Merge branch 'master' into fix-isinstance-native-interpreted-subclass

Author: BobTheBuidler

.github/workflows/mypy_primer.yml

@@ -39,7 +39,7 @@ jobs:
           persist-credentials: false
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.13"
+          python-version: "3.14"
       - name: Install dependencies
         run: |
           python -m pip install -U pip

.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
@@ -65,6 +59,12 @@ jobs:
           toxenv: py
           tox_extra_args: "-n 4"
           test_mypyc: true
+        - name: Test suite with py314t-ubuntu, mypyc-compiled
+          python: '3.14t'
+          os: ubuntu-24.04-arm
+          toxenv: py
+          tox_extra_args: "-n 4"
+          test_mypyc: true
         - name: Test suite with py314-windows-64
           python: '3.14'
           os: windows-latest
@@ -101,12 +101,24 @@ jobs:
         #   tox_extra_args: "-n 4 mypyc/test/test_run.py mypyc/test/test_external.py"
         #   debug_build: true
 
-        - name: Type check our own code (py39-ubuntu)
-          python: '3.9'
+        - name: Parallel tests with py314-ubuntu, interpreted
+          python: '3.14'
+          os: ubuntu-24.04-arm
+          toxenv: py
+          tox_extra_args: "-n 4 --mypy-num-workers=4 mypy/test/testcheck.py"
+        - name: Parallel tests with py314-ubuntu, mypyc-compiled
+          python: '3.14'
+          os: ubuntu-24.04-arm
+          toxenv: py
+          tox_extra_args: "-n 4 --mypy-num-workers=4 mypy/test/testcheck.py"
+          test_mypyc: true
+
+        - 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

@@ -135,7 +135,7 @@ Type annotations can be added as follows:
 
 .. code-block:: python
 
-    import attr
+    import attrs
 
     @attrs.define
     class A:

docs/source/additional_features.rst

@@ -537,13 +537,15 @@ potentially problematic or redundant in some way.
                 print(x + "bad")
 
     To help prevent mypy from generating spurious warnings, the "Statement is
-    unreachable" warning will be silenced in exactly two cases:
+    unreachable" warning will be silenced in exactly three cases:
 
     1.  When the unreachable statement is a ``raise`` statement, is an
         ``assert False`` statement, or calls a function that has the :py:data:`~typing.NoReturn`
         return type hint. In other words, when the unreachable statement
         throws an error or terminates the program in some way.
-    2.  When the unreachable statement was *intentionally* marked as unreachable
+    2.  When the unreachable statement is ``return NotImplemented``. This
+        is allowed by mypy due to its use in operator overloading.
+    3.  When the unreachable statement was *intentionally* marked as unreachable
         using :ref:`version_and_platform_checks`.
 
     .. note::
@@ -958,12 +960,6 @@ in error messages.
     useful or they may be overly noisy. If ``N`` is negative, there is
     no limit. The default limit is -1.
 
-.. option:: --force-union-syntax
-
-    Always use ``Union[]`` and ``Optional[]`` for union types
-    in error messages (instead of the ``|`` operator),
-    even on Python 3.10+.
-
 
 .. _incremental:
 

docs/source/command_line.rst

@@ -930,15 +930,6 @@ These options may only be set in the global section (``[mypy]``).
 
     Show absolute paths to files.
 
-.. confval:: force_union_syntax
-
-    :type: boolean
-    :default: False
-
-    Always use ``Union[]`` and ``Optional[]`` for union types
-    in error messages (instead of the ``|`` operator),
-    even on Python 3.10+.
-
 Incremental mode
 ****************
 

docs/source/config_file.rst

@@ -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]
@@ -1129,6 +1151,25 @@ Warn about cases where a bytes object may be converted to a string in an unexpec
     print(f"The alphabet starts with {b!r}")  # The alphabet starts with b'abc'
     print(f"The alphabet starts with {b.decode('utf-8')}")  # The alphabet starts with abc
 
+.. _code-str-unpack:
+
+Check that ``str`` is not unpacked [str-unpack]
+---------------------------------------------------------
+
+It can sometimes be surprising that ``str`` is iterable, especially when unpacking
+in an assignment.
+
+Example:
+
+.. code-block:: python
+
+    def print_dict(d: dict[str, str]) -> int:
+        # We meant to do d.items(), but instead we're unpacking the str keys of d
+
+        # Error: Unpacking a string is disallowed
+        for k, v in d:
+            print(k, v)
+
 .. _code-overload-overlap:
 
 Check that overloaded functions don't overlap [overload-overlap]

docs/source/error_code_list.rst

@@ -32,7 +32,7 @@ Example:
 
     # mypy: disallow-any-generics
 
-    # Error: Missing type parameters for generic type "list"  [type-arg]
+    # Error: Missing type arguments for generic type "list"  [type-arg]
     def remove_dups(items: list) -> list:
         ...