Merge branch 'master' of https://github.com/python/mypy into dataclas…

…s-transform-field-specifiers
python · JukkaL · Feb 15, 2023 · Feb 9, 2023 · Feb 13, 2023 · Feb 13, 2023
commit 1aaa3177b07393eed3270da50d5a9c36eb5778d4
diff --git a/mypy/plugins/dataclasses.py b/mypy/plugins/dataclasses.py
@@ -520,11 +520,11 @@ def collect_attributes(self) -> list[DataclassAttribute] | None:
             # kw_only value from the decorator parameter.
             field_kw_only_param = field_args.get("kw_only")
             if field_kw_only_param is not None:
-                value = ctx.api.parse_bool(field_kw_only_param)
+                value = self._api.parse_bool(field_kw_only_param)
                 if value is not None:
                     is_kw_only = value
                 else:
-                    ctx.api.fail('"kw_only" argument must be True or False.', stmt.rvalue)
+                    self._api.fail('"kw_only" argument must be True or False.', stmt.rvalue)
 
             if sym.type is None and node.is_final and node.is_inferred:
                 # This is a special case, assignment like x: Final = 42 is classified
@@ -544,9 +544,9 @@ def collect_attributes(self) -> list[DataclassAttribute] | None:
 
             alias = None
             if "alias" in field_args:
-                alias = self._ctx.api.parse_str_literal(field_args["alias"])
+                alias = self._api.parse_str_literal(field_args["alias"])
                 if alias is None:
-                    self._ctx.api.fail(
+                    self._api.fail(
                         message_registry.DATACLASS_FIELD_ALIAS_MUST_BE_LITERAL,
                         stmt.rvalue,
                         code=errorcodes.LITERAL_REQ,

diff --git a/test-data/unit/check-dataclass-transform.test b/test-data/unit/check-dataclass-transform.test
@@ -276,3 +276,127 @@ Foo.__dataclass_fields__  # E: "Type[Foo]" has no attribute "__dataclass_fields_
 
 [typing fixtures/typing-full.pyi]
 [builtins fixtures/dataclasses.pyi]
+
+[case testDataclassTransformOverloadsDecoratorOnOverload]
+# flags: --python-version 3.11
+from typing import dataclass_transform, overload, Any, Callable, Type, Literal
+
+@overload
+def my_dataclass(*, foo: str) -> Callable[[Type], Type]: ...
+@overload
+@dataclass_transform(frozen_default=True)
+def my_dataclass(*, foo: int) -> Callable[[Type], Type]: ...
+def my_dataclass(*, foo: Any) -> Callable[[Type], Type]:
+    return lambda cls: cls
+@my_dataclass(foo="hello")
+class A:
+    a: int
+@my_dataclass(foo=5)
+class B:
+    b: int
+
+reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> __main__.A"
+reveal_type(B)  # N: Revealed type is "def (b: builtins.int) -> __main__.B"
+A(1, "hello")  # E: Too many arguments for "A"
+a = A(1)
+a.a = 2  # E: Property "a" defined in "A" is read-only
+
+[typing fixtures/typing-full.pyi]
+[builtins fixtures/dataclasses.pyi]
+
+[case testDataclassTransformOverloadsDecoratorOnImpl]
+# flags: --python-version 3.11
+from typing import dataclass_transform, overload, Any, Callable, Type, Literal
+
+@overload
+def my_dataclass(*, foo: str) -> Callable[[Type], Type]: ...
+@overload
+def my_dataclass(*, foo: int) -> Callable[[Type], Type]: ...
+@dataclass_transform(frozen_default=True)
+def my_dataclass(*, foo: Any) -> Callable[[Type], Type]:
+    return lambda cls: cls
+@my_dataclass(foo="hello")
+class A:
+    a: int
+@my_dataclass(foo=5)
+class B:
+    b: int
+
+reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> __main__.A"
+reveal_type(B)  # N: Revealed type is "def (b: builtins.int) -> __main__.B"
+A(1, "hello")  # E: Too many arguments for "A"
+a = A(1)
+a.a = 2  # E: Property "a" defined in "A" is read-only
+
+[typing fixtures/typing-full.pyi]
+[builtins fixtures/dataclasses.pyi]
+
+[case testDataclassTransformViaBaseClass]
+# flags: --python-version 3.11
+from typing import dataclass_transform
+
+@dataclass_transform(frozen_default=True)
+class Dataclass:
+    def __init_subclass__(cls, *, kw_only: bool = False): ...
+
+class Person(Dataclass, kw_only=True):
+    name: str
+    age: int
+
+reveal_type(Person)  # N: Revealed type is "def (*, name: builtins.str, age: builtins.int) -> __main__.Person"
+Person('Jonh', 21)  # E: Too many positional arguments for "Person"
+person = Person(name='John', age=32)
+person.name = "John Smith"  # E: Property "name" defined in "Person" is read-only
+
+class Contact(Person):
+    email: str
+
+reveal_type(Contact)  # N: Revealed type is "def (email: builtins.str, *, name: builtins.str, age: builtins.int) -> __main__.Contact"
+Contact('john@john.com', name='John', age=32)
+
+[typing fixtures/typing-full.pyi]
+[builtins fixtures/dataclasses.pyi]
+
+[case testDataclassTransformViaMetaclass]
+# flags: --python-version 3.11
+from typing import dataclass_transform
+
+@dataclass_transform(frozen_default=True)
+class Dataclass(type): ...
+
+class Person(metaclass=Dataclass, kw_only=True):
+    name: str
+    age: int
+
+reveal_type(Person)  # N: Revealed type is "def (*, name: builtins.str, age: builtins.int) -> __main__.Person"
+Person('Jonh', 21)  # E: Too many positional arguments for "Person"
+person = Person(name='John', age=32)
+person.name = "John Smith"  # E: Property "name" defined in "Person" is read-only
+
+class Contact(Person):
+    email: str
+
+reveal_type(Contact)  # N: Revealed type is "def (email: builtins.str, *, name: builtins.str, age: builtins.int) -> __main__.Contact"
+Contact('john@john.com', name='John', age=32)
+
+[typing fixtures/typing-full.pyi]
+[builtins fixtures/dataclasses.pyi]
+
+[case testDataclassTransformViaSubclassOfMetaclass]
+# flags: --python-version 3.11
+from typing import dataclass_transform
+
+@dataclass_transform(frozen_default=True)
+class BaseMeta(type): ...
+class SubMeta(BaseMeta): ...
+
+# MyPy does *not* recognize this as a dataclass because the metaclass is not directly decorated with
+# dataclass_transform
+class Foo(metaclass=SubMeta):
+    foo: int
+
+reveal_type(Foo)  # N: Revealed type is "def () -> __main__.Foo"
+Foo(1)  # E: Too many arguments for "Foo"
+
+[typing fixtures/typing-full.pyi]
+[builtins fixtures/dataclasses.pyi]