Merge branch 'master'

Author: brianschubert

docs/source/protocols.rst

@@ -352,6 +352,53 @@ the parameters are positional-only. Example (using the legacy syntax for generic
    copy_a = copy_b  # OK
    copy_b = copy_a  # Also OK
 
+Binding of types in protocol attributes
+***************************************
+
+All protocol attributes annotations are treated as externally visible types
+of those attributes. This means that for example callables are not bound,
+and descriptors are not invoked:
+
+.. code-block:: python
+
+   from typing import Callable, Protocol, overload
+
+   class Integer:
+       @overload
+       def __get__(self, instance: None, owner: object) -> Integer: ...
+       @overload
+       def __get__(self, instance: object, owner: object) -> int: ...
+       # <some implementation>
+
+   class Example(Protocol):
+       foo: Callable[[object], int]
+       bar: Integer
+
+   ex: Example
+   reveal_type(ex.foo)  # Revealed type is Callable[[object], int]
+   reveal_type(ex.bar)  # Revealed type is Integer
+
+In other words, protocol attribute types are handled as they would appear in a
+``self`` attribute annotation in a regular class. If you want some protocol
+attributes to be handled as though they were defined at class level, you should
+declare them explicitly using ``ClassVar[...]``. Continuing previous example:
+
+.. code-block:: python
+
+   from typing import ClassVar
+
+   class OtherExample(Protocol):
+       # This style is *not recommended*, but may be needed to reuse
+       # some complex callable types. Otherwise use regular methods.
+       foo: ClassVar[Callable[[object], int]]
+       # This may be needed to mimic descriptor access on Type[...] types,
+       # otherwise use a plain "bar: int" style.
+       bar: ClassVar[Integer]
+
+   ex2: OtherExample
+   reveal_type(ex2.foo)  # Revealed type is Callable[[], int]
+   reveal_type(ex2.bar)  # Revealed type is int
+
 .. _predefined_protocols_reference:
 
 Predefined protocol reference

misc/upload-pypi.py

@@ -108,7 +108,7 @@ def tmp_twine() -> Iterator[Path]:
 def upload_dist(dist: Path, dry_run: bool = True) -> None:
     with tmp_twine() as twine:
         files = [item for item in dist.iterdir() if item_ok_for_pypi(item.name)]
-        cmd: list[Any] = [twine, "upload"]
+        cmd: list[Any] = [twine, "upload", "--skip-existing"]
         cmd += files
         if dry_run:
             print("[dry run] " + " ".join(map(str, cmd)))

mypy/checkexpr.py

@@ -4288,7 +4288,9 @@ def check_boolean_op(self, e: OpExpr, context: Context) -> Type:
         ):
             self.msg.unreachable_right_operand(e.op, e.right)
 
-        right_type = self.analyze_cond_branch(right_map, e.right, expanded_left_type)
+        right_type = self.analyze_cond_branch(
+            right_map, e.right, self._combined_context(expanded_left_type)
+        )
 
         if left_map is None and right_map is None:
             return UninhabitedType()
@@ -5919,6 +5921,16 @@ def analyze_cond_branch(
             self.chk.push_type_map(map)
             return self.accept(node, type_context=context, allow_none_return=allow_none_return)
 
+    def _combined_context(self, ty: Type | None) -> Type | None:
+        ctx_items = []
+        if ty is not None:
+            ctx_items.append(ty)
+        if self.type_context and self.type_context[-1] is not None:
+            ctx_items.append(self.type_context[-1])
+        if ctx_items:
+            return make_simplified_union(ctx_items)
+        return None
+
     #
     # Helpers
     #

mypy/checkmember.py

@@ -968,7 +968,13 @@ def expand_and_bind_callable(
     # TODO: a decorated property can result in Overloaded here.
     assert isinstance(expanded, CallableType)
     if var.is_settable_property and mx.is_lvalue and var.setter_type is not None:
-        # TODO: use check_call() to infer better type, same as for __set__().
+        if expanded.variables:
+            type_ctx = mx.rvalue or TempNode(AnyType(TypeOfAny.special_form), context=mx.context)
+            _, inferred_expanded = mx.chk.expr_checker.check_call(
+                expanded, [type_ctx], [ARG_POS], mx.context
+            )
+            expanded = get_proper_type(inferred_expanded)
+            assert isinstance(expanded, CallableType)
         if not expanded.arg_types:
             # This can happen when accessing invalid property from its own body,
             # error will be reported elsewhere.
@@ -1221,6 +1227,9 @@ def analyze_class_attribute_access(
         is_classmethod = (is_decorated and cast(Decorator, node.node).func.is_class) or (
             isinstance(node.node, SYMBOL_FUNCBASE_TYPES) and node.node.is_class
         )
+        is_staticmethod = (is_decorated and cast(Decorator, node.node).func.is_static) or (
+            isinstance(node.node, SYMBOL_FUNCBASE_TYPES) and node.node.is_static
+        )
         t = get_proper_type(t)
         is_trivial_self = False
         if isinstance(node.node, Decorator):
@@ -1230,14 +1239,20 @@ def analyze_class_attribute_access(
             is_trivial_self = node.node.is_trivial_self
         if isinstance(t, FunctionLike) and is_classmethod and not is_trivial_self:
             t = check_self_arg(t, mx.self_type, False, mx.context, name, mx.msg)
-        result = add_class_tvars(
+        t = add_class_tvars(
             t,
             isuper,
             is_classmethod,
             mx,
             original_vars=original_vars,
             is_trivial_self=is_trivial_self,
         )
+        if is_decorated and not is_staticmethod:
+            t = expand_self_type_if_needed(
+                t, mx, cast(Decorator, node.node).var, itype, is_class=is_classmethod
+            )
+
+        result = t
         # __set__ is not called on class objects.
         if not mx.is_lvalue:
             result = analyze_descriptor_access(result, mx)

mypy/join.py

@@ -625,6 +625,8 @@ def visit_literal_type(self, t: LiteralType) -> ProperType:
             if self.s.fallback.type.is_enum and t.fallback.type.is_enum:
                 return mypy.typeops.make_simplified_union([self.s, t])
             return join_types(self.s.fallback, t.fallback)
+        elif isinstance(self.s, Instance) and self.s.last_known_value == t:
+            return t
         else:
             return join_types(self.s, t.fallback)
 

mypy/subtypes.py

@@ -1457,14 +1457,24 @@ def get_member_flags(name: str, itype: Instance, class_obj: bool = False) -> set
         flags = {IS_VAR}
         if not v.is_final:
             flags.add(IS_SETTABLE)
-        if v.is_classvar:
+        # TODO: define cleaner rules for class vs instance variables.
+        if v.is_classvar and not is_descriptor(v.type):
             flags.add(IS_CLASSVAR)
         if class_obj and v.is_inferred:
             flags.add(IS_CLASSVAR)
         return flags
     return set()
 
 
+def is_descriptor(typ: Type | None) -> bool:
+    typ = get_proper_type(typ)
+    if isinstance(typ, Instance):
+        return typ.type.get("__get__") is not None
+    if isinstance(typ, UnionType):
+        return all(is_descriptor(item) for item in typ.relevant_items())
+    return False
+
+
 def find_node_type(
     node: Var | FuncBase,
     itype: Instance,

test-data/unit/check-generics.test

@@ -3628,3 +3628,32 @@ def draw_none(
         takes_int_str_none(c2)
         takes_int_str_none(c3)
 [builtins fixtures/tuple.pyi]
+
+[case testPropertyWithGenericSetter]
+from typing import TypeVar
+
+class B: ...
+class C(B): ...
+T = TypeVar("T", bound=B)
+
+class Test:
+    @property
+    def foo(self) -> list[C]: ...
+    @foo.setter
+    def foo(self, val: list[T]) -> None: ...
+
+t1: Test
+t2: Test
+
+lb: list[B]
+lc: list[C]
+li: list[int]
+
+t1.foo = lb
+t1.foo = lc
+t1.foo = li  # E: Value of type variable "T" of "foo" of "Test" cannot be "int"
+
+t2.foo = [B()]
+t2.foo = [C()]
+t2.foo = [1]  # E: Value of type variable "T" of "foo" of "Test" cannot be "int"
+[builtins fixtures/property.pyi]

test-data/unit/check-inference-context.test

@@ -1510,3 +1510,24 @@ def mymin(
 def check(paths: Iterable[str], key: Callable[[str], int]) -> Union[str, None]:
     return mymin(paths, key=key, default=None)
 [builtins fixtures/tuple.pyi]
+
+[case testBinaryOpInferenceContext]
+from typing import Literal, TypeVar
+
+T = TypeVar("T")
+
+def identity(x: T) -> T:
+    return x
+
+def check1(use: bool, val: str) -> "str | Literal[True]":
+    return use or identity(val)
+
+def check2(use: bool, val: str) -> "str | bool":
+    return use or identity(val)
+
+def check3(use: bool, val: str) -> "str | Literal[False]":
+    return use and identity(val)
+
+def check4(use: bool, val: str) -> "str | bool":
+    return use and identity(val)
+[builtins fixtures/tuple.pyi]

test-data/unit/check-literal.test

@@ -2976,3 +2976,22 @@ x: Type[Literal[1]]  # E: Type[...] can't contain "Literal[...]"
 y: Type[Union[Literal[1], Literal[2]]]  # E: Type[...] can't contain "Union[Literal[...], Literal[...]]"
 z: Type[Literal[1, 2]]  # E: Type[...] can't contain "Union[Literal[...], Literal[...]]"
 [builtins fixtures/tuple.pyi]
+
+[case testJoinLiteralAndInstance]
+from typing import Generic, TypeVar, Literal
+
+T = TypeVar("T")
+
+class A(Generic[T]): ...
+
+def f(a: A[T], t: T) -> T: ...
+def g(a: T, t: A[T]) -> T: ...
+
+def check(obj: A[Literal[1]]) -> None:
+    reveal_type(f(obj, 1))  # N: Revealed type is "Literal[1]"
+    reveal_type(f(obj, ''))  # E: Cannot infer type argument 1 of "f" \
+                             # N: Revealed type is "Any"
+    reveal_type(g(1, obj))  # N: Revealed type is "Literal[1]"
+    reveal_type(g('', obj))  # E: Cannot infer type argument 1 of "g" \
+                             # N: Revealed type is "Any"
+[builtins fixtures/tuple.pyi]

test-data/unit/check-protocols.test

@@ -4602,3 +4602,47 @@ def deco(fn: Callable[[], T]) -> Callable[[], list[T]]: ...
 @deco
 def defer() -> int: ...
 [builtins fixtures/list.pyi]
+
+[case testProtocolClassValDescriptor]
+from typing import Any, Protocol, overload, ClassVar, Type
+
+class Desc:
+    @overload
+    def __get__(self, instance: None, owner: object) -> Desc: ...
+    @overload
+    def __get__(self, instance: object, owner: object) -> int: ...
+    def __get__(self, instance, owner):
+        pass
+
+class P(Protocol):
+    x: ClassVar[Desc]
+
+class C:
+    x = Desc()
+
+t: P = C()
+reveal_type(t.x)  # N: Revealed type is "builtins.int"
+tt: Type[P] = C
+reveal_type(tt.x)  # N: Revealed type is "__main__.Desc"
+
+bad: P = C  # E: Incompatible types in assignment (expression has type "type[C]", variable has type "P") \
+            # N: Following member(s) of "C" have conflicts: \
+            # N:     x: expected "int", got "Desc"
+
+[case testProtocolClassValCallable]
+from typing import Any, Protocol, overload, ClassVar, Type, Callable
+
+class P(Protocol):
+    foo: Callable[[object], int]
+    bar: ClassVar[Callable[[object], int]]
+
+class C:
+    foo: Callable[[object], int]
+    bar: ClassVar[Callable[[object], int]]
+
+t: P = C()
+reveal_type(t.foo)  # N: Revealed type is "def (builtins.object) -> builtins.int"
+reveal_type(t.bar)  # N: Revealed type is "def () -> builtins.int"
+tt: Type[P] = C
+reveal_type(tt.foo)  # N: Revealed type is "def (builtins.object) -> builtins.int"
+reveal_type(tt.bar)  # N: Revealed type is "def (builtins.object) -> builtins.int"