Merge branch 'master' into stubtest_context

Author: tungol

mypy/checkexpr.py

@@ -582,7 +582,10 @@ def visit_call_expr_inner(self, e: CallExpr, allow_none_return: bool = False) ->
                     and not node.node.no_args
                     and not (
                         isinstance(union_target := get_proper_type(node.node.target), UnionType)
-                        and union_target.uses_pep604_syntax
+                        and (
+                            union_target.uses_pep604_syntax
+                            or self.chk.options.python_version >= (3, 10)
+                        )
                     )
                 ):
                     self.msg.type_arguments_not_allowed(e)

mypy/checkpattern.py

@@ -539,12 +539,12 @@ def visit_class_pattern(self, o: ClassPattern) -> PatternType:
         #
         type_info = o.class_ref.node
         if type_info is None:
-            return PatternType(AnyType(TypeOfAny.from_error), AnyType(TypeOfAny.from_error), {})
-        if isinstance(type_info, TypeAlias) and not type_info.no_args:
+            typ: Type = AnyType(TypeOfAny.from_error)
+        elif isinstance(type_info, TypeAlias) and not type_info.no_args:
             self.msg.fail(message_registry.CLASS_PATTERN_GENERIC_TYPE_ALIAS, o)
             return self.early_non_match()
-        if isinstance(type_info, TypeInfo):
-            typ: Type = fill_typevars_with_any(type_info)
+        elif isinstance(type_info, TypeInfo):
+            typ = fill_typevars_with_any(type_info)
         elif isinstance(type_info, TypeAlias):
             typ = type_info.target
         elif (

mypy/stubtest.py

@@ -961,22 +961,36 @@ def from_overloadedfuncdef(stub: nodes.OverloadedFuncDef) -> Signature[nodes.Arg
         # For most dunder methods, just assume all args are positional-only
         assume_positional_only = is_dunder(stub.name, exclude_special=True)
 
-        all_args: dict[str, list[tuple[nodes.Argument, int]]] = {}
+        is_arg_pos_only: defaultdict[str, set[bool]] = defaultdict(set)
         for func in map(_resolve_funcitem_from_decorator, stub.items):
             assert func is not None, "Failed to resolve decorated overload"
             args = maybe_strip_cls(stub.name, func.arguments)
             for index, arg in enumerate(args):
-                # For positional-only args, we allow overloads to have different names for the same
-                # argument. To accomplish this, we just make up a fake index-based name.
-                name = (
-                    f"__{index}"
-                    if arg.variable.name.startswith("__")
+                if (
+                    arg.variable.name.startswith("__")
                     or arg.pos_only
                     or assume_positional_only
                     or arg.variable.name.strip("_") == "self"
                     or (index == 0 and arg.variable.name.strip("_") == "cls")
-                    else arg.variable.name
-                )
+                ):
+                    is_arg_pos_only[arg.variable.name].add(True)
+                else:
+                    is_arg_pos_only[arg.variable.name].add(False)
+
+        all_args: dict[str, list[tuple[nodes.Argument, int]]] = {}
+        for func in map(_resolve_funcitem_from_decorator, stub.items):
+            assert func is not None, "Failed to resolve decorated overload"
+            args = maybe_strip_cls(stub.name, func.arguments)
+            for index, arg in enumerate(args):
+                # For positional-only args, we allow overloads to have different names for the same
+                # argument. To accomplish this, we just make up a fake index-based name.
+                # We can only use the index-based name if the argument is always
+                # positional only. Sometimes overloads have an arg as positional-only
+                # in some but not all branches of the overload.
+                name = arg.variable.name
+                if is_arg_pos_only[name] == {True}:
+                    name = f"__{index}"
+
                 all_args.setdefault(name, []).append((arg, index))
 
         def get_position(arg_name: str) -> int:

mypy/test/teststubtest.py

@@ -13,7 +13,11 @@
 from typing import Any, Callable
 
 import mypy.stubtest
+from mypy import build, nodes
+from mypy.modulefinder import BuildSource
+from mypy.options import Options
 from mypy.stubtest import parse_options, test_stubs
+from mypy.test.config import test_temp_dir
 from mypy.test.data import root_dir
 
 
@@ -158,6 +162,14 @@ def __invert__(self: _T) -> _T: pass
 """
 
 
+def build_helper(source: str) -> build.BuildResult:
+    return build.build(
+        sources=[BuildSource("main.pyi", None, textwrap.dedent(source))],
+        options=Options(),
+        alt_lib_path=test_temp_dir,
+    )
+
+
 def run_stubtest_with_stderr(
     stub: str, runtime: str, options: list[str], config_file: str | None = None
 ) -> tuple[str, str]:
@@ -842,6 +854,18 @@ def f2(self, *a) -> int: ...
             """,
             error=None,
         )
+        yield Case(
+            stub="""
+            @overload
+            def f(a: int) -> int: ...
+            @overload
+            def f(a: int, b: str, /) -> str: ...
+            """,
+            runtime="""
+            def f(a, *args): ...
+            """,
+            error=None,
+        )
 
     @collect_cases
     def test_property(self) -> Iterator[Case]:
@@ -2815,6 +2839,25 @@ def test_builtin_signature_with_unrepresentable_default(self) -> None:
             == "def (self, sep = ..., bytes_per_sep = ...)"
         )
 
+    def test_overload_signature(self) -> None:
+        # The same argument as both positional-only and pos-or-kw in
+        # different overloads previously produced incorrect signatures
+        source = """
+        from typing import overload
+        @overload
+        def myfunction(arg: int) -> None: ...
+        @overload
+        def myfunction(arg: str, /) -> None: ...
+        """
+        result = build_helper(source)
+        stub = result.files["__main__"].names["myfunction"].node
+        assert isinstance(stub, nodes.OverloadedFuncDef)
+        sig = mypy.stubtest.Signature.from_overloadedfuncdef(stub)
+        if sys.version_info >= (3, 10):
+            assert str(sig) == "def (arg: builtins.int | builtins.str)"
+        else:
+            assert str(sig) == "def (arg: Union[builtins.int, builtins.str])"
+
     def test_config_file(self) -> None:
         runtime = "temp = 5\n"
         stub = "from decimal import Decimal\ntemp: Decimal\n"

test-data/unit/check-python310.test

@@ -721,13 +721,14 @@ m: object
 match m:
     case xyz(y):  # E: Name "xyz" is not defined
         reveal_type(m)  # N: Revealed type is "Any"
-        reveal_type(y)  # E: Cannot determine type of "y" \
-                        # N: Revealed type is "Any"
+        reveal_type(y)  # N: Revealed type is "Any"
 
 match m:
     case xyz(z=x):  # E: Name "xyz" is not defined
-        reveal_type(x)  # E: Cannot determine type of "x" \
-                        # N: Revealed type is "Any"
+        reveal_type(x)  # N: Revealed type is "Any"
+    case (xyz1() as n) | (xyz2(attr=n)):  # E: Name "xyz1" is not defined \
+                                          # E: Name "xyz2" is not defined
+        reveal_type(n)  # N: Revealed type is "Any"
 
 [case testMatchClassPatternCaptureDataclass]
 from dataclasses import dataclass

test-data/unit/check-unions.test

@@ -1345,3 +1345,30 @@ x: Union[C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11]
 y: Union[C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, None]
 x = y  # E: Incompatible types in assignment (expression has type "Union[C1, C2, C3, C4, C5, <6 more items>, None]", variable has type "Union[C1, C2, C3, C4, C5, <6 more items>]") \
        # N: Item in the first union not in the second: "None"
+
+[case testTypeAliasWithOldUnionIsInstance]
+# flags: --python-version 3.10
+from typing import Union
+SimpleAlias = Union[int, str]
+
+def foo(x: Union[int, str, tuple]):
+    # TODO: fix the typeshed stub for isinstance
+    if isinstance(x, SimpleAlias):  # E: Argument 2 to "isinstance" has incompatible type "<typing special form>"; expected "type"
+        reveal_type(x)  # N: Revealed type is "Union[builtins.int, builtins.str, builtins.tuple[Any, ...]]"
+    else:
+        reveal_type(x)  # N: Revealed type is "Union[builtins.int, builtins.str, builtins.tuple[Any, ...]]"
+[builtins fixtures/tuple.pyi]
+
+
+[case testTypeAliasWithOldUnionIsInstancePython39]
+# flags: --python-version 3.9
+from typing import Union
+SimpleAlias = Union[int, str]
+
+def foo(x: Union[int, str, tuple]):
+    if isinstance(x, SimpleAlias):  # E: Parameterized generics cannot be used with class or instance checks \
+                                    # E: Argument 2 to "isinstance" has incompatible type "<typing special form>"; expected "type"
+        reveal_type(x)  # N: Revealed type is "Union[builtins.int, builtins.str, builtins.tuple[Any, ...]]"
+    else:
+        reveal_type(x)  # N: Revealed type is "Union[builtins.int, builtins.str, builtins.tuple[Any, ...]]"
+[builtins fixtures/tuple.pyi]