Merge branch 'master' into cli

Author: wyattscarpenter

CHANGELOG.md

@@ -2,9 +2,9 @@
 
 ## Next Release
 
-## Mypy 1.18
+## Mypy 1.18.1
 
-We’ve just uploaded mypy 1.18 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)).
+We’ve just uploaded mypy 1.18.1 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)).
 Mypy is a static type checker for Python. This release includes new features, performance
 improvements and bug fixes. You can install it as follows:
 
@@ -14,7 +14,7 @@ You can read the full documentation for this release on [Read the Docs](http://m
 
 ### Mypy Performance Improvements
 
-Mypy 1.18 includes numerous performance improvements, resulting in about 40% speedup
+Mypy 1.18.1 includes numerous performance improvements, resulting in about 40% speedup
 compared to 1.17 when type checking mypy itself. In extreme cases, the improvement
 can be 10x or higher. The list below is an overview of the various mypy optimizations.
 Many mypyc improvements (discussed in a separate section below) also improve performance.
@@ -283,6 +283,12 @@ Related PRs:
 
 Please see [git log](https://github.com/python/typeshed/commits/main?after=2480d7e7c74493a024eaf254c5d2c6f452c80ee2+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.
 
+### Mypy 1.18.2
+
+- Fix crash on recursive alias (Ivan Levkivskyi, PR [19845](https://github.com/python/mypy/pull/19845))
+- Add additional guidance for stubtest errors when runtime is `object.__init__` (Stephen Morton, PR [19733](https://github.com/python/mypy/pull/19733))
+- Fix handling of None values in f-string expressions in mypyc (BobTheBuidler, PR [19846](https://github.com/python/mypy/pull/19846))
+
 ### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:

docs/source/command_line.rst

@@ -1263,12 +1263,23 @@ Miscellaneous
    stub packages were found, they are installed and then another run
    is performed.
 
-.. option:: --junit-xml JUNIT_XML
+.. option:: --junit-xml JUNIT_XML_OUTPUT_FILE
 
     Causes mypy to generate a JUnit XML test result document with
     type checking results. This can make it easier to integrate mypy
     with continuous integration (CI) tools.
 
+.. option:: --junit-format {global,per_file}
+
+    If --junit-xml is set, specifies format.
+    global (default): single test with all errors;
+    per_file: one test entry per file with failures.
+
+.. option:: --find-occurrences CLASS.MEMBER
+
+    This flag will make mypy print out all usages of a class member
+    based on static type information. This feature is experimental.
+
 .. option:: --scripts-are-modules
 
     This flag will give command line arguments that appear to be

docs/source/config_file.rst

@@ -1153,6 +1153,15 @@ These options may only be set in the global section (``[mypy]``).
     type checking results. This can make it easier to integrate mypy
     with continuous integration (CI) tools.
 
+.. confval:: junit_format
+
+    :type: string
+    :default: ``global``
+
+    If junit_xml is set, specifies format.
+    global (default): single test with all errors;
+    per_file: one test entry per file with failures.
+
 .. confval:: scripts_are_modules
 
     :type: boolean

misc/analyze_cache.py

@@ -41,7 +41,7 @@ def extract(chunks: Iterable[JsonDict]) -> Iterable[JsonDict]:
             if isinstance(chunk, dict):
                 yield chunk
                 yield from extract(chunk.values())
-            elif isinstance(chunk, list):
+            elif isinstance(chunk, list):  # type: ignore[unreachable] #TODO: is this actually unreachable, or are our types wrong?
                 yield from extract(chunk)
 
     yield from extract([chunk.data for chunk in chunks])
@@ -93,7 +93,7 @@ def compress(chunk: JsonDict) -> JsonDict:
     def helper(chunk: JsonDict) -> JsonDict:
         nonlocal counter
         if not isinstance(chunk, dict):
-            return chunk
+            return chunk  # type: ignore[unreachable] #TODO: is this actually unreachable, or are our types wrong?
 
         if len(chunk) <= 2:
             return chunk
@@ -124,7 +124,7 @@ def decompress(chunk: JsonDict) -> JsonDict:
 
     def helper(chunk: JsonDict) -> JsonDict:
         if not isinstance(chunk, dict):
-            return chunk
+            return chunk  # type: ignore[unreachable] #TODO: is this actually unreachable, or are our types wrong?
         if ".id" in chunk:
             return cache[chunk[".id"]]
 

misc/profile_check.py

@@ -78,22 +78,22 @@ def check_requirements() -> None:
     if sys.platform != "linux":
         # TODO: How to make this work on other platforms?
         sys.exit("error: Only Linux is supported")
-
-    try:
-        subprocess.run(["perf", "-h"], capture_output=True)
-    except (subprocess.CalledProcessError, FileNotFoundError):
-        print("error: The 'perf' profiler is not installed")
-        sys.exit(1)
-
-    try:
-        subprocess.run(["clang", "--version"], capture_output=True)
-    except (subprocess.CalledProcessError, FileNotFoundError):
-        print("error: The clang compiler is not installed")
-        sys.exit(1)
-
-    if not os.path.isfile("mypy_self_check.ini"):
-        print("error: Run this in the mypy repository root")
-        sys.exit(1)
+    else:  # fun fact/todo: we have to use else here, because of https://github.com/python/mypy/issues/10773
+        try:
+            subprocess.run(["perf", "-h"], capture_output=True)
+        except (subprocess.CalledProcessError, FileNotFoundError):
+            print("error: The 'perf' profiler is not installed")
+            sys.exit(1)
+
+        try:
+            subprocess.run(["clang", "--version"], capture_output=True)
+        except (subprocess.CalledProcessError, FileNotFoundError):
+            print("error: The clang compiler is not installed")
+            sys.exit(1)
+
+        if not os.path.isfile("mypy_self_check.ini"):
+            print("error: Run this in the mypy repository root")
+            sys.exit(1)
 
 
 def main() -> None:

mypy/errorcodes.py

@@ -52,32 +52,28 @@ def __hash__(self) -> int:
 
 ATTR_DEFINED: Final = ErrorCode("attr-defined", "Check that attribute exists", "General")
 NAME_DEFINED: Final = ErrorCode("name-defined", "Check that name is defined", "General")
-CALL_ARG: Final[ErrorCode] = ErrorCode(
+CALL_ARG: Final = ErrorCode(
     "call-arg", "Check number, names and kinds of arguments in calls", "General"
 )
 ARG_TYPE: Final = ErrorCode("arg-type", "Check argument types in calls", "General")
 CALL_OVERLOAD: Final = ErrorCode(
     "call-overload", "Check that an overload variant matches arguments", "General"
 )
-VALID_TYPE: Final[ErrorCode] = ErrorCode(
-    "valid-type", "Check that type (annotation) is valid", "General"
-)
+VALID_TYPE: Final = ErrorCode("valid-type", "Check that type (annotation) is valid", "General")
 VAR_ANNOTATED: Final = ErrorCode(
     "var-annotated", "Require variable annotation if type can't be inferred", "General"
 )
 OVERRIDE: Final = ErrorCode(
     "override", "Check that method override is compatible with base class", "General"
 )
-RETURN: Final[ErrorCode] = ErrorCode(
-    "return", "Check that function always returns a value", "General"
-)
-RETURN_VALUE: Final[ErrorCode] = ErrorCode(
+RETURN: Final = ErrorCode("return", "Check that function always returns a value", "General")
+RETURN_VALUE: Final = ErrorCode(
     "return-value", "Check that return value is compatible with signature", "General"
 )
-ASSIGNMENT: Final[ErrorCode] = ErrorCode(
+ASSIGNMENT: Final = ErrorCode(
     "assignment", "Check that assigned value is compatible with target", "General"
 )
-METHOD_ASSIGN: Final[ErrorCode] = ErrorCode(
+METHOD_ASSIGN: Final = ErrorCode(
     "method-assign",
     "Check that assignment target is not a method",
     "General",
@@ -143,9 +139,7 @@ def __hash__(self) -> int:
 UNUSED_COROUTINE: Final = ErrorCode(
     "unused-coroutine", "Ensure that all coroutines are used", "General"
 )
-# TODO: why do we need the explicit type here? Without it mypyc CI builds fail with
-# mypy/message_registry.py:37: error: Cannot determine type of "EMPTY_BODY"  [has-type]
-EMPTY_BODY: Final[ErrorCode] = ErrorCode(
+EMPTY_BODY: Final = ErrorCode(
     "empty-body",
     "A dedicated error code to opt out return errors for empty/trivial bodies",
     "General",
@@ -160,7 +154,7 @@ def __hash__(self) -> int:
     "await-not-async", 'Warn about "await" outside coroutine ("async def")', "General"
 )
 # These error codes aren't enabled by default.
-NO_UNTYPED_DEF: Final[ErrorCode] = ErrorCode(
+NO_UNTYPED_DEF: Final = ErrorCode(
     "no-untyped-def", "Check that every function has an annotation", "General"
 )
 NO_UNTYPED_CALL: Final = ErrorCode(
@@ -186,13 +180,13 @@ def __hash__(self) -> int:
 UNREACHABLE: Final = ErrorCode(
     "unreachable", "Warn about unreachable statements or expressions", "General"
 )
-ANNOTATION_UNCHECKED = ErrorCode(
+ANNOTATION_UNCHECKED: Final = ErrorCode(
     "annotation-unchecked", "Notify about type annotations in unchecked functions", "General"
 )
-TYPEDDICT_READONLY_MUTATED = ErrorCode(
+TYPEDDICT_READONLY_MUTATED: Final = ErrorCode(
     "typeddict-readonly-mutated", "TypedDict's ReadOnly key is mutated", "General"
 )
-POSSIBLY_UNDEFINED: Final[ErrorCode] = ErrorCode(
+POSSIBLY_UNDEFINED: Final = ErrorCode(
     "possibly-undefined",
     "Warn about variables that are defined only in some execution paths",
     "General",
@@ -201,18 +195,18 @@ def __hash__(self) -> int:
 REDUNDANT_EXPR: Final = ErrorCode(
     "redundant-expr", "Warn about redundant expressions", "General", default_enabled=False
 )
-TRUTHY_BOOL: Final[ErrorCode] = ErrorCode(
+TRUTHY_BOOL: Final = ErrorCode(
     "truthy-bool",
     "Warn about expressions that could always evaluate to true in boolean contexts",
     "General",
     default_enabled=False,
 )
-TRUTHY_FUNCTION: Final[ErrorCode] = ErrorCode(
+TRUTHY_FUNCTION: Final = ErrorCode(
     "truthy-function",
     "Warn about function that always evaluate to true in boolean contexts",
     "General",
 )
-TRUTHY_ITERABLE: Final[ErrorCode] = ErrorCode(
+TRUTHY_ITERABLE: Final = ErrorCode(
     "truthy-iterable",
     "Warn about Iterable expressions that could always evaluate to true in boolean contexts",
     "General",
@@ -238,13 +232,13 @@ def __hash__(self) -> int:
     "General",
     default_enabled=False,
 )
-REDUNDANT_SELF_TYPE = ErrorCode(
+REDUNDANT_SELF_TYPE: Final = ErrorCode(
     "redundant-self",
     "Warn about redundant Self type annotations on method first argument",
     "General",
     default_enabled=False,
 )
-USED_BEFORE_DEF: Final[ErrorCode] = ErrorCode(
+USED_BEFORE_DEF: Final = ErrorCode(
     "used-before-def", "Warn about variables that are used before they are defined", "General"
 )
 UNUSED_IGNORE: Final = ErrorCode(
@@ -262,7 +256,7 @@ def __hash__(self) -> int:
     "General",
     default_enabled=False,
 )
-MUTABLE_OVERRIDE: Final[ErrorCode] = ErrorCode(
+MUTABLE_OVERRIDE: Final = ErrorCode(
     "mutable-override",
     "Reject covariant overrides for mutable attributes",
     "General",
@@ -274,42 +268,41 @@ def __hash__(self) -> int:
     "General",
     default_enabled=False,
 )
-METACLASS: Final[ErrorCode] = ErrorCode("metaclass", "Ensure that metaclass is valid", "General")
+METACLASS: Final = ErrorCode("metaclass", "Ensure that metaclass is valid", "General")
 
 # Syntax errors are often blocking.
-SYNTAX: Final[ErrorCode] = ErrorCode("syntax", "Report syntax errors", "General")
+SYNTAX: Final = ErrorCode("syntax", "Report syntax errors", "General")
 
 # This is an internal marker code for a whole-file ignore. It is not intended to
 # be user-visible.
 FILE: Final = ErrorCode("file", "Internal marker for a whole file being ignored", "General")
 del error_codes[FILE.code]
 
 # This is a catch-all for remaining uncategorized errors.
-MISC: Final[ErrorCode] = ErrorCode("misc", "Miscellaneous other checks", "General")
+MISC: Final = ErrorCode("misc", "Miscellaneous other checks", "General")
 
-OVERLOAD_CANNOT_MATCH: Final[ErrorCode] = ErrorCode(
+OVERLOAD_CANNOT_MATCH: Final = ErrorCode(
     "overload-cannot-match",
     "Warn if an @overload signature can never be matched",
     "General",
     sub_code_of=MISC,
 )
 
-
-OVERLOAD_OVERLAP: Final[ErrorCode] = ErrorCode(
+OVERLOAD_OVERLAP: Final = ErrorCode(
     "overload-overlap",
     "Warn if multiple @overload variants overlap in unsafe ways",
     "General",
     sub_code_of=MISC,
 )
 
-PROPERTY_DECORATOR = ErrorCode(
+PROPERTY_DECORATOR: Final = ErrorCode(
     "prop-decorator",
     "Decorators on top of @property are not supported",
     "General",
     sub_code_of=MISC,
 )
 
-NARROWED_TYPE_NOT_SUBTYPE: Final[ErrorCode] = ErrorCode(
+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",
     "General",

mypy/main.py

@@ -1270,14 +1270,16 @@ def add_invertible_flag(
 
     misc_group = parser.add_argument_group(title="Miscellaneous")
     misc_group.add_argument("--quickstart-file", help=argparse.SUPPRESS)
-    misc_group.add_argument("--junit-xml", help="Write junit.xml to the given file")
-    imports_group.add_argument(
+    misc_group.add_argument(
+        "--junit-xml",
+        metavar="JUNIT_XML_OUTPUT_FILE",
+        help="Write a JUnit XML test result document with type checking results to the given file",
+    )
+    misc_group.add_argument(
         "--junit-format",
         choices=["global", "per_file"],
         default="global",
-        help="If --junit-xml is set, specifies format."
-        + " global: single test with all errors;"
-        + " per_file: one test entry per file with failures",
+        help="If --junit-xml is set, specifies format. global (default): single test with all errors; per_file: one test entry per file with failures",
     )
     misc_group.add_argument(
         "--scripts-are-modules",

mypy/message_registry.py

@@ -11,11 +11,12 @@
 from typing import Final, NamedTuple
 
 from mypy import errorcodes as codes
+from mypy.errorcodes import ErrorCode
 
 
 class ErrorMessage(NamedTuple):
     value: str
-    code: codes.ErrorCode | None = None
+    code: ErrorCode | None = None
 
     def format(self, *args: object, **kwargs: object) -> ErrorMessage:
         return ErrorMessage(self.value.format(*args, **kwargs), code=self.code)

mypy/typeshed/stdlib/asyncio/events.pyi

@@ -602,18 +602,25 @@ class AbstractEventLoop:
     @abstractmethod
     async def shutdown_default_executor(self) -> None: ...
 
-# This class does not exist at runtime, but stubtest complains if it's marked as
-# @type_check_only because it has an alias that does exist at runtime. See mypy#19568.
-# @type_check_only
-class _AbstractEventLoopPolicy:
-    @abstractmethod
-    def get_event_loop(self) -> AbstractEventLoop: ...
-    @abstractmethod
-    def set_event_loop(self, loop: AbstractEventLoop | None) -> None: ...
-    @abstractmethod
-    def new_event_loop(self) -> AbstractEventLoop: ...
-    # Child processes handling (Unix only).
-    if sys.version_info < (3, 14):
+if sys.version_info >= (3, 14):
+    class _AbstractEventLoopPolicy:
+        @abstractmethod
+        def get_event_loop(self) -> AbstractEventLoop: ...
+        @abstractmethod
+        def set_event_loop(self, loop: AbstractEventLoop | None) -> None: ...
+        @abstractmethod
+        def new_event_loop(self) -> AbstractEventLoop: ...
+
+else:
+    @type_check_only
+    class _AbstractEventLoopPolicy:
+        @abstractmethod
+        def get_event_loop(self) -> AbstractEventLoop: ...
+        @abstractmethod
+        def set_event_loop(self, loop: AbstractEventLoop | None) -> None: ...
+        @abstractmethod
+        def new_event_loop(self) -> AbstractEventLoop: ...
+        # Child processes handling (Unix only).
         if sys.version_info >= (3, 12):
             @abstractmethod
             @deprecated("Deprecated since Python 3.12; removed in Python 3.14.")
@@ -627,7 +634,6 @@ class _AbstractEventLoopPolicy:
             @abstractmethod
             def set_child_watcher(self, watcher: AbstractChildWatcher) -> None: ...
 
-if sys.version_info < (3, 14):
     AbstractEventLoopPolicy = _AbstractEventLoopPolicy
 
 if sys.version_info >= (3, 14):