Merge branch 'master' into strict-arg

Author: hauntsaninja

.github/workflows/mypy_primer.yml

@@ -74,9 +74,9 @@ jobs:
         name: Save PR number
         run: |
           echo ${{ github.event.pull_request.number }} | tee pr_number.txt
-      - if: ${{ matrix.shard-index == 0 }}
-        name: Upload mypy_primer diff + PR number
+      - name: Upload mypy_primer diff + PR number
         uses: actions/upload-artifact@v4
+        if: ${{ matrix.shard-index == 0 }}
         with:
           name: mypy_primer_diffs-${{ matrix.shard-index }}
           path: |

.github/workflows/mypy_primer_comment.yml

@@ -48,7 +48,7 @@ jobs:
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
-            const MAX_CHARACTERS = 30000
+            const MAX_CHARACTERS = 50000
             const MAX_CHARACTERS_PER_PROJECT = MAX_CHARACTERS / 3
 
             const fs = require('fs')

CHANGELOG.md

@@ -2,7 +2,25 @@
 
 ## Next release
 
-...
+### `--strict-bytes`
+
+By default, mypy treats an annotation of ``bytes`` as permitting ``bytearray`` and ``memoryview``.
+[PEP 688](https://peps.python.org/pep-0688) specified the removal of this special case.
+Use this flag to disable this behavior. `--strict-bytes` will be enabled by default in **mypy 2.0**.
+
+Contributed by Ali Hamdan (PR [18137](https://github.com/python/mypy/pull/18263/)) and
+Shantanu Jain (PR [13952](https://github.com/python/mypy/pull/13952)).
+
+### Improvements to partial type handling in loops
+
+This change results in mypy better modelling control flow within loops and hence detecting several
+issues it previously did not detect. In some cases, this change may require use of an additional
+explicit annotation of a variable.
+
+Contributed by Christoph Tyralla (PR [18180](https://github.com/python/mypy/pull/18180)).
+
+(Speaking of partial types, another reminder that mypy plans on enabling `--local-partial-types`
+by default in **mypy 2.0**).
 
 ## Mypy 1.14
 

mypy/main.py

@@ -10,7 +10,7 @@
 from collections import defaultdict
 from gettext import gettext
 from io import TextIOWrapper
-from typing import IO, Any, Final, NoReturn, Sequence, TextIO
+from typing import IO, Any, Final, NoReturn, Protocol, Sequence, TextIO
 
 from mypy import build, defaults, state, util
 from mypy.config_parser import (
@@ -35,6 +35,11 @@
 from mypy.split_namespace import SplitNamespace
 from mypy.version import __version__
 
+
+class _SupportsWrite(Protocol):
+    def write(self, s: str, /) -> object: ...
+
+
 orig_stat: Final = os.stat
 MEM_PROFILE: Final = False  # If True, dump memory profile
 
@@ -372,17 +377,17 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
     # =====================
     # Help-printing methods
     # =====================
-    def print_usage(self, file: IO[str] | None = None) -> None:
+    def print_usage(self, file: _SupportsWrite | None = None) -> None:
         if file is None:
             file = self.stdout
         self._print_message(self.format_usage(), file)
 
-    def print_help(self, file: IO[str] | None = None) -> None:
+    def print_help(self, file: _SupportsWrite | None = None) -> None:
         if file is None:
             file = self.stdout
         self._print_message(self.format_help(), file)
 
-    def _print_message(self, message: str, file: IO[str] | None = None) -> None:
+    def _print_message(self, message: str, file: _SupportsWrite | None = None) -> None:
         if message:
             if file is None:
                 file = self.stderr

mypy/messages.py

@@ -2700,7 +2700,7 @@ def format_literal_value(typ: LiteralType) -> str:
         if func.is_type_obj():
             # The type of a type object type can be derived from the
             # return type (this always works).
-            return format(TypeType.make_normalized(erase_type(func.items[0].ret_type)))
+            return format(TypeType.make_normalized(func.items[0].ret_type))
         elif isinstance(func, CallableType):
             if func.type_guard is not None:
                 return_type = f"TypeGuard[{format(func.type_guard)}]"

mypy/mixedtraverser.py

@@ -30,14 +30,14 @@ def __init__(self) -> None:
 
     # Symbol nodes
 
-    def visit_var(self, var: Var) -> None:
+    def visit_var(self, var: Var, /) -> None:
         self.visit_optional_type(var.type)
 
-    def visit_func(self, o: FuncItem) -> None:
+    def visit_func(self, o: FuncItem, /) -> None:
         super().visit_func(o)
         self.visit_optional_type(o.type)
 
-    def visit_class_def(self, o: ClassDef) -> None:
+    def visit_class_def(self, o: ClassDef, /) -> None:
         # TODO: Should we visit generated methods/variables as well, either here or in
         #       TraverserVisitor?
         super().visit_class_def(o)
@@ -46,67 +46,67 @@ def visit_class_def(self, o: ClassDef) -> None:
             for base in info.bases:
                 base.accept(self)
 
-    def visit_type_alias_expr(self, o: TypeAliasExpr) -> None:
+    def visit_type_alias_expr(self, o: TypeAliasExpr, /) -> None:
         super().visit_type_alias_expr(o)
         self.in_type_alias_expr = True
         o.node.target.accept(self)
         self.in_type_alias_expr = False
 
-    def visit_type_var_expr(self, o: TypeVarExpr) -> None:
+    def visit_type_var_expr(self, o: TypeVarExpr, /) -> None:
         super().visit_type_var_expr(o)
         o.upper_bound.accept(self)
         for value in o.values:
             value.accept(self)
 
-    def visit_typeddict_expr(self, o: TypedDictExpr) -> None:
+    def visit_typeddict_expr(self, o: TypedDictExpr, /) -> None:
         super().visit_typeddict_expr(o)
         self.visit_optional_type(o.info.typeddict_type)
 
-    def visit_namedtuple_expr(self, o: NamedTupleExpr) -> None:
+    def visit_namedtuple_expr(self, o: NamedTupleExpr, /) -> None:
         super().visit_namedtuple_expr(o)
         assert o.info.tuple_type
         o.info.tuple_type.accept(self)
 
-    def visit__promote_expr(self, o: PromoteExpr) -> None:
+    def visit__promote_expr(self, o: PromoteExpr, /) -> None:
         super().visit__promote_expr(o)
         o.type.accept(self)
 
-    def visit_newtype_expr(self, o: NewTypeExpr) -> None:
+    def visit_newtype_expr(self, o: NewTypeExpr, /) -> None:
         super().visit_newtype_expr(o)
         self.visit_optional_type(o.old_type)
 
     # Statements
 
-    def visit_assignment_stmt(self, o: AssignmentStmt) -> None:
+    def visit_assignment_stmt(self, o: AssignmentStmt, /) -> None:
         super().visit_assignment_stmt(o)
         self.visit_optional_type(o.type)
 
-    def visit_for_stmt(self, o: ForStmt) -> None:
+    def visit_for_stmt(self, o: ForStmt, /) -> None:
         super().visit_for_stmt(o)
         self.visit_optional_type(o.index_type)
 
-    def visit_with_stmt(self, o: WithStmt) -> None:
+    def visit_with_stmt(self, o: WithStmt, /) -> None:
         super().visit_with_stmt(o)
         for typ in o.analyzed_types:
             typ.accept(self)
 
     # Expressions
 
-    def visit_cast_expr(self, o: CastExpr) -> None:
+    def visit_cast_expr(self, o: CastExpr, /) -> None:
         super().visit_cast_expr(o)
         o.type.accept(self)
 
-    def visit_assert_type_expr(self, o: AssertTypeExpr) -> None:
+    def visit_assert_type_expr(self, o: AssertTypeExpr, /) -> None:
         super().visit_assert_type_expr(o)
         o.type.accept(self)
 
-    def visit_type_application(self, o: TypeApplication) -> None:
+    def visit_type_application(self, o: TypeApplication, /) -> None:
         super().visit_type_application(o)
         for t in o.types:
             t.accept(self)
 
     # Helpers
 
-    def visit_optional_type(self, t: Type | None) -> None:
+    def visit_optional_type(self, t: Type | None, /) -> None:
         if t:
             t.accept(self)

mypy/stubtest.py

@@ -670,7 +670,7 @@ def _verify_arg_default_value(
     stub_arg: nodes.Argument, runtime_arg: inspect.Parameter
 ) -> Iterator[str]:
     """Checks whether argument default values are compatible."""
-    if runtime_arg.default != inspect.Parameter.empty:
+    if runtime_arg.default is not inspect.Parameter.empty:
         if stub_arg.kind.is_required():
             yield (
                 f'runtime argument "{runtime_arg.name}" '
@@ -705,18 +705,26 @@ def _verify_arg_default_value(
                     stub_default is not UNKNOWN
                     and stub_default is not ...
                     and runtime_arg.default is not UNREPRESENTABLE
-                    and (
-                        stub_default != runtime_arg.default
-                        # We want the types to match exactly, e.g. in case the stub has
-                        # True and the runtime has 1 (or vice versa).
-                        or type(stub_default) is not type(runtime_arg.default)
-                    )
                 ):
-                    yield (
-                        f'runtime argument "{runtime_arg.name}" '
-                        f"has a default value of {runtime_arg.default!r}, "
-                        f"which is different from stub argument default {stub_default!r}"
-                    )
+                    defaults_match = True
+                    # We want the types to match exactly, e.g. in case the stub has
+                    # True and the runtime has 1 (or vice versa).
+                    if type(stub_default) is not type(runtime_arg.default):
+                        defaults_match = False
+                    else:
+                        try:
+                            defaults_match = bool(stub_default == runtime_arg.default)
+                        except Exception:
+                            # Exception can be raised in bool dunder method (e.g. numpy arrays)
+                            # At this point, consider the default to be different, it is probably
+                            # too complex to put in a stub anyway.
+                            defaults_match = False
+                    if not defaults_match:
+                        yield (
+                            f'runtime argument "{runtime_arg.name}" '
+                            f"has a default value of {runtime_arg.default!r}, "
+                            f"which is different from stub argument default {stub_default!r}"
+                        )
     else:
         if stub_arg.kind.is_optional():
             yield (
@@ -758,7 +766,7 @@ def get_type(arg: Any) -> str | None:
 
         def has_default(arg: Any) -> bool:
             if isinstance(arg, inspect.Parameter):
-                return bool(arg.default != inspect.Parameter.empty)
+                return arg.default is not inspect.Parameter.empty
             if isinstance(arg, nodes.Argument):
                 return arg.kind.is_optional()
             raise AssertionError
@@ -1628,13 +1636,13 @@ def anytype() -> mypy.types.AnyType:
                 arg_names.append(
                     None if arg.kind == inspect.Parameter.POSITIONAL_ONLY else arg.name
                 )
-                has_default = arg.default == inspect.Parameter.empty
+                no_default = arg.default is inspect.Parameter.empty
                 if arg.kind == inspect.Parameter.POSITIONAL_ONLY:
-                    arg_kinds.append(nodes.ARG_POS if has_default else nodes.ARG_OPT)
+                    arg_kinds.append(nodes.ARG_POS if no_default else nodes.ARG_OPT)
                 elif arg.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
-                    arg_kinds.append(nodes.ARG_POS if has_default else nodes.ARG_OPT)
+                    arg_kinds.append(nodes.ARG_POS if no_default else nodes.ARG_OPT)
                 elif arg.kind == inspect.Parameter.KEYWORD_ONLY:
-                    arg_kinds.append(nodes.ARG_NAMED if has_default else nodes.ARG_NAMED_OPT)
+                    arg_kinds.append(nodes.ARG_NAMED if no_default else nodes.ARG_NAMED_OPT)
                 elif arg.kind == inspect.Parameter.VAR_POSITIONAL:
                     arg_kinds.append(nodes.ARG_STAR)
                 elif arg.kind == inspect.Parameter.VAR_KEYWORD:

mypy/test/test_find_sources.py

@@ -17,20 +17,20 @@ class FakeFSCache(FileSystemCache):
     def __init__(self, files: set[str]) -> None:
         self.files = {os.path.abspath(f) for f in files}
 
-    def isfile(self, file: str) -> bool:
-        return file in self.files
+    def isfile(self, path: str) -> bool:
+        return path in self.files
 
-    def isdir(self, dir: str) -> bool:
-        if not dir.endswith(os.sep):
-            dir += os.sep
-        return any(f.startswith(dir) for f in self.files)
+    def isdir(self, path: str) -> bool:
+        if not path.endswith(os.sep):
+            path += os.sep
+        return any(f.startswith(path) for f in self.files)
 
-    def listdir(self, dir: str) -> list[str]:
-        if not dir.endswith(os.sep):
-            dir += os.sep
-        return list({f[len(dir) :].split(os.sep)[0] for f in self.files if f.startswith(dir)})
+    def listdir(self, path: str) -> list[str]:
+        if not path.endswith(os.sep):
+            path += os.sep
+        return list({f[len(path) :].split(os.sep)[0] for f in self.files if f.startswith(path)})
 
-    def init_under_package_root(self, file: str) -> bool:
+    def init_under_package_root(self, path: str) -> bool:
         return False
 
 

mypy/test/testpep561.py

@@ -23,8 +23,8 @@ class PEP561Suite(DataSuite):
     files = ["pep561.test"]
     base_path = "."
 
-    def run_case(self, test_case: DataDrivenTestCase) -> None:
-        test_pep561(test_case)
+    def run_case(self, testcase: DataDrivenTestCase) -> None:
+        test_pep561(testcase)
 
 
 @contextmanager

mypy/test/teststubtest.py

@@ -529,6 +529,18 @@ def f11(text=None) -> None: pass
             error="f11",
         )
 
+        # Simulate numpy ndarray.__bool__ that raises an error
+        yield Case(
+            stub="def f12(x=1): ...",
+            runtime="""
+            class _ndarray:
+                def __eq__(self, obj): return self
+                def __bool__(self): raise ValueError
+            def f12(x=_ndarray()) -> None: pass
+            """,
+            error="f12",
+        )
+
     @collect_cases
     def test_static_class_method(self) -> Iterator[Case]:
         yield Case(