test-data/unit/check-classes.test

-- Methods
-- -------


[case testMethodCall]

a = None # type: A
b = None # type: B

a.foo(B())        # Fail
a.bar(B(), A())   # Fail

a.foo(A())
b.bar(B(), A())

class A:
    def foo(self, x: 'A') -> None: pass
class B:
    def bar(self, x: 'B', y: A) -> None: pass
[out]
main:5: error: Argument 1 to "foo" of "A" has incompatible type "B"; expected "A"
main:6: error: "A" has no attribute "bar"

[case testMethodCallWithSubtype]

a = None # type: A
a.foo(A())
a.foo(B())
a.bar(A()) # Fail
a.bar(B())

class A:
    def foo(self, x: 'A') -> None: pass
    def bar(self, x: 'B') -> None: pass
class B(A): pass
[out]
main:5: error: Argument 1 to "bar" of "A" has incompatible type "A"; expected "B"

[case testInheritingMethod]

a = None # type: B
a.foo(A()) # Fail
a.foo(B())

class A:
    def foo(self, x: 'B') -> None: pass
class B(A): pass
[out]
main:3: error: Argument 1 to "foo" of "A" has incompatible type "A"; expected "B"

[case testMethodCallWithInvalidNumberOfArguments]

a = None # type: A
a.foo()               # Fail
a.foo(object(), A())  # Fail

class A:
    def foo(self, x: 'A') -> None: pass
[out]
main:3: error: Too few arguments for "foo" of "A"
main:4: error: Too many arguments for "foo" of "A"
main:4: error: Argument 1 to "foo" of "A" has incompatible type "object"; expected "A"

[case testMethodBody]
import typing
class A:
    def f(self) -> None:
        a = object() # type: A    # Fail
[out]
main:4: error: Incompatible types in assignment (expression has type "object", variable has type "A")

[case testMethodArguments]
import typing
class A:
    def f(self, a: 'A', b: 'B') -> None:
        a = B() # Fail
        b = A() # Fail
        a = A()
        b = B()
        a = a
        a = b # Fail
class B: pass
[out]
main:4: error: Incompatible types in assignment (expression has type "B", variable has type "A")
main:5: error: Incompatible types in assignment (expression has type "A", variable has type "B")
main:9: error: Incompatible types in assignment (expression has type "B", variable has type "A")

[case testReturnFromMethod]
import typing
class A:
    def f(self) -> 'A':
        return B() # Fail
        return A()
class B: pass
[out]
main:4: error: Incompatible return value type (got "B", expected "A")

[case testSelfArgument]
import typing
class A:
    def f(self) -> None:
        o = self # type: B    # Fail
        self.g()      # Fail
        a = self # type: A
        self.f()
class B: pass
[out]
main:4: error: Incompatible types in assignment (expression has type "A", variable has type "B")
main:5: error: "A" has no attribute "g"

[case testAssignToMethodViaInstance]
import typing
class A:
    def f(self): pass
A().f = None # E: Cannot assign to a method


-- Attributes
-- ----------


[case testReferToInvalidAttribute]

class A:
    def __init__(self):
        self.x = object()
a = None # type: A
a.y
a.y = object()
a.x
a.x = object()
[out]
main:6: error: "A" has no attribute "y"
main:7: error: "A" has no attribute "y"

[case testArgumentTypeInference]

class A:
    def __init__(self, aa: 'A', bb: 'B') -> None:
        self.a = aa
        self.b = bb
class B: pass
a = None # type: A
b = None # type: B
a.a = b # Fail
a.b = a # Fail
b.a     # Fail
a.a = a
a.b = b
[out]
main:9: error: Incompatible types in assignment (expression has type "B", variable has type "A")
main:10: error: Incompatible types in assignment (expression has type "A", variable has type "B")
main:11: error: "B" has no attribute "a"

[case testExplicitAttributeInBody]

a = None # type: A
a.x = object() # Fail
a.x = A()
class A:
  x = None # type: A
[out]
main:3: error: Incompatible types in assignment (expression has type "object", variable has type "A")

[case testAttributeDefinedInNonInitMethod]
import typing
class A:
    def f(self) -> None:
        self.x = 1
        self.y = ''
        self.x = 1
a = A()
a.x = 1
a.y = ''
a.x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")
a.z = 0  # E: "A" has no attribute "z"

[case testInheritanceAndAttributeAssignment]
import typing
class A:
    def f(self) -> None:
        self.x = 0
class B(A):
    def f(self) -> None:
        self.x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")
[out]

[case testAssignmentToAttributeInMultipleMethods]
import typing
class A:
    def f(self) -> None:
        self.x = 0
    def g(self) -> None:
        self.x = '' # Fail
    def __init__(self) -> None:
        self.x = '' # Fail
[out]
main:6: error: Incompatible types in assignment (expression has type "str", variable has type "int")
main:8: error: Incompatible types in assignment (expression has type "str", variable has type "int")


-- Method overriding
-- -----------------


[case testMethodOverridingWithIdenticalSignature]
import typing
class A:
    def f(self, x: 'A') -> None: pass
    def g(self, x: 'B' , y: object) -> 'A': pass
    def h(self) -> None: pass
class B(A):
    def f(self, x: A) -> None: pass
    def g(self, x: 'B' , y: object) -> A: pass
    def h(self) -> None: pass
[out]

[case testMethodOverridingWithCovariantType]
import typing
class A:
  def f(self, x: 'A', y: 'B') -> 'A': pass
  def g(self, x: 'A', y: 'B') -> 'A': pass
class B(A):
  def f(self, x: A, y: 'B') -> 'B': pass
  def g(self, x: A, y: A) -> 'A': pass
[out]

[case testMethodOverridingWithIncompatibleTypes]
import typing
class A:
  def f(self, x: 'A', y: 'B') -> 'A': pass
  def g(self, x: 'A', y: 'B') -> 'A': pass
  def h(self, x: 'A', y: 'B') -> 'A': pass
class B(A):
  def f(self, x: 'B', y: 'B') -> A: pass  # Fail
  def g(self, x: A, y: A) -> A: pass
  def h(self, x: A, y: 'B') -> object: pass  # Fail
[out]
main:7: error: Argument 1 of "f" incompatible with supertype "A"
main:9: error: Return type of "h" incompatible with supertype "A"

[case testMethodOverridingWithIncompatibleArgumentCount]
import typing
class A:
    def f(self, x: 'A') -> None: pass
    def g(self, x: 'A', y: 'B') -> 'A': pass
class B(A):
    def f(self, x: A, y: A) -> None: pass # Fail
    def g(self, x: A) -> A: pass # Fail
[out]
main:6: error: Signature of "f" incompatible with supertype "A"
main:7: error: Signature of "g" incompatible with supertype "A"

[case testMethodOverridingAcrossDeepInheritanceHierarchy1]
import typing
class A:
    def f(self, x: 'B') -> None: pass
class B(A): pass
class C(B): # with gap in implementations
    def f(self, x: 'C') -> None:  # Fail
        pass
[out]
main:6: error: Argument 1 of "f" incompatible with supertype "A"

[case testMethodOverridingAcrossDeepInheritanceHierarchy2]
import typing
class A:
    def f(self) -> 'B': pass
class B(A):
    def f(self) -> 'C': pass
class C(B): # with multiple implementations
    def f(self) -> B:  # Fail
        pass
[out]
main:7: error: Return type of "f" incompatible with supertype "B"

[case testMethodOverridingWithVoidReturnValue]
import typing
class A:
    def f(self) -> None: pass
    def g(self) -> 'A': pass
class B(A):
    def f(self) -> A: pass  # Fail
    def g(self) -> None: pass  # Fail
[out]
main:6: error: Return type of "f" incompatible with supertype "A"
main:7: error: Return type of "g" incompatible with supertype "A"

[case testOverride__new__WithDifferentSignature]
class A:
    def __new__(cls, x: int) -> str:
        return ''

class B(A):
    def __new__(cls) -> int:
        return 1

[case testInnerFunctionNotOverriding]
class A:
    def f(self) -> int: pass

class B(A):
    def g(self) -> None:
        def f(self) -> str: pass


-- Constructors
-- ------------


[case testTrivialConstructor]
import typing
a = A() # type: A
b = A() # type: B # Fail
class A:
    def __init__(self) -> None: pass
class B: pass
[out]
main:3: error: Incompatible types in assignment (expression has type "A", variable has type "B")

[case testConstructor]
import typing
a = A(B()) # type: A
aa = A(object()) # type: A  # Fail
b = A(B()) # type: B       # Fail
class A:
    def __init__(self, x: 'B') -> None: pass
class B: pass
[out]
main:3: error: Argument 1 to "A" has incompatible type "object"; expected "B"
main:4: error: Incompatible types in assignment (expression has type "A", variable has type "B")

[case testConstructorWithTwoArguments]
import typing
a = A(C(), B()) # type: A  # Fail

class A:
    def __init__(self, x: 'B', y: 'C') -> None: pass
class B: pass
class C(B): pass
[out]
main:2: error: Argument 2 to "A" has incompatible type "B"; expected "C"

[case testInheritedConstructor]
import typing
b = B(C()) # type: B
a = B(D()) # type: A # Fail
class A:
    def __init__(self, x: 'C') -> None: pass
class B(A): pass
class C: pass
class D: pass
[out]
main:3: error: Argument 1 to "B" has incompatible type "D"; expected "C"

[case testOverridingWithIncompatibleConstructor]
import typing
A()    # Fail
B(C()) # Fail
A(C())
B()
class A:
    def __init__(self, x: 'C') -> None: pass
class B(A):
    def __init__(self) -> None: pass
class C: pass
[out]
main:2: error: Too few arguments for "A"
main:3: error: Too many arguments for "B"

[case testConstructorWithReturnValueType]
import typing
class A:
    def __init__(self) -> 'A': pass
[out]
main:3: error: The return type of "__init__" must be None

[case testConstructorWithImplicitReturnValueType]
import typing
class A:
    def __init__(self, x: int): pass
[out]
main:3: error: The return type of "__init__" must be None

[case testInitSubclassWithReturnValueType]
import typing
class A:
    def __init_subclass__(cls) -> 'A': pass
[out]
main:3: error: The return type of "__init_subclass__" must be None

[case testInitSubclassWithImplicitReturnValueType]
import typing
class A:
    def __init_subclass__(cls, x: int=1): pass
[out]
main:3: error: The return type of "__init_subclass__" must be None

[case testGlobalFunctionInitWithReturnType]
import typing
a = __init__() # type: A
b = __init__() # type: B # Fail
def __init__() -> 'A': pass
class A: pass
class B: pass
[out]
main:3: error: Incompatible types in assignment (expression has type "A", variable has type "B")

[case testAccessingInit]
from typing import Any
class A:
    def __init__(self, a: 'A') -> None: pass
a = None # type: A
a.__init__(a)  # E: Cannot access "__init__" directly
(Any(a)).__init__(a)

[case testDeepInheritanceHierarchy]
import typing
d = C() # type: D  # Fail
d = B()      # Fail
d = A()      # Fail
d = D2()     # Fail
a = D() # type: A
a = D2()
b = D() # type: B
b = D2()

class A: pass
class B(A): pass
class C(B): pass
class D(C): pass
class D2(C): pass
[out]
main:2: error: Incompatible types in assignment (expression has type "C", variable has type "D")
main:3: error: Incompatible types in assignment (expression has type "B", variable has type "D")
main:4: error: Incompatible types in assignment (expression has type "A", variable has type "D")
main:5: error: Incompatible types in assignment (expression has type "D2", variable has type "D")


-- Attribute access in class body
-- ------------------------------


[case testDataAttributeRefInClassBody]
import typing
class B: pass
class A:
    x = B()
    y = x
    b = x # type: B
    b = x
    c = x # type: A # E: Incompatible types in assignment (expression has type "B", variable has type "A")
    c = b   # E: Incompatible types in assignment (expression has type "B", variable has type "A")
[out]

[case testMethodRefInClassBody]
from typing import Callable
class B: pass
class A:
    def f(self) -> None: pass
    g = f
    h = f # type: Callable[[A], None]
    h = f
    g = h
    ff = f # type: Callable[[B], None]  # E: Incompatible types in assignment (expression has type Callable[[A], None], variable has type Callable[[B], None])
    g = ff                # E: Incompatible types in assignment (expression has type Callable[[B], None], variable has type Callable[[A], None])
[out]


-- Arbitrary statements in class body
-- ----------------------------------


[case testStatementsInClassBody]
import typing
class B: pass
class A:
    for x in [A()]:
        y = x
        y = B() # E: Incompatible types in assignment (expression has type "B", variable has type "A")
    x = A()
    y = A()
    x = B() # E: Incompatible types in assignment (expression has type "B", variable has type "A")
[builtins fixtures/for.pyi]
[out]


-- Class attributes
-- ----------------


[case testAccessMethodViaClass]
import typing
class A:
    def f(self) -> None: pass
A.f(A())
A.f(object())     # E: Argument 1 to "f" of "A" has incompatible type "object"; expected "A"
A.f()             # E: Too few arguments for "f" of "A"
A.f(None, None)   # E: Too many arguments for "f" of "A"

[case testAccessAttributeViaClass]
import typing
class B: pass
class A:
    x = None # type: A
a = A.x # type: A
b = A.x # type: B # E: Incompatible types in assignment (expression has type "A", variable has type "B")

[case testAccessingUndefinedAttributeViaClass]
import typing
class A: pass
A.x # E: "A" has no attribute "x"

[case testAccessingUndefinedAttributeViaClassWithOverloadedInit]
from typing import overload
class A:
    @overload
    def __init__(self): pass
    @overload
    def __init__(self, x): pass
A.x # E: "A" has no attribute "x"

[case testAccessMethodOfClassWithOverloadedInit]
from typing import overload, Any
class A:
    @overload
    def __init__(self) -> None: pass
    @overload
    def __init__(self, x: Any) -> None: pass
    def f(self) -> None: pass
A.f(A())
A.f()    # E: Too few arguments for "f" of "A"

[case testAssignmentToClassDataAttribute]
import typing
class B: pass
class A:
    x = None # type: B
A.x = B()
A.x = object()  # E: Incompatible types in assignment (expression has type "object", variable has type "B")

[case testAssignmentToInferredClassDataAttribute]
import typing
class B: pass
class A:
     x = B()
A.x = B()
A.x = A()   # E: Incompatible types in assignment (expression has type "A", variable has type "B")

[case testInitMethodUnbound]

class B: pass
class A:
    def __init__(self, b: B) -> None: pass
a = None # type: A
b = None # type: B
A.__init__(a, b)
A.__init__(b, b) # E: Argument 1 to "__init__" of "A" has incompatible type "B"; expected "A"
A.__init__(a, a) # E: Argument 2 to "__init__" of "A" has incompatible type "A"; expected "B"

[case testAssignToMethodViaClass]
import typing
class A:
    def f(self): pass
A.f = None # E: Cannot assign to a method

[case testAssignToNestedClassViaClass]
import typing
class A:
    class B: pass
A.B = None # E: Cannot assign to a type

[case testAccessingClassAttributeWithTypeInferenceIssue]
x = C.x # E: Cannot determine type of 'x'
def f() -> int: return 1
class C:
    x = f()
[builtins fixtures/list.pyi]

[case testAccessingClassAttributeWithTypeInferenceIssue2]
class C:
    x = []
x = C.x
[builtins fixtures/list.pyi]
[out]
main:2: error: Need type annotation for variable


-- Nested classes
-- --------------


[case testClassWithinFunction]

def f() -> None:
    class A:
        def g(self) -> None: pass
    a = None # type: A
    a.g()
    a.g(a) # E: Too many arguments for "g" of "A"
[out]

[case testConstructNestedClass]
import typing
class A:
    class B: pass
    b = B()
    b = A() # E: Incompatible types in assignment (expression has type "A", variable has type "B")
    b = B(b) # E: Too many arguments for "B"
[out]

[case testConstructNestedClassWithCustomInit]
import typing
class A:
    def f(self) -> None:
        class B:
            def __init__(self, a: 'A') -> None: pass
        b = B(A())
        b = A() # E: Incompatible types in assignment (expression has type "A", variable has type "B")
        b = B() # E: Too few arguments for "B"
[out]

[case testDeclareVariableWithNestedClassType]

def f() -> None:
    class A: pass
    a = None # type: A
    a = A()
    a = object() # E: Incompatible types in assignment (expression has type "object", variable has type "A")
[out]

[case testExternalReferenceToClassWithinClass]

class A:
    class B: pass
b = None # type: A.B
b = A.B()
b = A() # E: Incompatible types in assignment (expression has type "A", variable has type "B")
b = A.B(b) # E: Too many arguments for "B"


-- Declaring attribute type in method
-- ----------------------------------


[case testDeclareAttributeTypeInInit]

class A:
    def __init__(self):
        self.x = None # type: int
a = None # type: A
a.x = 1
a.x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")

[case testAccessAttributeDeclaredInInitBeforeDeclaration]

a = None # type: A
a.x = 1
a.x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")
class A:
    def __init__(self):
        self.x = None # type: int


-- Special cases
-- -------------


[case testMultipleClassDefinition]
import typing
A()
class A: pass
class A: pass
[out]
main:4: error: Name 'A' already defined

[case testDocstringInClass]
import typing
class A:
    """Foo"""
class B:
    'x'
    y = B()
[builtins fixtures/primitives.pyi]

[case testErrorMessageInFunctionNestedWithinMethod]
import typing
class A:
    def f(self) -> None:
        def g() -> None:
            a = None
        b = None
[out]
main:5: error: Need type annotation for variable
main:6: error: Need type annotation for variable


-- Static methods
-- --------------


[case testSimpleStaticMethod]
import typing
class A:
  @staticmethod
  def f(x: int) -> None: pass
A.f(1)
A().f(1)
A.f('') # E: Argument 1 to "f" of "A" has incompatible type "str"; expected "int"
A().f('') # E: Argument 1 to "f" of "A" has incompatible type "str"; expected "int"
[builtins fixtures/staticmethod.pyi]

[case testBuiltinStaticMethod]
import typing
int.from_bytes(b'', '')
int.from_bytes('', '') # E: Argument 1 to "from_bytes" of "int" has incompatible type "str"; expected "bytes"
[builtins fixtures/staticmethod.pyi]

[case testAssignStaticMethodOnInstance]
import typing
class A:
  @staticmethod
  def f(x: int) -> None: pass
A().f = A.f # E: Cannot assign to a method
[builtins fixtures/staticmethod.pyi]


-- Class methods
-- -------------


[case testSimpleClassMethod]
import typing
class A:
  @classmethod
  def f(cls, x: int) -> None: pass
A.f(1)
A().f(1)
A.f('') # E: Argument 1 to "f" of "A" has incompatible type "str"; expected "int"
A().f('') # E: Argument 1 to "f" of "A" has incompatible type "str"; expected "int"
[builtins fixtures/classmethod.pyi]

[case testBuiltinClassMethod]
import typing
int.from_bytes(b'', '')
int.from_bytes('', '') # E: Argument 1 to "from_bytes" of "int" has incompatible type "str"; expected "bytes"
[builtins fixtures/classmethod.pyi]

[case testAssignClassMethodOnClass]
import typing
class A:
  @classmethod
  def f(cls, x: int) -> None: pass
A.f = A.f # E: Cannot assign to a method
[builtins fixtures/classmethod.pyi]

[case testAssignClassMethodOnInstance]
import typing
class A:
  @classmethod
  def f(cls, x: int) -> None: pass
A().f = A.f # E: Cannot assign to a method
[builtins fixtures/classmethod.pyi]

[case testClassMethodCalledInClassMethod]
import typing
class C:
  @classmethod
  def foo(cls) -> None: pass
  @classmethod
  def bar(cls) -> None:
    cls()
    cls(1)      # E: Too many arguments for "C"
    cls.bar()
    cls.bar(1)  # E: Too many arguments for "bar" of "C"
    cls.bozo()  # E: "C" has no attribute "bozo"
[builtins fixtures/classmethod.pyi]
[out]

[case testClassMethodCalledOnClass]
import typing
class C:
  @classmethod
  def foo(cls) -> None: pass
C.foo()
C.foo(1)  # E: Too many arguments for "foo" of "C"
C.bozo()  # E: "C" has no attribute "bozo"
[builtins fixtures/classmethod.pyi]

[case testClassMethodCalledOnInstance]
import typing
class C:
  @classmethod
  def foo(cls) -> None: pass
C().foo()
C().foo(1)  # E: Too many arguments for "foo" of "C"
C.bozo()    # E: "C" has no attribute "bozo"
[builtins fixtures/classmethod.pyi]

[case testClassMethodMayCallAbstractMethod]
from abc import abstractmethod
import typing
class C:
  @classmethod
  def foo(cls) -> None:
      cls().bar()
  @abstractmethod
  def bar(self) -> None:
      pass
[builtins fixtures/classmethod.pyi]


-- Properties
-- ----------


[case testAccessingReadOnlyProperty]
import typing
class A:
    @property
    def f(self) -> str: pass
a = A()
reveal_type(a.f)  # E: Revealed type is 'builtins.str'
[builtins fixtures/property.pyi]

[case testAssigningToReadOnlyProperty]
import typing
class A:
    @property
    def f(self) -> str: pass
A().f = '' # E: Property "f" defined in "A" is read-only
[builtins fixtures/property.pyi]

[case testPropertyGetterBody]
import typing
class A:
    @property
    def f(self) -> str:
        self.x = 1
        self.x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")
[builtins fixtures/property.pyi]
[out]

[case testDynamicallyTypedProperty]
import typing
class A:
    @property
    def f(self): pass
a = A()
a.f.xx
a.f = '' # E: Property "f" defined in "A" is read-only
[builtins fixtures/property.pyi]

[case testPropertyWithSetter]
import typing
class A:
    @property
    def f(self) -> int:
        return 1
    @f.setter
    def f(self, x: int) -> None:
        pass
a = A()
a.f = a.f
a.f.x # E: "int" has no attribute "x"
a.f = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")
[builtins fixtures/property.pyi]

[case testPropertyWithDeleterButNoSetter]
import typing
class A:
    @property
    def f(self) -> int:
        return 1
    @f.deleter
    def f(self, x) -> None:
        pass
a = A()
a.f = a.f # E: Property "f" defined in "A" is read-only
a.f.x # E: "int" has no attribute "x"
[builtins fixtures/property.pyi]

-- Descriptors
-- -----------


[case testAccessingNonDataDescriptor]
from typing import Any
class D:
    def __get__(self, inst: Any, own: Any) -> str: return 's'
class A:
    f = D()
a = A()
reveal_type(a.f)  # E: Revealed type is 'builtins.str'

[case testSettingNonDataDescriptor]
from typing import Any
class D:
    def __get__(self, inst: Any, own: Any) -> str: return 's'
class A:
    f = D()
a = A()
a.f = 'foo'
a.f = D()  # E: Incompatible types in assignment (expression has type "D", variable has type "str")

[case testSettingDataDescriptor]
from typing import Any
class D:
    def __get__(self, inst: Any, own: Any) -> str: return 's'
    def __set__(self, inst: Any, value: str) -> None: pass
class A:
    f = D()
a = A()
a.f = ''
a.f = 1 # E: Argument 2 to "__set__" of "D" has incompatible type "int"; expected "str"

[case testReadingDescriptorWithoutDunderGet]
from typing import Union, Any
class D:
    def __set__(self, inst: Any, value: str) -> None: pass
class A:
    f = D()
    def __init__(self): self.f = 's'
a = A()
reveal_type(a.f)  # E: Revealed type is '__main__.D'

[case testAccessingDescriptorFromClass]
# flags: --strict-optional
from d import D, Base
class A(Base):
    f = D()
reveal_type(A.f)  # E: Revealed type is 'd.D'
reveal_type(A().f)  # E: Revealed type is 'builtins.str'
[file d.pyi]
from typing import TypeVar, Type, Generic, overload
class Base: pass
class D:
    def __init__(self) -> None: pass
    @overload
    def __get__(self, inst: None, own: Type[Base]) -> D: pass
    @overload
    def __get__(self, inst: Base, own: Type[Base]) -> str: pass
[builtins fixtures/bool.pyi]

[case testAccessingDescriptorFromClassWrongBase]
# flags: --strict-optional
from d import D, Base
class A:
    f = D()
reveal_type(A.f)
reveal_type(A().f)
[file d.pyi]
from typing import TypeVar, Type, Generic, overload
class Base: pass
class D:
    def __init__(self) -> None: pass
    @overload
    def __get__(self, inst: None, own: Type[Base]) -> D: pass
    @overload
    def __get__(self, inst: Base, own: Type[Base]) -> str: pass
[builtins fixtures/bool.pyi]
[out]
main:5: error: Revealed type is 'Any'
main:5: error: No overload variant of "__get__" of "D" matches argument types [builtins.None, Type[__main__.A]]
main:6: error: Revealed type is 'Any'
main:6: error: No overload variant of "__get__" of "D" matches argument types [__main__.A, Type[__main__.A]]


[case testAccessingGenericNonDataDescriptor]
from typing import TypeVar, Type, Generic, Any
V = TypeVar('V')
class D(Generic[V]):
    def __init__(self, v: V) -> None: self.v = v
    def __get__(self, inst: Any, own: Type) -> V: return self.v
class A:
    f = D(10)
    g = D('10')
a = A()
reveal_type(a.f)  # E: Revealed type is 'builtins.int*'
reveal_type(a.g)  # E: Revealed type is 'builtins.str*'

[case testSettingGenericDataDescriptor]
from typing import TypeVar, Type, Generic, Any
V = TypeVar('V')
class D(Generic[V]):
    def __init__(self, v: V) -> None: self.v = v
    def __get__(self, inst: Any, own: Type) -> V: return self.v
    def __set__(self, inst: Any, v: V) -> None: pass
class A:
    f = D(10)
    g = D('10')
a = A()
a.f = 1
a.f = '' # E: Argument 2 to "__set__" of "D" has incompatible type "str"; expected "int"
a.g = ''
a.g = 1 # E: Argument 2 to "__set__" of "D" has incompatible type "int"; expected "str"

[case testAccessingGenericDescriptorFromClass]
# flags: --strict-optional
from d import D
class A:
    f = D(10)  # type: D[A, int]
    g = D('10')  # type: D[A, str]
reveal_type(A.f)  # E: Revealed type is 'd.D[__main__.A*, builtins.int*]'
reveal_type(A.g)  # E: Revealed type is 'd.D[__main__.A*, builtins.str*]'
reveal_type(A().f)  # E: Revealed type is 'builtins.int*'
reveal_type(A().g)  # E: Revealed type is 'builtins.str*'
[file d.pyi]
from typing import TypeVar, Type, Generic, overload
T = TypeVar('T')
V = TypeVar('V')
class D(Generic[T, V]):
    def __init__(self, v: V) -> None: pass
    @overload
    def __get__(self, inst: None, own: Type[T]) -> 'D[T, V]': pass
    @overload
    def __get__(self, inst: T, own: Type[T]) -> V: pass
[builtins fixtures/bool.pyi]

[case testAccessingGenericDescriptorFromInferredClass]
# flags: --strict-optional
from typing import Type
from d import D
class A:
    f = D(10)  # type: D[A, int]
    g = D('10')  # type: D[A, str]
def f(some_class: Type[A]):
    reveal_type(some_class.f)
    reveal_type(some_class.g)
[file d.pyi]
from typing import TypeVar, Type, Generic, overload
T = TypeVar('T')
V = TypeVar('V')
class D(Generic[T, V]):
    def __init__(self, v: V) -> None: pass
    @overload
    def __get__(self, inst: None, own: Type[T]) -> 'D[T, V]': pass
    @overload
    def __get__(self, inst: T, own: Type[T]) -> V: pass
[builtins fixtures/bool.pyi]
[out]
main:8: error: Revealed type is 'd.D[__main__.A*, builtins.int*]'
main:9: error: Revealed type is 'd.D[__main__.A*, builtins.str*]'

[case testAccessingGenericDescriptorFromClassBadOverload]
# flags: --strict-optional
from d import D
class A:
    f = D(10)  # type: D[A, int]
reveal_type(A.f)
[file d.pyi]
from typing import TypeVar, Type, Generic, overload
T = TypeVar('T')
V = TypeVar('V')
class D(Generic[T, V]):
    def __init__(self, v: V) -> None: pass
    @overload
    def __get__(self, inst: None, own: None) -> 'D[T, V]': pass
    @overload
    def __get__(self, inst: T, own: Type[T]) -> V: pass
[builtins fixtures/bool.pyi]
[out]
main:5: error: Revealed type is 'Any'
main:5: error: No overload variant of "__get__" of "D" matches argument types [builtins.None, Type[__main__.A]]

[case testAccessingNonDataDescriptorSubclass]
from typing import Any
class C:
    def __get__(self, inst: Any, own: Any) -> str: return 's'
class D(C): pass
class A:
    f = D()
a = A()
reveal_type(a.f)  # E: Revealed type is 'builtins.str'

[case testSettingDataDescriptorSubclass]
from typing import Any
class C:
    def __get__(self, inst: Any, own: Any) -> str: return 's'
    def __set__(self, inst: Any, v: str) -> None: pass
class D(C): pass
class A:
    f = D()
a = A()
a.f = ''
a.f = 1 # E: Argument 2 to "__set__" of "C" has incompatible type "int"; expected "str"

[case testReadingDescriptorSubclassWithoutDunderGet]
from typing import Union, Any
class C:
    def __set__(self, inst: Any, v: str) -> None: pass
class D(C): pass
class A:
    f = D()
    def __init__(self): self.f = 's'
a = A()
reveal_type(a.f)  # E: Revealed type is '__main__.D'

[case testAccessingGenericNonDataDescriptorSubclass]
from typing import TypeVar, Type, Generic, Any
V = TypeVar('V')
class C(Generic[V]):
    def __init__(self, v: V) -> None: self.v = v
    def __get__(self, inst: Any, own: Type) -> V: return self.v
class D(C[V], Generic[V]): pass
class A:
    f = D(10)
    g = D('10')
a = A()
reveal_type(a.f)  # E: Revealed type is 'builtins.int*'
reveal_type(a.g)  # E: Revealed type is 'builtins.str*'

[case testSettingGenericDataDescriptorSubclass]
from typing import TypeVar, Type, Generic
T = TypeVar('T')
V = TypeVar('V')
class C(Generic[T, V]):
    def __init__(self, v: V) -> None: self.v = v
    def __get__(self, inst: T, own: Type[T]) -> V: return self.v
    def __set__(self, inst: T, v: V) -> None: pass
class D(C[T, V], Generic[T, V]): pass
class A:
    f = D(10)  # type: D[A, int]
    g = D('10')  # type: D[A, str]
a = A()
a.f = 1
a.f = '' # E: Argument 2 to "__set__" of "C" has incompatible type "str"; expected "int"
a.g = ''
a.g = 1 # E: Argument 2 to "__set__" of "C" has incompatible type "int"; expected "str"

[case testSetDescriptorOnClass]
from typing import TypeVar, Type, Generic
T = TypeVar('T')
V = TypeVar('V')
class D(Generic[T, V]):
    def __init__(self, v: V) -> None: self.v = v
    def __get__(self, inst: T, own: Type[T]) -> V: return self.v
    def __set__(self, inst: T, v: V) -> None: pass
class A:
    f = D(10)  # type: D[A, int]
A.f = D(20)
A.f = D('some string')  # E: Argument 1 to "D" has incompatible type "str"; expected "int"

[case testSetDescriptorOnInferredClass]
from typing import TypeVar, Type, Generic, Any
V = TypeVar('V')
class D(Generic[V]):
    def __init__(self, v: V) -> None: self.v = v
    def __get__(self, inst: Any, own: Type) -> V: return self.v
    def __set__(self, inst: Any, v: V) -> None: pass
class A:
    f = D(10)
def f(some_class: Type[A]):
    A.f = D(20)
    A.f = D('some string')
[out]
main:11: error: Argument 1 to "D" has incompatible type "str"; expected "int"

[case testDescriptorUncallableDunderSet]
class D:
    __set__ = 's'
class A:
    f = D()
A().f = 'x'  # E: __main__.D.__set__ is not callable

[case testDescriptorDunderSetTooFewArgs]
class D:
    def __set__(self, inst): pass
class A:
    f = D()
A().f = 'x'  # E: Too many arguments for "__set__"

[case testDescriptorDunderSetTooManyArgs]
class D:
    def __set__(self, inst, v, other): pass
class A:
    f = D()
A().f = 'x'  # E: Too few arguments for "__set__"

[case testDescriptorDunderSetWrongArgTypes]
class D:
    def __set__(self, inst: str, v:str) -> None: pass
class A:
    f = D()
A().f = 'x'  # E: Argument 1 to "__set__" of "D" has incompatible type "A"; expected "str"

[case testDescriptorUncallableDunderGet]
class D:
    __get__ = 's'
class A:
    f = D()
A().f  # E: __main__.D.__get__ is not callable

[case testDescriptorDunderGetTooFewArgs]
class D:
    def __get__(self, inst): pass
class A:
    f = D()
A().f  # E: Too many arguments for "__get__"

[case testDescriptorDunderGetTooManyArgs]
class D:
    def __get__(self, inst, own, other): pass
class A:
    f = D()
A().f = 'x'  # E: Too few arguments for "__get__"

[case testDescriptorDunderGetWrongArgTypeForInstance]
from typing import Any
class D:
    def __get__(self, inst: str, own: Any) -> Any: pass
class A:
    f = D()
A().f  # E: Argument 1 to "__get__" of "D" has incompatible type "A"; expected "str"

[case testDescriptorDunderGetWrongArgTypeForOwner]
from typing import Any
class D:
    def __get__(self, inst: Any, own: str) -> Any: pass
class A:
    f = D()
A().f  # E: Argument 2 to "__get__" of "D" has incompatible type Type[A]; expected "str"

[case testDescriptorGetSetDifferentTypes]
from typing import Any
class D:
    def __get__(self, inst: Any, own: Any) -> str: return 's'
    def __set__(self, inst: Any, v: int) -> None: pass
class A:
    f = D()
a = A()
a.f = 1
reveal_type(a.f)  # E: Revealed type is 'builtins.str'


-- _promote decorators
-- -------------------


[case testSimpleDucktypeDecorator]
from typing import _promote
class A: pass
@_promote(A)
class B: pass
a = None  # type: A
b = None  # type: B
b = a # E: Incompatible types in assignment (expression has type "A", variable has type "B")
a = b

[case testDucktypeTransitivityDecorator]
from typing import _promote
class A: pass
@_promote(A)
class B: pass
@_promote(B)
class C: pass
a = None  # type: A
c = None  # type: C
c = a # E: Incompatible types in assignment (expression has type "A", variable has type "C")
a = c


-- Hard coded type promotions
-- --------------------------

[case testHardCodedTypePromotions]
import typing
def f(x: float) -> None: pass
def g(x: complex) -> None: pass
f(1)
g(1)
g(1.1)
[builtins fixtures/complex.pyi]


-- Operator methods
-- ----------------


[case testOperatorMethodOverrideIntroducingOverloading]
from typing import overload
class A:
    def __add__(self, x: int) -> int: pass
class B(A):
    @overload  # E: Signature of "__add__" incompatible with supertype "A"
    def __add__(self, x: int) -> int: pass
    @overload
    def __add__(self, x: str) -> str: pass
[out]

[case testOperatorMethodOverrideWideningArgumentType]
import typing
class A:
    def __add__(self, x: int) -> int: pass
class B(A):
    def __add__(self, x: object) -> int: pass
[out]

[case testOperatorMethodOverrideNarrowingReturnType]
import typing
class A:
    def __add__(self, x: int) -> 'A': pass
class B(A):
    def __add__(self, x: int) -> 'B': pass

[case testOperatorMethodOverrideWithDynamicallyTyped]
import typing
class A:
    def __add__(self, x: int) -> 'A': pass
class B(A):
    def __add__(self, x): pass

[case testOperatorMethodOverrideWithIdenticalOverloadedType]
from typing import overload
class A:
    @overload
    def __add__(self, x: int) -> 'A': pass
    @overload
    def __add__(self, x: str) -> 'A': pass
class B(A):
    @overload
    def __add__(self, x: int) -> 'A': pass
    @overload
    def __add__(self, x: str) -> 'A': pass

[case testOverloadedOperatorMethodOverrideWithDynamicallyTypedMethod]
from typing import overload, Any
class A:
    @overload
    def __add__(self, x: int) -> 'A': pass
    @overload
    def __add__(self, x: str) -> 'A': pass
class B(A):
    def __add__(self, x): pass
class C(A):
    def __add__(self, x: Any) -> A: pass

[case testOverloadedOperatorMethodOverrideWithNewItem]
from typing import overload, Any
class A:
    @overload
    def __add__(self, x: int) -> 'A': pass
    @overload
    def __add__(self, x: str) -> 'A': pass
class B(A):
    @overload
    def __add__(self, x: int) -> A: pass
    @overload
    def __add__(self, x: str) -> A: pass
    @overload
    def __add__(self, x: type) -> A: pass
[out]
main:8: error: Signature of "__add__" incompatible with supertype "A"

[case testOverloadedOperatorMethodOverrideWithSwitchedItemOrder]
from typing import overload, Any
class A:
    @overload
    def __add__(self, x: 'B') -> 'B': pass
    @overload
    def __add__(self, x: 'A') -> 'A': pass
class B(A):
    @overload
    def __add__(self, x: 'A') -> 'A': pass
    @overload
    def __add__(self, x: 'B') -> 'B': pass
[out]
main:8: error: Signature of "__add__" incompatible with supertype "A"

[case testReverseOperatorMethodArgumentType]
from typing import Any
class A: pass
class B:
    def __radd__(self, x: A) -> int: pass # Error
class C:
    def __radd__(self, x: A) -> Any: pass
class D:
    def __radd__(self, x: A) -> object: pass
[out]

[case testReverseOperatorMethodArgumentType2]
from typing import Any, Tuple, Callable
class A:
    def __radd__(self, x: Tuple[int, str]) -> int: pass
class B:
    def __radd__(self, x: Callable[[], int]) -> int: pass
class C:
    def __radd__(self, x: Any) -> int: pass
[out]

[case testReverseOperatorMethodForwardIsAny]
from typing import Any
def deco(f: Any) -> Any: return f
class C:
    @deco
    def __add__(self, other: C) -> C: return C()
    def __radd__(self, other: C) -> C: return C()
[out]

[case testReverseOperatorMethodForwardIsAny2]
from typing import Any
def deco(f: Any) -> Any: return f
class C:
    __add__ = None  # type: Any
    def __radd__(self, other: C) -> C: return C()
[out]

[case testReverseOperatorMethodForwardIsAny3]
from typing import Any
def deco(f: Any) -> Any: return f
class C:
    __add__ = 42
    def __radd__(self, other: C) -> C: return C()
[out]
main:5: error: Forward operator "__add__" is not callable

[case testOverloadedReverseOperatorMethodArgumentType]
from typing import overload, Any
class A:
    @overload
    def __radd__(self, x: 'A') -> str: pass # Error
    @overload
    def __radd__(self, x: 'A') -> Any: pass
[out]

[case testReverseOperatorMethodArgumentTypeAndOverloadedMethod]
from typing import overload
class A:
    @overload
    def __add__(self, x: int) -> int: pass
    @overload
    def __add__(self, x: str) -> int: pass
    def __radd__(self, x: 'A') -> str: pass

[case testAbstractReverseOperatorMethod]
import typing
from abc import abstractmethod
class A:
    @abstractmethod
    def __lt__(self, x: 'A') -> int: pass
class B:
    @abstractmethod
    def __lt__(self, x: 'B') -> int: pass
    @abstractmethod
    def __gt__(self, x: 'B') -> int: pass
[out]

[case testOperatorMethodsAndOverloadingSpecialCase]
from typing import overload
class A:
    @overload
    def __add__(self, x: 'A') -> int: pass
    @overload
    def __add__(self, x: str) -> int: pass
class B:
    def __radd__(self, x: 'A') -> str: pass
[out]

[case testUnsafeOverlappingWithOperatorMethodsAndOverloading2]
from typing import overload
class A:
    def __add__(self, x: 'A') -> int: pass
class B:
    @overload
    def __radd__(self, x: 'X') -> str: pass # Error
    @overload
    def __radd__(self, x: A) -> str: pass   # Error
class X:
    def __add__(self, x): pass
[out]
main:6: error: Signatures of "__radd__" of "B" and "__add__" of "X" are unsafely overlapping

[case testUnsafeOverlappingWithLineNo]
from typing import TypeVar
T = TypeVar('T', Real)
class Real:
    def __add__(self, other): ...
class Fraction(Real):
    def __radd__(self, other: T) -> T: ...
[out]
main:6: error: Signatures of "__radd__" of "Fraction" and "__add__" of "Real" are unsafely overlapping

[case testOverlappingNormalAndInplaceOperatorMethod]
import typing
class A:
    # Incompatible (potential trouble with __radd__)
    def __add__(self, x: 'A') -> int: pass
    def __iadd__(self, x: 'B') -> int: pass
class B:
    # Safe
    def __add__(self, x: 'C') -> int: pass
    def __iadd__(self, x: A) -> int: pass
class C(A): pass
[out]
main:5: error: Signatures of "__iadd__" and "__add__" are incompatible

[case testOverloadedNormalAndInplaceOperatorMethod]
from typing import overload
class A:
    @overload
    def __add__(self, x: int) -> int: pass
    @overload
    def __add__(self, x: str) -> int: pass
    @overload # Error
    def __iadd__(self, x: int) -> int: pass
    @overload
    def __iadd__(self, x: object) -> int: pass
class B:
    @overload
    def __add__(self, x: int) -> int: pass
    @overload
    def __add__(self, x: str) -> str: pass
    @overload
    def __iadd__(self, x: int) -> int: pass
    @overload
    def __iadd__(self, x: str) -> str: pass
[out]
main:7: error: Signatures of "__iadd__" and "__add__" are incompatible

[case testIntroducingInplaceOperatorInSubclass]
import typing
class A:
    def __add__(self, x: 'A') -> 'B': pass
class B(A):
    # __iadd__ effectively partially overrides __add__
    def __iadd__(self, x: 'A') -> 'A': pass # Error
class C(A):
    def __iadd__(self, x: int) -> 'B': pass # Error
class D(A):
    def __iadd__(self, x: 'A') -> 'B': pass
[out]
main:6: error: Return type of "__iadd__" incompatible with "__add__" of supertype "A"
main:8: error: Argument 1 of "__iadd__" incompatible with "__add__" of supertype "A"
main:8: error: Signatures of "__iadd__" and "__add__" are incompatible


[case testGetAttr]

a, b = None, None # type: A, B
class A:
    def __getattr__(self, x: str) -> A:
        return A()
class B: pass

a = a.foo
b = a.bar
[out]
main:9: error: Incompatible types in assignment (expression has type "A", variable has type "B")


[case testGetAttrSignature]
class A:
    def __getattr__(self, x: str) -> A: pass
class B:
    def __getattr__(self, x: A) -> B: pass
class C:
    def __getattr__(self, x: str, y: str) -> C: pass
class D:
    def __getattr__(self, x: str) -> None: pass
[out]
main:4: error: Invalid signature "def (__main__.B, __main__.A) -> __main__.B"
main:6: error: Invalid signature "def (__main__.C, builtins.str, builtins.str) -> __main__.C"


-- CallableType objects
-- ----------------


[case testCallableObject]
import typing
a = A()
b = B()

a()  # E: Too few arguments for "__call__" of "A"
a(a, a)  # E: Too many arguments for "__call__" of "A"
a = a(a)
a = a(b)  # E: Argument 1 to "__call__" of "A" has incompatible type "B"; expected "A"
b = a(a)  # E: Incompatible types in assignment (expression has type "A", variable has type "B")

class A:
    def __call__(self, x: A) -> A:
        pass
class B: pass


-- __new__
-- --------


[case testConstructInstanceWith__new__]
class C:
    def __new__(cls, foo: int = None) -> 'C':
        obj = object.__new__(cls)
        return obj

x = C(foo=12)
x.a # E: "C" has no attribute "a"
C(foo='') # E: Argument 1 to "C" has incompatible type "str"; expected "int"
[builtins fixtures/__new__.pyi]

[case testConstructInstanceWithDynamicallyTyped__new__]
class C:
    def __new__(cls, foo):
        obj = object.__new__(cls)
        return obj

x = C(foo=12)
x = C(foo='x')
x.a # E: "C" has no attribute "a"
C(bar='') # E: Unexpected keyword argument "bar" for "C"
[builtins fixtures/__new__.pyi]

[case testClassWith__new__AndCompatibilityWithType]
class C:
    def __new__(cls, foo: int = None) -> 'C':
        obj = object.__new__(cls)
        return obj
def f(x: type) -> None: pass
def g(x: int) -> None: pass
f(C)
g(C) # E: Argument 1 to "g" has incompatible type "C"; expected "int"
[builtins fixtures/__new__.pyi]

[case testClassWith__new__AndCompatibilityWithType2]
class C:
    def __new__(cls, foo):
        obj = object.__new__(cls)
        return obj
def f(x: type) -> None: pass
def g(x: int) -> None: pass
f(C)
g(C) # E: Argument 1 to "g" has incompatible type "C"; expected "int"
[builtins fixtures/__new__.pyi]

[case testGenericClassWith__new__]
from typing import TypeVar, Generic
T = TypeVar('T')
class C(Generic[T]):
    def __new__(cls, foo: T) -> 'C[T]':
        obj = object.__new__(cls)
        return obj
    def set(self, x: T) -> None: pass
c = C('')
c.set('')
c.set(1) # E: Argument 1 to "set" of "C" has incompatible type "int"; expected "str"
[builtins fixtures/__new__.pyi]

[case testOverloaded__new__]
from typing import overload
class C:
    @overload
    def __new__(cls, foo: int) -> 'C':
        obj = object.__new__(cls)
        return obj
    @overload
    def __new__(cls, x: str, y: str) -> 'C':
        obj = object.__new__(cls)
        return obj
c = C(1)
c.a # E: "C" has no attribute "a"
C('', '')
C('') # E: No overload variant of "C" matches argument types [builtins.str]
[builtins fixtures/__new__.pyi]


-- Special cases
-- -------------


[case testSubclassInt]
import typing
class A(int): pass
n = 0
n = A()
a = A()
a = 0 # E: Incompatible types in assignment (expression has type "int", variable has type "A")

[case testForwardReferenceToNestedClass]
def f(o: 'B.C') -> None:
    o.f('') # E: Argument 1 to "f" of "C" has incompatible type "str"; expected "int"

class B:
    class C:
        def f(self, x: int) -> None: pass
[out]

[case testForwardReferenceToNestedClassDeep]
def f(o: 'B.C.D') -> None:
    o.f('') # E: Argument 1 to "f" of "D" has incompatible type "str"; expected "int"

class B:
    class C:
        class D:
            def f(self, x: int) -> None: pass
[out]

[case testForwardReferenceToNestedClassWithinClass]
class B:
    def f(self, o: 'C.D') -> None:
        o.f('') # E: Argument 1 to "f" of "D" has incompatible type "str"; expected "int"

    class C:
        class D:
            def f(self, x: int) -> None: pass
[out]

[case testClassVsInstanceDisambiguation]
class A: pass
def f(x: A) -> None: pass
f(A) # E: Argument 1 to "f" has incompatible type "A" (type object); expected "A"
[out]

-- TODO
--   attribute inherited from superclass; assign in __init__
--   refer to attribute before type has been inferred (the initialization in
--   __init__ has not been analyzed)

[case testAnyBaseClassUnconstrainedConstructor]
from typing import Any
B = None  # type: Any
class C(B): pass
C(0)
C(arg=0)
[out]

[case testErrorMapToSupertype]
import typing
class X(Nope): pass  # E: Name 'Nope' is not defined
a, b = X()  # Used to crash here (#2244)


-- Class-valued attributes
-- -----------------------

[case testClassValuedAttributesBasics]
class A: ...
class B:
    a = A
    bad = lambda: 42

B().bad() # E: Invalid method type
reveal_type(B.a) # E: Revealed type is 'def () -> __main__.A'
reveal_type(B().a) # E: Revealed type is 'def () -> __main__.A'
reveal_type(B().a()) # E: Revealed type is '__main__.A'

class C:
    a = A
    def __init__(self) -> None:
        self.aa = self.a()

reveal_type(C().aa) # E: Revealed type is '__main__.A'
[out]

[case testClassValuedAttributesGeneric]
from typing import Generic, TypeVar
T = TypeVar('T')

class A(Generic[T]):
    def __init__(self, x: T) -> None:
        self.x = x
class B(Generic[T]):
    a = A[T]

reveal_type(B[int]().a) # E: Revealed type is 'def (x: builtins.int*) -> __main__.A[builtins.int*]'
B[int]().a('hi') # E: Argument 1 has incompatible type "str"; expected "int"

class C(Generic[T]):
    a = A
    def __init__(self) -> None:
        self.aa = self.a(42)

reveal_type(C().aa) # E: Revealed type is '__main__.A[builtins.int]'
[out]

[case testClassValuedAttributesAlias]
from typing import Generic, TypeVar
T = TypeVar('T')
S = TypeVar('S')

class A(Generic[T, S]): ...

SameA = A[T, T]

class B:
    a_any = SameA
    a_int = SameA[int]

reveal_type(B().a_any) # E: Revealed type is 'def () -> __main__.A[Any, Any]'
reveal_type(B().a_int()) # E: Revealed type is '__main__.A[builtins.int*, builtins.int*]'

class C:
    a_int = SameA[int]
    def __init__(self) -> None:
        self.aa = self.a_int()

reveal_type(C().aa) # E: Revealed type is '__main__.A[builtins.int*, builtins.int*]'
[out]


-- Type[C]
-- -------


[case testTypeUsingTypeCBasic]
from typing import Type
class User: pass
class ProUser(User): pass
def new_user(user_class: Type[User]) -> User:
    return user_class()
reveal_type(new_user(User))  # E: Revealed type is '__main__.User'
reveal_type(new_user(ProUser))  # E: Revealed type is '__main__.User'
[out]

[case testTypeUsingTypeCDefaultInit]
from typing import Type
class B:
    pass
def f(A: Type[B]) -> None:
    A(0)  # E: Too many arguments for "B"
    A()
[out]

[case testTypeUsingTypeCInitWithArg]
from typing import Type
class B:
    def __init__(self, a: int) -> None: pass
def f(A: Type[B]) -> None:
    A(0)
    A()  # E: Too few arguments for "B"
[out]

[case testTypeUsingTypeCTypeVar]
from typing import Type, TypeVar
class User: pass
class ProUser(User): pass
U = TypeVar('U', bound=User)
def new_user(user_class: Type[U]) -> U:
    user = user_class()
    reveal_type(user)
    return user
pro_user = new_user(ProUser)
reveal_type(pro_user)
[out]
main:7: error: Revealed type is 'U`-1'
main:10: error: Revealed type is '__main__.ProUser*'

[case testTypeUsingTypeCTypeVarDefaultInit]
from typing import Type, TypeVar
class B:
    pass
T = TypeVar('T', bound=B)
def f(A: Type[T]) -> None:
    A()
    A(0)  # E: Too many arguments for "B"
[out]

[case testTypeUsingTypeCTypeVarWithInit]
from typing import Type, TypeVar
class B:
    def __init__(self, a: int) -> None: pass
T = TypeVar('T', bound=B)
def f(A: Type[T]) -> None:
    A()  # E: Too few arguments for "B"
    A(0)
[out]

[case testTypeUsingTypeCTwoTypeVars]
from typing import Type, TypeVar
class User: pass
class ProUser(User): pass
class WizUser(ProUser): pass
U = TypeVar('U', bound=User)
def new_user(u_c: Type[U]) -> U: pass
P = TypeVar('P', bound=ProUser)
def new_pro(pro_c: Type[P]) -> P:
    return new_user(pro_c)
wiz = new_pro(WizUser)
reveal_type(wiz)
def error(u_c: Type[U]) -> P:
    return new_pro(u_c)  # Error here, see below
[out]
main:11: error: Revealed type is '__main__.WizUser*'
main:13: error: Incompatible return value type (got "U", expected "P")
main:13: error: Type argument 1 of "new_pro" has incompatible value "U"

[case testTypeUsingTypeCCovariance]
from typing import Type, TypeVar
class User: pass
class ProUser(User): pass
def new_user(user_class: Type[User]) -> User:
    return user_class()
def new_pro_user(user_class: Type[ProUser]):
    new_user(user_class)
[out]

[case testTypeUsingTypeCErrorCovariance]
from typing import Type, TypeVar
class User: pass
def new_user(user_class: Type[User]):
    return user_class()
def foo(arg: Type[int]):
    new_user(arg)  # E: Argument 1 to "new_user" has incompatible type Type[int]; expected Type[User]
[out]

[case testTypeUsingTypeCUnionOverload]
from typing import Type, Union, overload
class X:
    @overload
    def __init__(self) -> None: pass
    @overload
    def __init__(self, a: int) -> None: pass
class Y:
    def __init__(self) -> None: pass
def bar(o: Type[Union[X, Y]]): pass
bar(X)
bar(Y)
[out]

[case testTypeUsingTypeCTypeAny]
from typing import Type, Any
def foo(arg: Type[Any]):
    x = arg()
    x = arg(0)
    x = arg('', ())
    reveal_type(x)  # E: Revealed type is 'Any'
    x.foo
class X: pass
foo(X)
[out]

[case testTypeUsingTypeCTypeNoArg]
from typing import Type
def foo(arg: Type):
    x = arg()
    reveal_type(x)  # E: Revealed type is 'Any'
class X: pass
foo(X)
[out]

[case testTypeUsingTypeCBuiltinType]
from typing import Type
def foo(arg: type): pass
class X: pass
def bar(arg: Type[X]):
    foo(arg)
foo(X)
[builtins fixtures/tuple.pyi]
[out]

[case testTypeUsingTypeCClassMethod]
from typing import Type
class User:
    @classmethod
    def foo(cls) -> int: pass
    def bar(self) -> int: pass
def process(cls: Type[User]):
    reveal_type(cls.foo())  # E: Revealed type is 'builtins.int'
    obj = cls()
    reveal_type(cls.bar(obj))  # E: Revealed type is 'builtins.int'
    cls.mro()  # Defined in class type
    cls.error  # E: Type[User] has no attribute "error"
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeUsingTypeCClassMethodUnion]
# Ideally this would work, but not worth the effort; just don't crash
from typing import Type, Union
class User:
    @classmethod
    def foo(cls) -> int: pass
    def bar(self) -> int: pass
class ProUser(User): pass
class BasicUser(User): pass
def process(cls: Type[Union[BasicUser, ProUser]]):
    cls.foo()  # E: Type[Union[BasicUser, ProUser]] has no attribute "foo"
    obj = cls()
    cls.bar(obj)  # E: Type[Union[BasicUser, ProUser]] has no attribute "bar"
    cls.mro()  # Defined in class type
    cls.error  # E: Type[Union[BasicUser, ProUser]] has no attribute "error"
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeUsingTypeCClassMethodFromTypeVar]
from typing import Type, TypeVar
class User:
    @classmethod
    def foo(cls) -> int: pass
    def bar(self) -> int: pass
U = TypeVar('U', bound=User)
def process(cls: Type[U]):
    reveal_type(cls.foo())  # E: Revealed type is 'builtins.int'
    obj = cls()
    reveal_type(cls.bar(obj))  # E: Revealed type is 'builtins.int'
    cls.mro()  # Defined in class type
    cls.error  # E: Type[U] has no attribute "error"
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeUsingTypeCClassMethodFromTypeVarUnionBound]
# Ideally this would work, but not worth the effort; just don't crash
from typing import Type, TypeVar, Union
class User:
    @classmethod
    def foo(cls) -> int: pass
    def bar(self) -> int: pass
class ProUser(User): pass
class BasicUser(User): pass
U = TypeVar('U', bound=Union[ProUser, BasicUser])
def process(cls: Type[U]):
    cls.foo()  # E: Type[U] has no attribute "foo"
    obj = cls()
    cls.bar(obj)  # E: Type[U] has no attribute "bar"
    cls.mro()  # Defined in class type
    cls.error  # E: Type[U] has no attribute "error"
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeUsingTypeCErrorUnsupportedType]
from typing import Type, Tuple
def foo(arg: Type[Tuple[int]]):  # E: Unsupported type Type["Tuple[int]"]
    arg()
[builtins fixtures/tuple.pyi]
[out]

[case testTypeUsingTypeCOverloadedClass]
from typing import Type, TypeVar, overload
class User:
    @overload
    def __init__(self) -> None: pass
    @overload
    def __init__(self, arg: int) -> None: pass
    @classmethod
    def foo(cls) -> None: pass
U = TypeVar('U', bound=User)
def new(uc: Type[U]) -> U:
    uc.foo()
    u = uc()
    u.foo()
    u = uc(0)
    u.foo()
    u = uc('')
    u.foo(0)
    return uc()
u = new(User)
[builtins fixtures/classmethod.pyi]
[out]
main:16: error: No overload variant of "User" matches argument types [builtins.str]
main:17: error: Too many arguments for "foo" of "User"

[case testTypeUsingTypeCInUpperBound]
from typing import TypeVar, Type
class B: pass
T = TypeVar('T', bound=Type[B])
def f(a: T): pass
[out]

[case testTypeUsingTypeCTuple]
from typing import Type, Tuple
def f(a: Type[Tuple[int, int]]):
    a()
[out]
main:2: error: Unsupported type Type["Tuple[int, int]"]

[case testTypeUsingTypeCNamedTuple]
from typing import Type, NamedTuple
N = NamedTuple('N', [('x', int), ('y', int)])
def f(a: Type[N]):
    a()
[builtins fixtures/list.pyi]
[out]
main:3: error: Unsupported type Type["N"]

[case testTypeUsingTypeCJoin]
from typing import Type
class B: pass
class C(B): pass
class D(B): pass
def foo(c: Type[C], d: Type[D]) -> None:
    x = [c, d]
    reveal_type(x)

[builtins fixtures/list.pyi]
[out]
main:7: error: Revealed type is 'builtins.list[Type[__main__.B]]'

[case testTypeMatchesOverloadedFunctions]
from typing import Type, overload, Union

class User: pass
UserType = User  # type: Type[User]

@overload
def f(a: object) -> int: pass
@overload
def f(a: int) -> str: pass

reveal_type(f(User))  # E: Revealed type is 'builtins.int'
reveal_type(f(UserType))  # E: Revealed type is 'builtins.int'
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeMatchesGeneralTypeInOverloadedFunctions]
from typing import Type, overload

class User: pass
UserType = User  # type: Type[User]

@overload
def f(a: type) -> int:
    return 1
@overload
def f(a: int) -> str:
    return "a"

reveal_type(f(User))  # E: Revealed type is 'builtins.int'
reveal_type(f(UserType))  # E: Revealed type is 'builtins.int'
reveal_type(f(1))  # E: Revealed type is 'builtins.str'
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeMatchesSpecificTypeInOverloadedFunctions]
from typing import Type, overload

class User: pass
UserType = User  # type: Type[User]

@overload
def f(a: User) -> User:
    return User()
@overload
def f(a: Type[User]) -> int:
    return 1
@overload
def f(a: int) -> str:
    return "a"

reveal_type(f(User))  # E: Revealed type is 'builtins.int'
reveal_type(f(UserType))  # E: Revealed type is 'builtins.int'
reveal_type(f(User()))  # E: Revealed type is '__main__.User'
reveal_type(f(1))  # E: Revealed type is 'builtins.str'
[builtins fixtures/classmethod.pyi]
[out]

[case testMixingTypeTypeInOverloadedFunctions]
from typing import Type, overload

class User: pass

@overload
def f(a: User) -> Type[User]:
    return User
@overload
def f(a: Type[User]) -> User:
    return a()
@overload
def f(a: int) -> Type[User]:
    return User
@overload
def f(a: str) -> User:
    return User()

reveal_type(f(User()))  # E: Revealed type is 'Type[__main__.User]'
reveal_type(f(User))  # E: Revealed type is '__main__.User'
reveal_type(f(3))  # E: Revealed type is 'Type[__main__.User]'
reveal_type(f("hi"))  # E: Revealed type is '__main__.User'
[builtins fixtures/classmethod.pyi]
[out]

[case testGeneralTypeDoesNotMatchSpecificTypeInOverloadedFunctions]
from typing import Type, overload

class User: pass

@overload
def f(a: Type[User]) -> None: pass
@overload
def f(a: int) -> None: pass

def mock() -> type: return User

f(User)
f(mock())  # E: No overload variant of "f" matches argument types [builtins.type]
[builtins fixtures/classmethod.pyi]
[out]

[case testNonTypeDoesNotMatchOverloadedFunctions]
from typing import Type, overload

class User: pass

@overload
def f(a: Type[User]) -> None: pass
@overload
def f(a: type) -> None: pass

f(3)  # E: No overload variant of "f" matches argument types [builtins.int]
[builtins fixtures/classmethod.pyi]
[out]

[case testInstancesDoNotMatchTypeInOverloadedFunctions]
from typing import Type, overload

class User: pass

@overload
def f(a: Type[User]) -> None: pass
@overload
def f(a: int) -> None: pass

f(User)
f(User())  # E: No overload variant of "f" matches argument types [__main__.User]
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeCovarianceWithOverloadedFunctions]
from typing import Type, overload

class A: pass
class B(A): pass
class C(B): pass
AType = A  # type: Type[A]
BType = B  # type: Type[B]
CType = C  # type: Type[C]

@overload
def f(a: Type[B]) -> None: pass
@overload
def f(a: int) -> None: pass

f(A)  # E: No overload variant of "f" matches argument types [def () -> __main__.A]
f(B)
f(C)
f(AType)  # E: No overload variant of "f" matches argument types [Type[__main__.A]]
f(BType)
f(CType)
[builtins fixtures/classmethod.pyi]
[out]


[case testOverloadedCovariantTypesFail]
from typing import Type, overload

class A: pass
class B(A): pass

@overload
def f(a: Type[A]) -> int: pass  # E: Overloaded function signatures 1 and 2 overlap with incompatible return types
@overload
def f(a: Type[B]) -> str: pass
[builtins fixtures/classmethod.pyi]
[out]

[case testDistinctOverloadedCovariantTypesSucceed]
from typing import Type, overload

class A: pass
class AChild(A): pass
class B: pass
class BChild(B): pass

@overload
def f(a: Type[A]) -> int: pass
@overload
def f(a: Type[B]) -> str: pass
@overload
def f(a: A) -> A: pass
@overload
def f(a: B) -> B: pass

reveal_type(f(A))  # E: Revealed type is 'builtins.int'
reveal_type(f(AChild))  # E: Revealed type is 'builtins.int'
reveal_type(f(B))  # E: Revealed type is 'builtins.str'
reveal_type(f(BChild))  # E: Revealed type is 'builtins.str'

reveal_type(f(A()))  # E: Revealed type is '__main__.A'
reveal_type(f(AChild()))  # E: Revealed type is '__main__.A'
reveal_type(f(B()))  # E: Revealed type is '__main__.B'
reveal_type(f(BChild()))  # E: Revealed type is '__main__.B'
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeTypeOverlapsWithObjectAndType]
from typing import Type, overload

class User: pass

@overload
def f(a: Type[User]) -> int: pass  # E: Overloaded function signatures 1 and 2 overlap with incompatible return types
@overload
def f(a: object) -> str: pass

@overload
def g(a: Type[User]) -> int: pass  # E: Overloaded function signatures 1 and 2 overlap with incompatible return types
@overload
def g(a: type) -> str: pass
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeOverlapsWithObject]
from typing import Type, overload

class User: pass

@overload
def f(a: type) -> int: pass  # E: Overloaded function signatures 1 and 2 overlap with incompatible return types
@overload
def f(a: object) -> str: pass
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeConstructorReturnsTypeType]
class User:
    @classmethod
    def test_class_method(cls) -> int: pass
    @staticmethod
    def test_static_method() -> str: pass
    def test_instance_method(self) -> None: pass

u = User()

reveal_type(type(u))  # E: Revealed type is 'Type[__main__.User]'
reveal_type(type(u).test_class_method())  # E: Revealed type is 'builtins.int'
reveal_type(type(u).test_static_method())  # E: Revealed type is 'builtins.str'
type(u).test_instance_method()  # E: Too few arguments for "test_instance_method" of "User"
[builtins fixtures/classmethod.pyi]
[out]

[case testObfuscatedTypeConstructorReturnsTypeType]
from typing import TypeVar
class User: pass

f1 = type

A = TypeVar('A')
def f2(func: A) -> A:
    return func

u = User()

reveal_type(f1(u))  # E: Revealed type is 'Type[__main__.User]'
reveal_type(f2(type)(u))  # E: Revealed type is 'Type[__main__.User]'
[builtins fixtures/classmethod.pyi]
[out]

[case testTypeConstructorLookalikeFails]
class User: pass

def fake1(a: object) -> type:
    return User
def fake2(a: int) -> type:
    return User

reveal_type(type(User()))  # E: Revealed type is 'Type[__main__.User]'
reveal_type(fake1(User()))  # E: Revealed type is 'builtins.type'
reveal_type(fake2(3))  # E: Revealed type is 'builtins.type'
[builtins fixtures/classmethod.pyi]
[out]

[case testOtherTypeConstructorsSucceed]
def foo(self) -> int: return self.attr

User = type('User', (object,), {'foo': foo, 'attr': 3})
reveal_type(User)  # E: Revealed type is 'builtins.type'
[builtins fixtures/args.pyi]
[out]

[case testTypeTypeComparisonWorks]
class User: pass

User == User
User == type(User())
type(User()) == User
type(User()) == type(User())

User != User
User != type(User())
type(User()) != User
type(User()) != type(User())

int == int
int == type(3)
type(3) == int
type(3) == type(3)

int != int
int != type(3)
type(3) != int
type(3) != type(3)

User is User
User is type(User)
type(User) is User
type(User) is type(User)

int is int
int is type(3)
type(3) is int
type(3) is type(3)

int.__eq__(int)
int.__eq__(3, 4)
[builtins fixtures/args.pyi]
[out]
main:33: error: Too few arguments for "__eq__" of "int"
main:33: error: Unsupported operand types for == ("int" and "int")

[case testMroSetAfterError]
class C(str, str):
    foo = 0
    bar = foo
[out]
main:1: error: Duplicate base class "str"

[case testCannotDetermineMro]
class A: pass
class B(A): pass
class C(B): pass
class D(A, B): pass # E: Cannot determine consistent method resolution order (MRO) for "D"
class E(C, D): pass # E: Cannot determine consistent method resolution order (MRO) for "E"

[case testInconsistentMroLocalRef]
class A: pass
class B(object, A): # E: Cannot determine consistent method resolution order (MRO) for "B"
    def readlines(self): pass
    __iter__ = readlines

[case testDynamicMetaclass]
# flags: --fast-parser
class C(metaclass=int()):  # E: Dynamic metaclass not supported for 'C'
    pass