field[int], instance: None, owner: Any) -> NumField: ...
+    @overload
+    def __get__(self: Field[Any], instance: None, owner: Any) -> AnyField[T_co]: ...
+    @overload
+    def __get__(self, instance: Any, owner: Any) -> T_co: ...
+
+    def __get__(self, instance: Any, owner: Any) -> Any:
+        pass
+
+class BoolField(Field[bool]): ...
+class NumField(Field[int]): ...
+class AnyField(Field[T_co]): ...
+class Custom: ...
+
+class Fields:
+    bool_f: Field[bool]
+    int_f: Field[int]
+    custom_f: Field[Custom]
+
+reveal_type(Fields.bool_f)  # N: Revealed type is "__main__.BoolField"
+reveal_type(Fields.int_f)  # N: Revealed type is "__main__.NumField"
+reveal_type(Fields.custom_f)  # N: Revealed type is "__main__.AnyField[__main__.Custom]"

test-data/unit/check-classvar.test

@@ -334,3 +334,12 @@ class C:
 c:C
 c.foo()  # E: Too few arguments \
          # N: "foo" is considered instance variable, to make it class variable use ClassVar[...]
+
+[case testClassVarUnionBoundOnInstance]
+from typing import Union, Callable, ClassVar
+
+class C:
+    def f(self) -> int: ...
+    g: ClassVar[Union[Callable[[C], int], int]] = f
+
+reveal_type(C().g)  # N: Revealed type is "Union[def () -> builtins.int, builtins.int]"

test-data/unit/check-enum.test

@@ -2512,3 +2512,15 @@ def list_vals(e: Type[T]) -> list[T]:
 
 reveal_type(list_vals(Choices))  # N: Revealed type is "builtins.list[__main__.Choices]"
 [builtins fixtures/enum.pyi]
+
+[case testEnumAsClassMemberNoCrash]
+# https://github.com/python/mypy/issues/18736
+from enum import Enum
+
+class Base:
+    def __init__(self, namespace: tuple[str, ...]) -> None:
+        # Not a bug: trigger defer
+        names = [name for name in namespace if fail]  # E: Name "fail" is not defined
+        self.o = Enum("o", names)  # E: Enum type as attribute is not supported \
+                                   # E: Second argument of Enum() must be string, tuple, list or dict literal for mypy to determine Enum members
+[builtins fixtures/tuple.pyi]