Merge branch 'master' into special_case_typeddict_get

Author: randolf-scholz

.pre-commit-config.yaml

@@ -41,7 +41,7 @@ repos:
           # actionlint has a shellcheck integration which extracts shell scripts in `run:` steps from GitHub Actions
           # and checks these with shellcheck. This is arguably its most useful feature,
           # but the integration only works if shellcheck is installed
-          - "github.com/wasilibs/go-shellcheck/cmd/shellcheck@v0.10.0"
+          - "github.com/wasilibs/go-shellcheck/cmd/shellcheck@v0.11.0"
   - repo: https://github.com/woodruffw/zizmor-pre-commit
     rev: v1.5.2
     hooks:

docs/source/error_code_list2.rst

@@ -676,3 +676,26 @@ Example:
                 print("red")
             case _:
                 print("other")
+
+.. _code-untyped-decorator:
+
+Error if an untyped decorator makes a typed function effectively untyped [untyped-decorator]
+--------------------------------------------------------------------------------------------
+
+If enabled with :option:`--disallow-untyped-decorators <mypy --disallow-untyped-decorators>`
+mypy generates an error if a typed function is wrapped by an untyped decorator
+(as this would effectively remove the benefits of typing the function).
+
+Example:
+
+.. code-block:: python
+
+        def printing_decorator(func):
+            def wrapper(*args, **kwds):
+                print("Calling", func)
+                return func(*args, **kwds)
+            return wrapper
+        # A decorated function.
+        @printing_decorator  # E: Untyped decorator makes function "add_forty_two" untyped  [untyped-decorator]
+        def add_forty_two(value: int) -> int:
+            return value + 42

docs/source/stubtest.rst

@@ -99,8 +99,75 @@ to mypy build errors". In this case, you will need to mitigate those errors
 before stubtest will run. Despite potential overlap in errors here, stubtest is
 not intended as a substitute for running mypy directly.
 
+Allowlist
+*********
+
 If you wish to ignore some of stubtest's complaints, stubtest supports a
-pretty handy allowlist system.
+pretty handy :option:`--allowlist` system.
+
+Let's say that you have this python module called ``ex``:
+
+.. code-block:: python
+
+   try:
+       import optional_expensive_dep
+   except ImportError:
+       optional_expensive_dep = None
+
+   first = 1
+   if optional_expensive_dep:
+       second = 2
+
+Let's say that you can't install ``optional_expensive_dep`` in CI for some reason,
+but you still want to include ``second: int`` in the stub file:
+
+.. code-block:: python
+
+    first: int
+    second: int
+
+In this case stubtest will correctly complain:
+
+.. code-block:: shell
+
+   error: ex.second is not present at runtime
+   Stub: in file /.../ex.pyi:2
+   builtins.int
+   Runtime:
+   MISSING
+
+   Found 1 error (checked 1 module)
+
+To fix this, you can add an ``allowlist`` entry:
+
+.. code-block:: ini
+
+   # Allowlist entries in `allowlist.txt` file:
+
+   # Does not exist if `optional_expensive_dep` is not installed:
+   ex.second
+
+And now when running stubtest with ``--allowlist=allowlist.txt``,
+no errors will be generated anymore.
+
+Allowlists also support regular expressions,
+which can be useful to ignore many similar errors at once.
+They can also be useful for suppressing stubtest errors that occur sometimes,
+but not on every CI run. For example, if some CI workers have
+``optional_expensive_dep`` installed, stubtest might complain with this message
+on those workers if you had the ``ex.second`` allowlist entry:
+
+.. code-block:: ini
+
+   note: unused allowlist entry ex.second
+   Found 1 error (checked 1 module)
+
+Changing ``ex.second`` to be ``(ex\.second)?`` will make this error optional,
+meaning that stubtest will pass whether or not a CI runner
+has``optional_expensive_dep`` installed.
+
+CLI
+***
 
 The rest of this section documents the command line interface of stubtest.
 
@@ -119,15 +186,15 @@ The rest of this section documents the command line interface of stubtest.
 .. option:: --allowlist FILE
 
     Use file as an allowlist. Can be passed multiple times to combine multiple
-    allowlists. Allowlists can be created with --generate-allowlist. Allowlists
-    support regular expressions.
+    allowlists. Allowlists can be created with :option:`--generate-allowlist`.
+    Allowlists support regular expressions.
 
     The presence of an entry in the allowlist means stubtest will not generate
     any errors for the corresponding definition.
 
 .. option:: --generate-allowlist
 
-    Print an allowlist (to stdout) to be used with --allowlist
+    Print an allowlist (to stdout) to be used with :option:`--allowlist`.
 
     When introducing stubtest to an existing project, this is an easy way to
     silence all existing errors.
@@ -141,17 +208,17 @@ The rest of this section documents the command line interface of stubtest.
 
     Note if an allowlist entry is a regex that matches the empty string,
     stubtest will never consider it unused. For example, to get
-    `--ignore-unused-allowlist` behaviour for a single allowlist entry like
+    ``--ignore-unused-allowlist`` behaviour for a single allowlist entry like
     ``foo.bar`` you could add an allowlist entry ``(foo\.bar)?``.
     This can be useful when an error only occurs on a specific platform.
 
 .. option:: --mypy-config-file FILE
 
-    Use specified mypy config file to determine mypy plugins and mypy path
+    Use specified mypy config *file* to determine mypy plugins and mypy path
 
 .. option:: --custom-typeshed-dir DIR
 
-    Use the custom typeshed in DIR
+    Use the custom typeshed in *DIR*
 
 .. option:: --check-typeshed
 

mypy-requirements.txt

@@ -4,4 +4,4 @@ typing_extensions>=4.6.0
 mypy_extensions>=1.0.0
 pathspec>=0.9.0
 tomli>=1.1.0; python_version<'3.11'
-librt>=0.1.0
+librt>=0.2.1

mypy/cache.py

@@ -3,8 +3,7 @@
 from collections.abc import Sequence
 from typing import Final
 
-from mypy_extensions import u8
-from native_internal import (
+from librt.internal import (
     Buffer as Buffer,
     read_bool as read_bool,
     read_float as read_float,
@@ -17,6 +16,7 @@
     write_str as write_str,
     write_tag as write_tag,
 )
+from mypy_extensions import u8
 
 # Always use this type alias to refer to type tags.
 Tag = u8

mypy/checkpattern.py

@@ -14,7 +14,7 @@
 from mypy.maptype import map_instance_to_supertype
 from mypy.meet import narrow_declared_type
 from mypy.messages import MessageBuilder
-from mypy.nodes import ARG_POS, Context, Expression, NameExpr, TypeAlias, TypeInfo, Var
+from mypy.nodes import ARG_POS, Context, Expression, NameExpr, TypeAlias, Var
 from mypy.options import Options
 from mypy.patterns import (
     AsPattern,
@@ -37,6 +37,7 @@
 )
 from mypy.types import (
     AnyType,
+    FunctionLike,
     Instance,
     LiteralType,
     NoneType,
@@ -538,27 +539,20 @@ def visit_class_pattern(self, o: ClassPattern) -> PatternType:
         # Check class type
         #
         type_info = o.class_ref.node
-        if type_info is None:
-            typ: Type = AnyType(TypeOfAny.from_error)
-        elif isinstance(type_info, TypeAlias) and not type_info.no_args:
+        typ = self.chk.expr_checker.accept(o.class_ref)
+        p_typ = get_proper_type(typ)
+        if 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()
-        elif isinstance(type_info, TypeInfo):
-            typ = fill_typevars_with_any(type_info)
-        elif isinstance(type_info, TypeAlias):
-            typ = type_info.target
-        elif (
-            isinstance(type_info, Var)
-            and type_info.type is not None
-            and isinstance(get_proper_type(type_info.type), AnyType)
-        ):
-            typ = type_info.type
-        else:
-            if isinstance(type_info, Var) and type_info.type is not None:
-                name = type_info.type.str_with_options(self.options)
-            else:
-                name = type_info.name
-            self.msg.fail(message_registry.CLASS_PATTERN_TYPE_REQUIRED.format(name), o)
+        elif isinstance(p_typ, FunctionLike) and p_typ.is_type_obj():
+            typ = fill_typevars_with_any(p_typ.type_object())
+        elif not isinstance(p_typ, AnyType):
+            self.msg.fail(
+                message_registry.CLASS_PATTERN_TYPE_REQUIRED.format(
+                    typ.str_with_options(self.options)
+                ),
+                o,
+            )
             return self.early_non_match()
 
         new_type, rest_type = self.chk.conditional_types_with_intersection(
@@ -697,6 +691,8 @@ def should_self_match(self, typ: Type) -> bool:
         typ = get_proper_type(typ)
         if isinstance(typ, TupleType):
             typ = typ.partial_fallback
+        if isinstance(typ, AnyType):
+            return False
         if isinstance(typ, Instance) and typ.type.get("__match_args__") is not None:
             # Named tuples and other subtypes of builtins that define __match_args__
             # should not self match.

mypy/errorcodes.py

@@ -302,6 +302,10 @@ def __hash__(self) -> int:
     sub_code_of=MISC,
 )
 
+UNTYPED_DECORATOR: Final = ErrorCode(
+    "untyped-decorator", "Error if an untyped decorator makes a typed function untyped", "General"
+)
+
 NARROWED_TYPE_NOT_SUBTYPE: Final = ErrorCode(
     "narrowed-type-not-subtype",
     "Warn if a TypeIs function's narrowed type is not a subtype of the original type",

mypy/errors.py

@@ -806,8 +806,8 @@ def generate_unused_ignore_errors(self, file: str) -> None:
                 continue
             if codes.UNUSED_IGNORE.code in ignored_codes:
                 continue
-            used_ignored_codes = used_ignored_lines[line]
-            unused_ignored_codes = set(ignored_codes) - set(used_ignored_codes)
+            used_ignored_codes = set(used_ignored_lines[line])
+            unused_ignored_codes = [c for c in ignored_codes if c not in used_ignored_codes]
             # `ignore` is used
             if not ignored_codes and used_ignored_codes:
                 continue
@@ -817,7 +817,7 @@ def generate_unused_ignore_errors(self, file: str) -> None:
             # Display detail only when `ignore[...]` specifies more than one error code
             unused_codes_message = ""
             if len(ignored_codes) > 1 and unused_ignored_codes:
-                unused_codes_message = f"[{', '.join(sorted(unused_ignored_codes))}]"
+                unused_codes_message = f"[{', '.join(unused_ignored_codes)}]"
             message = f'Unused "type: ignore{unused_codes_message}" comment'
             for unused in unused_ignored_codes:
                 narrower = set(used_ignored_codes) & codes.sub_code_map[unused]

mypy/fastparse.py

@@ -232,9 +232,12 @@ def parse(
         assert options.python_version[0] >= 3
         feature_version = options.python_version[1]
     try:
-        # Disable deprecation warnings about \u
+        # Disable
+        # - deprecation warnings for 'invalid escape sequence' (Python 3.11 and below)
+        # - syntax warnings for 'invalid escape sequence' (3.12+) and 'return in finally' (3.14+)
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", category=DeprecationWarning)
+            warnings.filterwarnings("ignore", category=SyntaxWarning)
             ast = ast3_parse(source, fnam, "exec", feature_version=feature_version)
 
         tree = ASTConverter(

mypy/messages.py

@@ -2008,7 +2008,11 @@ def untyped_decorated_function(self, typ: Type, context: Context) -> None:
             )
 
     def typed_function_untyped_decorator(self, func_name: str, context: Context) -> None:
-        self.fail(f'Untyped decorator makes function "{func_name}" untyped', context)
+        self.fail(
+            f'Untyped decorator makes function "{func_name}" untyped',
+            context,
+            code=codes.UNTYPED_DECORATOR,
+        )
 
     def bad_proto_variance(
         self, actual: int, tvar_name: str, expected: int, context: Context