Merge remote-tracking branch 'upstream/master' into simple-parallel

Author: ilevkivskyi

.github/workflows/test.yml

@@ -31,28 +31,22 @@ jobs:
         include:
         # Make sure to run mypyc compiled unit tests for both
         # the oldest and newest supported Python versions
-        - name: Test suite with py39-ubuntu, mypyc-compiled
-          python: '3.9'
-          os: ubuntu-24.04-arm
-          toxenv: py
-          tox_extra_args: "-n 4"
-          test_mypyc: true
-        - name: Test suite with py310-ubuntu
+        - name: Test suite with py310-ubuntu, mypyc-compiled
           python: '3.10'
           os: ubuntu-24.04-arm
           toxenv: py
           tox_extra_args: "-n 4"
+          test_mypyc: true
         - name: Test suite with py311-ubuntu
           python: '3.11'
           os: ubuntu-24.04-arm
           toxenv: py
           tox_extra_args: "-n 4"
-        - name: Test suite with py312-ubuntu, mypyc-compiled
+        - name: Test suite with py312-ubuntu
           python: '3.12'
           os: ubuntu-24.04-arm
           toxenv: py
           tox_extra_args: "-n 4"
-          test_mypyc: true
         - name: Test suite with py313-ubuntu, mypyc-compiled
           python: '3.13'
           os: ubuntu-24.04-arm
@@ -113,12 +107,12 @@ jobs:
           tox_extra_args: "-n 4 --mypy-num-workers=4 mypy/test/testcheck.py"
           test_mypyc: true
 
-        - name: Type check our own code (py39-ubuntu)
-          python: '3.9'
+        - name: Type check our own code (py310-ubuntu)
+          python: '3.10'
           os: ubuntu-latest
           toxenv: type
-        - name: Type check our own code (py39-windows-64)
-          python: '3.9'
+        - name: Type check our own code (py310-windows-64)
+          python: '3.10'
           os: windows-latest
           toxenv: type
 

.github/workflows/test_stubgenc.yml

@@ -32,10 +32,10 @@ jobs:
       with:
         persist-credentials: false
 
-    - name: Setup 🐍 3.9
+    - name: Setup 🐍 3.10
       uses: actions/setup-python@v5
       with:
-        python-version: 3.9
+        python-version: '3.10'
 
     - name: Test stubgenc
       run: misc/test-stubgenc.sh

CHANGELOG.md

@@ -51,7 +51,7 @@ hash -r  # This resets shell PATH cache, not necessary on Windows
 ```
 
 > **Note**
-> You'll need Python 3.9 or higher to install all requirements listed in
+> You'll need Python 3.10 or higher to install all requirements listed in
 > test-requirements.txt
 
 ### Running tests

CONTRIBUTING.md

@@ -215,6 +215,28 @@ You can use :py:class:`~collections.abc.Callable` as the type for callable objec
         for x in objs:
             f(x)
 
+.. _code-nonetype-type:
+
+Check that NoneType is not used as a type (annotation) [nonetype-type]
+----------------------------------------------------------------------
+
+The preferred way to annotate the type of `None` is `None`.
+`NoneType` is equivalent, but mypy won't allow it by default.
+
+.. code-block:: python
+
+    from types import NoneType
+    def f(x: None) -> None:
+        reveal_type(x) # note: Revealed type is "None"
+
+    # error: NoneType should not be used as a type, please use None instead  [nonetype-type]
+    def g(x: NoneType) -> None:
+        reveal_type(x) # note: Revealed type is "None"
+
+    # error: NoneType should not be used as a type, please use None instead  [nonetype-type]
+    x1: NoneType = None
+    x2: None = None # OK
+
 .. _code-metaclass:
 
 Check the validity of a class's metaclass [metaclass]

docs/source/error_code_list.rst

@@ -16,7 +16,7 @@ may not make much sense otherwise.
 Installing and running mypy
 ***************************
 
-Mypy requires Python 3.9 or later to run.  You can install mypy using pip:
+Mypy requires Python 3.10 or later to run.  You can install mypy using pip:
 
 .. code-block:: shell
 

docs/source/getting_started.rst

@@ -36,8 +36,8 @@ def map_actuals_to_formals(
     The result contains a list of caller argument indexes mapping to each
     callee argument index, indexed by callee index.
 
-    The caller_arg_type argument should evaluate to the type of the actual
-    argument type with the given index.
+    The actual_arg_type argument should evaluate to the type of the actual
+    argument with the given index.
     """
     nformals = len(formal_kinds)
     formal_to_actual: list[list[int]] = [[] for i in range(nformals)]

mypy/argmap.py

@@ -3,7 +3,7 @@
 from collections import defaultdict
 from collections.abc import Iterator
 from contextlib import contextmanager
-from typing import NamedTuple, Optional, Union
+from typing import NamedTuple
 from typing_extensions import TypeAlias as _TypeAlias
 
 from mypy.erasetype import remove_instance_last_known_values
@@ -39,7 +39,7 @@
 )
 from mypy.typevars import fill_typevars_with_any
 
-BindableExpression: _TypeAlias = Union[IndexExpr, MemberExpr, NameExpr]
+BindableExpression: _TypeAlias = IndexExpr | MemberExpr | NameExpr
 
 
 class CurrentType(NamedTuple):
@@ -81,7 +81,7 @@ def __repr__(self) -> str:
         return f"Frame({self.id}, {self.types}, {self.unreachable}, {self.conditional_frame})"
 
 
-Assigns = defaultdict[Expression, list[tuple[Type, Optional[Type]]]]
+Assigns = defaultdict[Expression, list[tuple[Type, Type | None]]]
 
 
 class ConditionalTypeBinder:

mypy/binder.py

@@ -48,7 +48,7 @@
 from __future__ import annotations
 
 from collections.abc import Sequence
-from typing import Any, Final, Union
+from typing import Any, Final
 from typing_extensions import TypeAlias as _TypeAlias
 
 from librt.internal import (
@@ -391,10 +391,8 @@ def write_str_opt_list(data: WriteBuffer, value: list[str | None]) -> None:
         write_str_opt(data, item)
 
 
-JsonValue: _TypeAlias = Union[None, int, str, bool, list["JsonValue"], dict[str, "JsonValue"]]
-JsonValueEx: _TypeAlias = Union[
-    None, int, str, bool, list["JsonValueEx"], dict[str, "JsonValueEx"], tuple["JsonValueEx", ...]
-]
+JsonValue: _TypeAlias = None | int | str | bool | list["JsonValue"] | dict[str, "JsonValue"]
+JsonValueEx: _TypeAlias = None | int | str | bool | list["JsonValueEx"] | dict[str, "JsonValueEx"] | tuple["JsonValueEx", ...]
 
 
 def read_json_value(data: ReadBuffer) -> JsonValue:

mypy/cache.py

@@ -6,18 +6,7 @@
 from collections import defaultdict
 from collections.abc import Iterable, Iterator, Mapping, Sequence, Set as AbstractSet
 from contextlib import ExitStack, contextmanager
-from typing import (
-    Callable,
-    Final,
-    Generic,
-    Literal,
-    NamedTuple,
-    Optional,
-    TypeVar,
-    Union,
-    cast,
-    overload,
-)
+from typing import Callable, Final, Generic, Literal, NamedTuple, TypeVar, cast, overload
 from typing_extensions import TypeAlias as _TypeAlias, TypeGuard
 
 import mypy.checkexpr
@@ -249,8 +238,8 @@
 # Maximum length of fixed tuple types inferred when narrowing from variadic tuples.
 MAX_PRECISE_TUPLE_SIZE: Final = 8
 
-DeferredNodeType: _TypeAlias = Union[FuncDef, OverloadedFuncDef, Decorator]
-FineGrainedDeferredNodeType: _TypeAlias = Union[FuncDef, MypyFile, OverloadedFuncDef]
+DeferredNodeType: _TypeAlias = FuncDef | OverloadedFuncDef | Decorator
+FineGrainedDeferredNodeType: _TypeAlias = FuncDef | MypyFile | OverloadedFuncDef
 
 
 # A node which is postponed to be processed during the next pass.
@@ -283,7 +272,7 @@ class FineGrainedDeferredNode(NamedTuple):
 # (such as two references to the same variable). TODO: it would
 # probably be better to have the dict keyed by the nodes' literal_hash
 # field instead.
-TypeMap: _TypeAlias = Optional[dict[Expression, Type]]
+TypeMap: _TypeAlias = dict[Expression, Type] | None
 
 
 # Keeps track of partial types in a single scope. In fine-grained incremental
@@ -5309,16 +5298,22 @@ def get_types_from_except_handler(self, typ: Type, n: Expression) -> list[Type]:
         """Helper for check_except_handler_test to retrieve handler types."""
         typ = get_proper_type(typ)
         if isinstance(typ, TupleType):
-            return typ.items
+            merged_type = make_simplified_union(typ.items)
+            if isinstance(merged_type, UnionType):
+                return merged_type.relevant_items()
+            return [merged_type]
+        elif is_named_instance(typ, "builtins.tuple"):
+            # variadic tuple
+            merged_type = make_simplified_union((typ.args[0],))
+            if isinstance(merged_type, UnionType):
+                return merged_type.relevant_items()
+            return [merged_type]
         elif isinstance(typ, UnionType):
             return [
                 union_typ
                 for item in typ.relevant_items()
                 for union_typ in self.get_types_from_except_handler(item, n)
             ]
-        elif is_named_instance(typ, "builtins.tuple"):
-            # variadic tuple
-            return [typ.args[0]]
         else:
             return [typ]