check-expressions.test

-- Test cases for simple expressions.
--
-- See also:
--  * check-functions.test contains test cases for calls.
--  * check-varargs.test contains test cases for *args.
--  * check-dynamic.test contains test cases related to 'Any' type.
--  * check-generics.test contains test cases for generic values.


-- None expression
-- ---------------


[case testNoneAsRvalue]
import typing
a = None # type: A
class A: pass
[out]

[case testNoneAsArgument]
import typing
def f(x: 'A', y: 'B') -> None: pass
f(None, None)
class A: pass
class B(A): pass
[out]


-- Simple expressions
-- ------------------


[case testIntLiteral]
a = 0
b = None # type: A
if int():
    b = 1 # E: Incompatible types in assignment (expression has type "int", variable has type "A")
if int():
    a = 1
class A:
    pass

[case testStrLiteral]
a = ''
b = None # type: A
if int():
    b = 'x' # E: Incompatible types in assignment (expression has type "str", variable has type "A")
if int():
    a = 'x'
if int():
    a = r"x"
if int():
    a = """foo"""
class A:
    pass

[case testFloatLiteral]
a = 0.0
b = None # type: A
if str():
    b = 1.1 # E: Incompatible types in assignment (expression has type "float", variable has type "A")
if str():
    a = 1.1
class A:
    pass
[builtins fixtures/dict.pyi]

[case testComplexLiteral]
a = 0.0j
b = None # type: A
if str():
    b = 1.1j # E: Incompatible types in assignment (expression has type "complex", variable has type "A")
if str():
    a = 1.1j
class A:
    pass
[builtins fixtures/dict.pyi]

[case testBytesLiteral]
b, a = None, None # type: (bytes, A)
if str():
    b = b'foo'
if str():
    b = br"foo"
if str():
    b = b'''foo'''
if str():
    a = b'foo' # E: Incompatible types in assignment (expression has type "bytes", variable has type "A")
class A: pass
[builtins fixtures/dict.pyi]

[case testUnicodeLiteralInPython3]
s = None  # type: str
if int():
    s = u'foo'
b = None  # type: bytes
if int():
    b = u'foo' # E: Incompatible types in assignment (expression has type "str", variable has type "bytes")
[builtins fixtures/primitives.pyi]


-- Binary operators
-- ----------------


[case testAdd]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a + c  # E: Unsupported operand types for + ("A" and "C")
if int():
    a = a + b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b + a  # E: Unsupported left operand type for + ("B")
if int():
    c = a + b

class A:
    def __add__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testSub]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a - c  # E: Unsupported operand types for - ("A" and "C")
if int():
    a = a - b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b - a  # E: Unsupported left operand type for - ("B")
if int():
    c = a - b

class A:
    def __sub__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testMul]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a * c  # E: Unsupported operand types for * ("A" and "C")
if int():
    a = a * b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b * a  # E: Unsupported left operand type for * ("B")
if int():
    c = a * b

class A:
    def __mul__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testMatMul]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a @ c  # E: Unsupported operand types for @ ("A" and "C")
if int():
    a = a @ b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b @ a  # E: Unsupported left operand type for @ ("B")
if int():
    c = a @ b

class A:
    def __matmul__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testDiv]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a / c  # E: Unsupported operand types for / ("A" and "C")
    a = a / b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b / a  # E: Unsupported left operand type for / ("B")
if int():
    c = a / b

class A:
    def __truediv__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testDivPython2]
# flags: --python-version 2.7
class A(object):
    def __div__(self, other):
        # type: (A, str) -> str
        return 'a'

a = A()
reveal_type(a / 'b')  # N: Revealed type is "builtins.str"
a / 1  # E: Unsupported operand types for / ("A" and "int")
[builtins fixtures/bool.pyi]

[case testDivPython2FutureImport]
# flags: --python-version 2.7
from __future__ import division

class A(object):
    def __truediv__(self, other):
        # type: (A, str) -> str
        return 'a'

a = A()
reveal_type(a / 'b')  # N: Revealed type is "builtins.str"
a / 1  # E: Unsupported operand types for / ("A" and "int")
[builtins fixtures/bool.pyi]

[case testDivPython2FutureImportNotLeaking]
# flags: --python-version 2.7
import m1

[file m1.py]
import m2

class A(object):
    def __div__(self, other):
        # type: (A, str) -> str
        return 'a'

a = A()
reveal_type(a / 'b')  # N: Revealed type is "builtins.str"
a / 1  # E: Unsupported operand types for / ("A" and "int")
[file m2.py]
from __future__ import division
[builtins fixtures/bool.pyi]

[case testDivPython2FutureImportNotLeaking2]
# flags: --python-version 2.7
import m1

[file m1.py]
import m2

class A(object):
    def __div__(self, other):
        # type: (A, str) -> str
        return 'a'

a = A()
reveal_type(a / 'b')  # N: Revealed type is "builtins.str"
a / 1  # E: Unsupported operand types for / ("A" and "int")
[file m2.py]
# empty
[builtins fixtures/bool.pyi]

[case testIntDiv]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a // c  # E: Unsupported operand types for // ("A" and "C")
    a = a // b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b // a  # E: Unsupported left operand type for // ("B")
if int():
    c = a // b

class A:
    def __floordiv__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testMod]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a % c  # E: Unsupported operand types for % ("A" and "C")
if int():
    a = a % b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b % a  # E: Unsupported left operand type for % ("B")
if int():
    c = a % b

class A:
    def __mod__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testPow]
a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a ** c  # E: Unsupported operand types for ** ("A" and "C")
if int():
    a = a ** b  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b ** a  # E: Unsupported left operand type for ** ("B")
if int():
    c = a ** b

class A:
    def __pow__(self, x: 'B') -> 'C':
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]

[case testMiscBinaryOperators]

a, b = None, None # type: (A, B)
b = a & a  # Fail
b = a | b  # Fail
b = a ^ a  # Fail
b = a << b # Fail
b = a >> a # Fail

b = a & b
b = a | a
b = a ^ b
b = a << a
b = a >> b
class A:
  def __and__(self, x: 'B') -> 'B': pass
  def __or__(self, x: 'A') -> 'B': pass
  def __xor__(self, x: 'B') -> 'B': pass
  def __lshift__(self, x: 'A') -> 'B': pass
  def __rshift__(self, x: 'B') -> 'B': pass
class B: pass
[builtins fixtures/tuple.pyi]
[out]
main:3: error: Unsupported operand types for & ("A" and "A")
main:4: error: Unsupported operand types for | ("A" and "B")
main:5: error: Unsupported operand types for ^ ("A" and "A")
main:6: error: Unsupported operand types for << ("A" and "B")
main:7: error: Unsupported operand types for >> ("A" and "A")

[case testBooleanAndOr]
a, b = None, None # type: (A, bool)
if int():
    b = b and b
if int():
    b = b or b
if int():
    b = b and a # E: Incompatible types in assignment (expression has type "Union[Literal[False], A]", variable has type "bool")
if int():
    b = a and b # E: Incompatible types in assignment (expression has type "Union[A, bool]", variable has type "bool")
if int():
    b = b or a  # E: Incompatible types in assignment (expression has type "Union[Literal[True], A]", variable has type "bool")
if int():
    b = a or b  # E: Incompatible types in assignment (expression has type "Union[A, bool]", variable has type "bool")
class A: pass

[builtins fixtures/bool.pyi]

[case testRestrictedTypeAnd]

b = None # type: bool
i = None # type: str
j = not b and i
if j:
    reveal_type(j) # N: Revealed type is "builtins.str"
[builtins fixtures/bool.pyi]

[case testRestrictedTypeOr]

b = None # type: bool
i = None # type: str
j = b or i
if not j:
    reveal_type(j) # N: Revealed type is "builtins.str"
[builtins fixtures/bool.pyi]

[case testAndOr]

s = ""
b = bool()
reveal_type(s and b or b)  # N: Revealed type is "builtins.bool"
[builtins fixtures/bool.pyi]

[case testRestrictedBoolAndOrWithGenerics]
from typing import List

def f(a: List[str], b: bool) -> bool:
    x = a and b
    y: bool
    return reveal_type(x or y)  # N: Revealed type is "builtins.bool"
[builtins fixtures/list.pyi]

[case testNonBooleanOr]
c, d, b = None, None, None # type: (C, D, bool)
if int():
    c = c or c
if int():
    c = c or d
if int():
    c = d or c
if int():
    b = c or c # E: Incompatible types in assignment (expression has type "C", variable has type "bool")
if int():
    d = c or d # E: Incompatible types in assignment (expression has type "C", variable has type "D")
if int():
    d = d or c # E: Incompatible types in assignment (expression has type "C", variable has type "D")
class C: pass
class D(C): pass
[builtins fixtures/bool.pyi]

[case testInOperator]
from typing import Iterator, Iterable, Any
a, b, c, d, e = None, None, None, None, None # type: (A, B, bool, D, Any)
if int():
    c = c in a  # E: Unsupported operand types for in ("bool" and "A")
if int():
    a = b in a  # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    c = a in b  # E: Unsupported right operand type for in ("B")
if int():
    c = b in d  # E: Unsupported operand types for in ("B" and "D")
if int():
    c = b in a
if int():
    c = a in d
if int():
    c = e in d
if int():
    c = a in e

class A:
    def __contains__(self, x: 'B') -> bool: pass
class B: pass
class D(Iterable[A]):
    def __iter__(self) -> Iterator[A]: pass
[builtins fixtures/bool.pyi]

[case testNotInOperator]
from typing import Iterator, Iterable, Any
a, b, c, d, e = None, None, None, None, None # type: (A, B, bool, D, Any)
if int():
    c = c not in a  # E: Unsupported operand types for in ("bool" and "A")
if int():
    a = b not in a  # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    c = a not in b  # E: Unsupported right operand type for in ("B")
if int():
    c = b not in d  # E: Unsupported operand types for in ("B" and "D")
if int():
    c = b not in a
if int():
    c = a not in d
if int():
    c = e in d
if int():
    c = a in e

class A:
    def __contains__(self, x: 'B') -> bool: pass
class B: pass
class D(Iterable[A]):
    def __iter__(self) -> Iterator[A]: pass
[builtins fixtures/bool.pyi]

[case testNonBooleanContainsReturnValue]
a, b, c = None, None, None # type: (A, bool, str)
if int():
    b = a not in a
if int():
    b = a in a
if int():
    c = a not in a  # E: Incompatible types in assignment (expression has type "bool", variable has type "str")
if int():
    c = a in a  # E: Incompatible types in assignment (expression has type "bool", variable has type "str")

class A:
  def __contains__(self, x: 'A') -> str: pass
[builtins fixtures/bool.pyi]

[case testInWithInvalidArgs]
a = 1 in ([1] + ['x'])  # E: List item 0 has incompatible type "str"; expected "int"
[builtins fixtures/list.pyi]

[case testEq]

a, b = None, None # type: (A, bool)
if int():
    a = a == b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    a = a != b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    b = a == b
if int():
    b = a != b

class A:
  def __eq__(self, o: object) -> bool: pass
  def __ne__(self, o: object) -> bool: pass
[builtins fixtures/bool.pyi]

[case testLtAndGt]
a, b, bo = None, None, None # type: (A, B, bool)
if int():
    a = a < b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    a = a > b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    bo = a < b
if int():
    bo = a > b

class A:
    def __lt__(self, o: 'B') -> bool: pass
    def __gt__(self, o: 'B') -> bool: pass
class B:
    def __lt__(self, o: 'B') -> bool: pass
    def __gt__(self, o: 'B') -> bool: pass
[builtins fixtures/bool.pyi]

[case testCmp_python2]

a, b, c, bo = None, None, None, None # type: (A, B, C, bool)
bo = a == a  # E: Unsupported operand types for == ("A" and "A")
bo = a != a  # E: Unsupported operand types for comparison ("A" and "A")
bo = a < b
bo = a > b
bo = b <= b
bo = b <= c
bo = b >= c  # E: Unsupported operand types for comparison ("C" and "B")
bo = a >= b
bo = c >= b
bo = c <= b  # E: Unsupported operand types for comparison ("B" and "C")
bo = a == c
bo = b == c  # E: Unsupported operand types for == ("C" and "B")

class A:
    def __cmp__(self, o):
      # type: ('B') -> bool
      pass
    def __eq__(self, o):
      # type: ('int') -> bool
      pass
class B:
    def __cmp__(self, o):
        # type: ('B') -> bool
        pass
    def __le__(self, o):
        # type: ('C') -> bool
        pass
class C:
    def __cmp__(self, o):
      # type: ('A') -> bool
      pass
    def __eq__(self, o):
      # type: ('int') -> bool
      pass

[builtins_py2 fixtures/bool_py2.pyi]

[case testDiv_python2]
10 / 'no'  # E: Unsupported operand types for / ("int" and "str")
'no' / 10  # E: Unsupported operand types for / ("str" and "int")
[builtins_py2 fixtures/ops.pyi]

[case cmpIgnoredPy3]

a, b, bo = None, None, None # type: (A, B, bool)
bo = a <= b # E: Unsupported left operand type for <= ("A")

class A:
    def __cmp__(self, o: 'B') -> bool: pass
class B:
    pass

[builtins fixtures/bool.pyi]

[case testLeAndGe]
a, b, bo = None, None, None # type: (A, B, bool)
if int():
    a = a <= b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    a = a >= b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    bo = a <= b
if int():
    bo = a >= b

class A:
    def __le__(self, o: 'B') -> bool: pass
    def __ge__(self, o: 'B') -> bool: pass
class B:
    def __le__(self, o: 'B') -> bool: pass
    def __ge__(self, o: 'B') -> bool: pass
[builtins fixtures/bool.pyi]

[case testChainedComp]

a, b, bo = None, None, None # type: (A, B, bool)
a < a < b < b # Fail
a < b < b < b
a < a > a < b # Fail

class A:
    def __lt__(self, o: 'B') -> bool: pass
    def __gt__(self, o: 'B') -> bool: pass
class B:
    def __lt__(self, o: 'B') -> bool: pass
    def __gt__(self, o: 'B') -> bool: pass
[builtins fixtures/bool.pyi]
[out]
main:3: error: Unsupported operand types for < ("A" and "A")
main:5: error: Unsupported operand types for < ("A" and "A")
main:5: error: Unsupported operand types for > ("A" and "A")


[case testChainedCompBoolRes]
a, b, bo = None, None, None # type: (A, B, bool)
if int():
    bo = a < b < b
if int():
    a = a < b < b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")

class A:
    def __lt__(self, o: 'B') -> bool: pass
    def __gt__(self, o: 'B') -> bool: pass
class B:
    def __lt__(self, o: 'B') -> bool: pass
    def __gt__(self, o: 'B') -> bool: pass
[builtins fixtures/bool.pyi]


[case testChainedCompResTyp]
x, y = None, None # type: (X, Y)
a, b, p, bo = None, None, None, None # type: (A, B, P, bool)
if int():
    b = y == y == y
if int():
    bo = y == y == y # E: Incompatible types in assignment (expression has type "B", variable has type "bool")
if int():
    a = x < y
if int():
    a = x < y == y # E: Incompatible types in assignment (expression has type "P", variable has type "A")
if int():
    p = x < y == y

class P:
    pass
class A(P):
    pass
class B(P):
    pass

class X:
    def __lt__(self, o: 'Y') -> A: pass
    def __gt__(self, o: 'Y') -> A: pass
class Y:
    def __lt__(self, o: 'Y') -> A: pass
    def __gt__(self, o: 'Y') -> A: pass
    def __eq__(self, o: 'Y') -> B: pass  # type: ignore
[builtins fixtures/bool.pyi]


[case testIs]
a, b = None, None # type: (A, bool)
if int():
    a = a is b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    b = a is b
if int():
    b = b is a
if int():
    b = a is None
class A: pass
[builtins fixtures/bool.pyi]

[case testIsNot]
a, b = None, None # type: (A, bool)
if int():
    a = a is not b # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    b = a is not b
if int():
    b = b is not a
if int():
    b = a is not None
class A: pass
[builtins fixtures/bool.pyi]

[case testIsRightOperand]

1 is 1()
[builtins fixtures/bool.pyi]
[out]
main:2: error: "int" not callable

[case testReverseBinaryOperator]

class A:
    def __add__(self, x: int) -> int: pass
class B:
    def __radd__(self, x: A) -> str: pass
s = None  # type: str
n = None  # type: int
if int():
    n = A() + 1
if int():
    s = A() + B()
if int():
    n = A() + B() # E: Incompatible types in assignment (expression has type "str", variable has type "int")

[case testReverseBinaryOperator2]
class A:
    def __add__(self, x: 'A') -> object: pass
class B:
    def __radd__(self, x: A) -> str: pass
s = None  # type: str
n = None  # type: int
if int():
    s = A() + B()
    n = A() + B() # E: Incompatible types in assignment (expression has type "str", variable has type "int")

[case testReverseBinaryOperator3]

class N:
    def __add__(self, x: 'N') -> object: pass
class A:
    def __add__(self, x: N) -> int: pass
class B:
    def __radd__(self, x: N) -> str: pass
s = None  # type: str
s = A() + B() # E: Unsupported operand types for + ("A" and "B")

[case testBinaryOperatorWithAnyRightOperand]
from typing import Any, cast
class A: pass
A() + cast(Any, 1)

[case testReverseComparisonOperator]
class C:
    def __gt__(self, x: 'A') -> object: pass
class A:
    def __lt__(self, x: C) -> int: pass  # E: Signatures of "__lt__" of "A" and "__gt__" of "C" are unsafely overlapping
class B:
    def __gt__(self, x: A) -> str: pass
s = None  # type: str
n = None  # type: int
if int():
    n = A() < C()
    s = A() < B()
if int():
    n = A() < B() # E: Incompatible types in assignment (expression has type "str", variable has type "int")
    s = object() < B() # E: Unsupported operand types for > ("B" and "object")

[case testReversibleComparisonWithExtraArgument]
class C:
    def __lt__(self, o: object, x: str = "") -> int: ...

[case testErrorContextAndBinaryOperators]
import typing
class A:
    def __getitem__(self, i: str) -> int: pass
def f() -> None:
    A()[1] # Error
class B:
    A()[1] # Error
A()[1] # Error
[out]
main:5: error: Invalid index type "int" for "A"; expected type "str"
main:7: error: Invalid index type "int" for "A"; expected type "str"
main:8: error: Invalid index type "int" for "A"; expected type "str"

[case testErrorContextAndBinaryOperators2]
import m
[file m.py]
import typing
class A:
    def __getitem__(self, i: str) -> int: pass
def f() -> None:
    A()[1] # Error
class B:
    A()[1] # Error
A()[1] # Error
[out]
tmp/m.py:5: error: Invalid index type "int" for "A"; expected type "str"
tmp/m.py:7: error: Invalid index type "int" for "A"; expected type "str"
tmp/m.py:8: error: Invalid index type "int" for "A"; expected type "str"


[case testDivmod]
from typing import Tuple, Union, SupportsInt
_Decimal = Union[Decimal, int]
class Decimal(SupportsInt):
    def __init__(self, int) -> None: ...
    def __divmod__(self, other: _Decimal) -> Tuple[Decimal, Decimal]: ...
    def __rdivmod__(self, other: _Decimal) -> Tuple[Decimal, Decimal]: ...

i = 8
f = 8.0
d = Decimal(8)

reveal_type(divmod(i, i))  # N: Revealed type is "Tuple[builtins.int, builtins.int]"
reveal_type(divmod(f, i))  # N: Revealed type is "Tuple[builtins.float, builtins.float]"
reveal_type(divmod(d, i))  # N: Revealed type is "Tuple[__main__.Decimal, __main__.Decimal]"

reveal_type(divmod(i, f))  # N: Revealed type is "Tuple[builtins.float, builtins.float]"
reveal_type(divmod(f, f))  # N: Revealed type is "Tuple[builtins.float, builtins.float]"
divmod(d, f)  # E: Unsupported operand types for divmod ("Decimal" and "float")

reveal_type(divmod(i, d))  # N: Revealed type is "Tuple[__main__.Decimal, __main__.Decimal]"
divmod(f, d)  # E: Unsupported operand types for divmod ("float" and "Decimal")
reveal_type(divmod(d, d))  # N: Revealed type is "Tuple[__main__.Decimal, __main__.Decimal]"

# Now some bad calls
divmod()  # E: "divmod" expects 2 arguments \
          # E: Missing positional arguments "_x", "_y" in call to "divmod"
divmod(7)  # E: "divmod" expects 2 arguments \
           # E: Missing positional argument "_y" in call to "divmod"
divmod(7, 8, 9)  # E: "divmod" expects 2 arguments \
                 # E: Too many arguments for "divmod"
divmod(_x=7, _y=9)  # E: "divmod" must be called with 2 positional arguments

divmod('foo', 'foo')  # E: Unsupported left operand type for divmod ("str")
divmod(i, 'foo')  # E: Unsupported operand types for divmod ("int" and "str")
divmod(f, 'foo')  # E: Unsupported operand types for divmod ("float" and "str")
divmod(d, 'foo')  # E: Unsupported operand types for divmod ("Decimal" and "str")

divmod('foo', i)  # E: Unsupported operand types for divmod ("str" and "int")
divmod('foo', f)  # E: Unsupported operand types for divmod ("str" and "float")
divmod('foo', d)  # E: Unsupported operand types for divmod ("str" and "Decimal")

[builtins fixtures/divmod.pyi]
[typing fixtures/typing-medium.pyi]


-- Unary operators
-- ---------------


[case testUnaryMinus]

a, b = None, None # type: (A, B)
if int():
    a = -a   # E: Incompatible types in assignment (expression has type "B", variable has type "A")
if int():
    b = -b   # E: Unsupported operand type for unary - ("B")
if int():
    b = -a

class A:
    def __neg__(self) -> 'B':
        pass
class B:
    pass
[builtins fixtures/tuple.pyi]

[case testUnaryPlus]
a, b = None, None # type: (A, B)
if int():
    a = +a   # E: Incompatible types in assignment (expression has type "B", variable has type "A")
if int():
    b = +b   # E: Unsupported operand type for unary + ("B")
if int():
    b = +a

class A:
    def __pos__(self) -> 'B':
        pass
class B:
    pass
[builtins fixtures/tuple.pyi]

[case testUnaryNot]
a, b = None, None # type: (A, bool)
if int():
    a = not b  # E: Incompatible types in assignment (expression has type "bool", variable has type "A")
if int():
    b = not a
if int():
    b = not b
class A:
    pass
[builtins fixtures/bool.pyi]

[case testUnaryBitwiseNeg]
a, b = None, None # type: (A, B)
if int():
    a = ~a   # E: Incompatible types in assignment (expression has type "B", variable has type "A")
if int():
    b = ~b   # E: Unsupported operand type for ~ ("B")
if int():
    b = ~a

class A:
    def __invert__(self) -> 'B':
        pass
class B:
    pass


-- Indexing
-- --------
[builtins fixtures/tuple.pyi]


[case testIndexing]

a, b, c = None, None, None # type: (A, B, C)
if int():
    c = a[c]  # E: Invalid index type "C" for "A"; expected type "B"
if int():
    a = a[b]  # E: Incompatible types in assignment (expression has type "C", variable has type "A")
if int():
    c = b[a]  # E: Value of type "B" is not indexable
if int():
    c = a[b]

class A:
    def __getitem__(self, x: 'B') -> 'C':
        pass
class B: pass
class C: pass
[builtins fixtures/tuple.pyi]

[case testIndexingAsLvalue]

a, b, c = None, None, None # type: (A, B, C)
a[c] = c  # Fail
a[b] = a  # Fail
b[a] = c  # Fail
a[b] = c

class A:
    def __setitem__(self, x: 'B', y: 'C') -> None:
        pass
class B:
    pass
class C:
    pass
[builtins fixtures/tuple.pyi]
[out]
main:3: error: Invalid index type "C" for "A"; expected type "B"
main:4: error: Incompatible types in assignment (expression has type "A", target has type "C")
main:5: error: Unsupported target for indexed assignment ("B")

[case testOverloadedIndexing]
from foo import *
[file foo.pyi]
from typing import overload

a, b, c = None, None, None  # type: (A, B, C)
a[b]
a[c]
a[1]  # E: No overload variant of "__getitem__" of "A" matches argument type "int" \
      # N: Possible overload variants: \
      # N:     def __getitem__(self, B) -> int \
      # N:     def __getitem__(self, C) -> str

i, s = None, None  # type: (int, str)
if int():
    i = a[b]
if int():
    s = a[b]  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
if int():
    i = a[c]  # E: Incompatible types in assignment (expression has type "str", variable has type "int")
if int():
    s = a[c]

class A:
    @overload
    def __getitem__(self, x: 'B') -> int:
        pass
    @overload
    def __getitem__(self, x: 'C') -> str:
        pass
class B: pass
class C: pass
[builtins fixtures/tuple.pyi]
[out]


-- Cast expression
-- ---------------


[case testCastExpressions]
from typing import cast, Any
class A: pass
class B: pass
class C(A): pass
a, b, c = None, None, None # type: (A, B, C)

if int():
    a = cast(A, a())       # E: "A" not callable
if int():
    a = cast(Any, a())     # E: "A" not callable
    b = cast(A, a)         # E: Incompatible types in assignment (expression has type "A", variable has type "B")

if int():
    a = cast(A, b)
if int():
    a = cast(A, a)
    c = cast(C, a)
if int():
    a = cast(A, c)
if int():
    a = cast(Any, b)
    b = cast(Any, a)
[builtins fixtures/tuple.pyi]
[out]

[case testAnyCast]
from typing import cast, Any
a, b = None, None # type: (A, B)
a = cast(Any, a())     # Fail
a = cast(Any, b)
b = cast(Any, a)
class A: pass
class B: pass
[builtins fixtures/tuple.pyi]
[out]
main:3: error: "A" not callable


-- None return type
-- ----------------


[case testNoneReturnTypeBasics]
a, o = None, None # type: (A, object)
if int():
    a = f()         # E: "f" does not return a value
if int():
    o = a()         # E: Function does not return a value
if int():
    o = A().g(a)    # E: "g" of "A" does not return a value
if int():
    o = A.g(a, a)   # E: "g" of "A" does not return a value
A().g(f())      # E: "f" does not return a value
x: A = f()      # E: "f" does not return a value
f()
A().g(a)

def f() -> None:
    pass

class A:
    def g(self, x: object) -> None:
        pass
    def __call__(self) -> None:
        pass
[builtins fixtures/tuple.pyi]

[case testNoneReturnTypeWithStatements]
import typing
if f():   # Fail
    pass
elif f(): # Fail
    pass
while f(): # Fail
    pass
def g() -> object:
    return f() # Fail
raise f() # Fail

def f() -> None: pass
[builtins fixtures/exception.pyi]
[out]
main:2: error: "f" does not return a value
main:4: error: "f" does not return a value
main:6: error: "f" does not return a value
main:9: error: "f" does not return a value
main:10: error: "f" does not return a value

[case testNoneReturnTypeWithExpressions]
from typing import cast
a = None # type: A
[f()]       # E: "f" does not return a value
f() + a     # E: "f" does not return a value
a + f()     # E: "f" does not return a value
f() == a    # E: "f" does not return a value
a != f()    # E: "f" does not return a value
cast(A, f())
f().foo     # E: "f" does not return a value

def f() -> None: pass
class A:
    def __add__(self, x: 'A') -> 'A': pass
[builtins fixtures/list.pyi]

[case testNoneReturnTypeWithExpressions2]
import typing

a, b = None, None # type: (A, bool)
f() in a   # E: "f" does not return a value  # E: Unsupported right operand type for in ("A")
a < f()    # E: "f" does not return a value
f() <= a   # E: "f" does not return a value
a in f()   # E: "f" does not return a value
-f()       # E: "f" does not return a value
not f()    # E: "f" does not return a value
f() and b  # E: "f" does not return a value
b or f()   # E: "f" does not return a value

def f() -> None: pass
class A:
    def __add__(self, x: 'A') -> 'A':
        pass
[builtins fixtures/bool.pyi]


-- Slicing
-- -------


[case testGetSlice]
a, b = None, None # type: (A, B)
if int():
    a = a[1:2] # E: Incompatible types in assignment (expression has type "B", variable has type "A")
if int():
    a = a[1:]  # E: Incompatible types in assignment (expression has type "B", variable has type "A")
if int():
    a = a[:2]  # E: Incompatible types in assignment (expression has type "B", variable has type "A")
if int():
    a = a[:]   # E: Incompatible types in assignment (expression has type "B", variable has type "A")

if int():
    b = a[1:2]
if int():
    b = a[1:]
if int():
    b = a[:2]
if int():
    b = a[:]

class A:
  def __getitem__(self, s: slice) -> 'B': pass
class B: pass
[builtins fixtures/slice.pyi]

[case testSlicingWithInvalidBase]

a = None # type: A
a[1:2] # E: Invalid index type "slice" for "A"; expected type "int"
a[:]   # E: Invalid index type "slice" for "A"; expected type "int"
class A:
  def __getitem__(self, n: int) -> 'A': pass
[builtins fixtures/slice.pyi]

[case testSlicingWithNonindexable]

o = None # type: object
o[1:2] # E: Value of type "object" is not indexable
o[:]   # E: Value of type "object" is not indexable
[builtins fixtures/slice.pyi]

[case testNonIntSliceBounds]
from typing import Any
a, o = None, None # type: (Any, object)
a[o:1] # E: Slice index must be an integer or None
a[1:o] # E: Slice index must be an integer or None
a[o:]  # E: Slice index must be an integer or None
a[:o]  # E: Slice index must be an integer or None
[builtins fixtures/slice.pyi]

[case testNoneSliceBounds]
from typing import Any
a = None # type: Any
a[None:1]
a[1:None]
a[None:]
a[:None]
[builtins fixtures/slice.pyi]

[case testNoneSliceBoundsWithStrictOptional]
# flags: --strict-optional
from typing import Any
a = None # type: Any
a[None:1]
a[1:None]
a[None:]
a[:None]
[builtins fixtures/slice.pyi]


-- Lambdas
-- -------


[case testTrivialLambda]
from typing import Callable
f = lambda: 1 # type: Callable[[], int]
if int():
    f = lambda: ''.x # E: "str" has no attribute "x"
if int():
    f = lambda: '' \
        # E: Incompatible types in assignment (expression has type "Callable[[], str]", variable has type "Callable[[], int]") \
        # E: Incompatible return value type (got "str", expected "int")

[case testVoidLambda]
import typing
def void() -> None:
    pass
x = lambda: void() # type: typing.Callable[[], None]

[case testNoCrashOnLambdaGenerator]
from typing import Iterator, Callable

# These should not crash
lambda: (yield)

gen: Callable[[], Iterator[str]]
gen = (lambda: (yield 1))  # E: Incompatible types in "yield" (actual type "int", expected type "str")

def fun(cb: Callable[[], Iterator[str]]) -> None:
    pass
fun(lambda: (yield from [1]))  # E: Incompatible types in "yield from" (actual type "int", expected type "str")
[builtins fixtures/list.pyi]
[out]

[case testLambdaAndReachability]
def f() -> None:
    aa = []
    y = lambda x: 1
    aa.append(1)
    1()  # E: "int" not callable
[builtins fixtures/list.pyi]


-- List comprehensions
-- -------------------


[case testSimpleListComprehension]
from typing import List
a = None # type: List[A]
a = [x for x in a]
b = [x for x in a] # type: List[B] # E: List comprehension has incompatible type List[A]; expected List[B]
class A: pass
class B: pass
[builtins fixtures/for.pyi]

[case testSimpleListComprehensionNestedTuples]
from typing import List, Tuple
l = None # type: List[Tuple[A, Tuple[A, B]]]
a = [a2 for a1, (a2, b1) in l] # type: List[A]
b = [a2 for a1, (a2, b1) in l] # type: List[B] # E: List comprehension has incompatible type List[A]; expected List[B]
class A: pass
class B: pass
[builtins fixtures/for.pyi]

[case testSimpleListComprehensionNestedTuples2]
from typing import List, Tuple
l = None # type: List[Tuple[int, Tuple[int, str]]]
a = [f(d) for d, (i, s) in l]
b = [f(s) for d, (i, s) in l] # E: Argument 1 to "f" has incompatible type "str"; expected "int"

def f(x: int): pass
[builtins fixtures/for.pyi]

[case testListComprehensionWithNonDirectMapping]
from typing import List
a: List[A]
b: List[B]
if int():
    b = [f(x) for x in a]
if int():
    a = [f(x) for x in a] # E: List comprehension has incompatible type List[B]; expected List[A]
([f(x) for x in b])   # E: Argument 1 to "f" has incompatible type "B"; expected "A"
class A: pass
class B: pass
def f(a: A) -> B: pass
[builtins fixtures/for.pyi]

[case testErrorInListComprehensionCondition]
from typing import List
a = None # type: List[A]
a = [x for x in a if x()] # E: "A" not callable
class A: pass
[builtins fixtures/for.pyi]

[case testTypeInferenceOfListComprehension]
from typing import List
a = None # type: List[A]
o = [x for x in a] # type: List[object]
class A: pass
[builtins fixtures/for.pyi]

[case testSimpleListComprehensionInClassBody]
from typing import List
class A:
    a = None # type: List[A]
    a = [x for x in a]
    b = [x for x in a] # type: List[B] # E: List comprehension has incompatible type List[A]; expected List[B]
class B: pass
[builtins fixtures/for.pyi]
[out]


-- Set comprehension
-- -----------------


[case testSimpleSetComprehension]
from typing import Set
a = None # type: Set[A]
a = {x for x in a}
b = {x for x in a} # type: Set[B] # E: Set comprehension has incompatible type Set[A]; expected Set[B]
class A: pass
class B: pass
[builtins fixtures/set.pyi]


-- Dictionary comprehension
-- ------------------------


[case testSimpleDictionaryComprehension]
from typing import Dict, List, Tuple
abd = None # type: Dict[A, B]
abl = None # type: List[Tuple[A, B]]
abd = {a: b for a, b in abl}
x = {a: b for a, b in abl} # type: Dict[B, A]
y = {a: b for a, b in abl} # type: A
class A: pass
class B: pass
[builtins fixtures/dict.pyi]
[out]
main:5: error: Key expression in dictionary comprehension has incompatible type "A"; expected type "B"
main:5: error: Value expression in dictionary comprehension has incompatible type "B"; expected type "A"
main:6: error: Incompatible types in assignment (expression has type "Dict[A, B]", variable has type "A")


[case testDictionaryComprehensionWithNonDirectMapping]
from typing import Dict, List, Tuple
abd: Dict[A, B]
abl = None # type: List[Tuple[A, B]]
abd = {a: f(b) for a, b in abl}
class A: pass
class B: pass
class C: pass
def f(b: A) -> C: pass
[builtins fixtures/dict.pyi]
[out]
main:4: error: Value expression in dictionary comprehension has incompatible type "C"; expected type "B"
main:4: error: Argument 1 to "f" has incompatible type "B"; expected "A"


-- Generator expressions
-- ---------------------


[case testSimpleGeneratorExpression]
from typing import Iterator
# The implementation is mostly identical to list comprehensions, so only a few
# test cases is ok.
a = None # type: Iterator[int]
if int():
    a = (x for x in a)
b = None # type: Iterator[str]
if int():
    b = (x for x in a) # E: Generator has incompatible item type "int"; expected "str"
[builtins fixtures/for.pyi]

[case testGeneratorIncompatibleErrorMessage]
from typing import Callable, Iterator, List

a = []  # type: List[Callable[[], str]]
b = None  # type: Iterator[Callable[[], int]]
if int():
    b = (x for x in a)  # E: Generator has incompatible item type "Callable[[], str]"; expected "Callable[[], int]"
[builtins fixtures/list.pyi]

-- Conditional expressions
-- -----------------------


[case testSimpleConditionalExpression]
import typing
y = ''
x = 1 if y else 2
if int():
    x = 3
if int():
    x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "int")

[case testConditionalExpressionWithEmptyCondition]
import typing
def f() -> None: pass
x = 1 if f() else 2 # E: "f" does not return a value

[case testConditionalExpressionWithSubtyping]
import typing
class A: pass
class B(A): pass
x = B() if bool() else A()
if int():
    x = A()
if int():
    x = '' # E: Incompatible types in assignment (expression has type "str", variable has type "A")
y = A() if bool() else B()
if int():
    y = A()
if int():
    y = '' # E: Incompatible types in assignment (expression has type "str", variable has type "A")
[builtins fixtures/bool.pyi]

[case testConditionalExpressionAndTypeContext]
import typing
x = [1] if bool() else []
if int():
    x = [1]
if int():
    x = ['x'] # E: List item 0 has incompatible type "str"; expected "int"
[builtins fixtures/list.pyi]

[case testConditionalExpressionUnion]
from typing import Union
reveal_type(1 if bool() else 2) # N: Revealed type is "builtins.int"
reveal_type(1 if bool() else '') # N: Revealed type is "builtins.object"
x: Union[int, str] = reveal_type(1 if bool() else '') \
    # N: Revealed type is "Union[Literal[1]?, Literal['']?]"
class A:
    pass
class B(A):
    pass
class C:
    pass
class D(A):
    pass
a = A()
b = B()
c = C()
d = D()
reveal_type(a if bool() else b) # N: Revealed type is "__main__.A"
reveal_type(b if bool() else c) # N: Revealed type is "builtins.object"
reveal_type(c if bool() else b) # N: Revealed type is "builtins.object"
reveal_type(c if bool() else a) # N: Revealed type is "builtins.object"
reveal_type(d if bool() else b) # N: Revealed type is "__main__.A"
[builtins fixtures/bool.pyi]

[case testConditionalExpressionUnionWithAny]
from typing import Union, Any
a: Any
x: Union[int, str] = reveal_type(a if int() else 1)  # N: Revealed type is "Union[Any, Literal[1]?]"
reveal_type(a if int() else 1)  # N: Revealed type is "Any"

[case testConditionalExpressionStatementNoReturn]
from typing import List, Union
x = []
y = ""
x.append(y) if bool() else x.append(y)
z = x.append(y) if bool() else x.append(y) # E: "append" of "list" does not return a value
[builtins fixtures/list.pyi]

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


[case testOperationsWithNonInstanceTypes]
from typing import cast
class A:
    def __add__(self, a: 'A') -> 'A': pass
a = None # type: A
None + a   # Fail
f + a      # Fail
a + f      # Fail
cast(A, f)

def f() -> None:
    pass
[out]
main:5: error: Unsupported left operand type for + ("None")
main:6: error: Unsupported left operand type for + ("Callable[[], None]")
main:7: error: Unsupported operand types for + ("A" and "Callable[[], None]")

[case testOperatorMethodWithInvalidArgCount]

a = None # type: A
a + a  # Fail

class A:
    def __add__(self) -> 'A':
        pass
[out]
main:3: error: Too many arguments for "__add__" of "A"

[case testOperatorMethodAsVar]
from typing import Any
class A:
    def __init__(self, _add: Any) -> None:
        self.__add__ = _add
a = None # type: A
a + a
[out]

[case testOperatorMethodAsVar2]

class A:
    def f(self, x: int) -> str: pass
    __add__ = f
s = None  # type: str
s = A() + 1
A() + (A() + 1)
[out]
main:7: error: Argument 1 has incompatible type "str"; expected "int"

[case testIndexedLvalueWithSubtypes]

a, b, c = None, None, None # type: (A, B, C)
a[c] = c
a[b] = c
a[c] = b

class A:
    def __setitem__(self, x: 'B', y: 'B') -> None:
        pass
class B:
    pass
class C(B):
    pass
[builtins fixtures/tuple.pyi]
[out]


-- Ellipsis
-- --------


[case testEllipsis]

a = None # type: A
if str():
    a = ...  # E: Incompatible types in assignment (expression has type "ellipsis", variable has type "A")
b = ...
c = ...
if str():
    b = c
....__class__
....a  # E: "ellipsis" has no attribute "a"

class A: pass
[builtins fixtures/dict.pyi]
[out]


-- Yield expression
-- ----------------


[case testYieldExpression]
def f(x: int) -> None:
    x = yield f('')
    x = 1
[builtins fixtures/for.pyi]
[out]
main:1: error: The return type of a generator function should be "Generator" or one of its supertypes
main:2: error: "f" does not return a value
main:2: error: Argument 1 to "f" has incompatible type "str"; expected "int"

[case testYieldExpressionWithNone]
from typing import Iterator
def f(x: int) -> Iterator[None]:
    (yield)
[builtins fixtures/for.pyi]
[out]


-- Yield from expression
-- ----------------


[case testYieldFromIteratorHasNoValue]
from typing import Iterator
def f() -> Iterator[int]:
    yield 5
def g() -> Iterator[int]:
    a = yield from f()  # E: Function does not return a value

[case testYieldFromGeneratorHasValue]
from typing import Iterator, Generator
def f() -> Generator[int, None, str]:
    yield 5
    return "ham"
def g() -> Iterator[int]:
    a = "string"
    a = yield from f()
[out]

[case testYieldFromTupleExpression]
from typing import Generator
def g() -> Generator[int, None, None]:
    x = yield from ()  # E: Function does not return a value
    x = yield from (0, 1, 2)  # E: Function does not return a value
    x = yield from (0, "ERROR")  # E: Incompatible types in "yield from" (actual type "object", expected type "int") \
                                 # E: Function does not return a value
    x = yield from ("ERROR",)  # E: Incompatible types in "yield from" (actual type "str", expected type "int") \
                               # E: Function does not return a value
[builtins fixtures/tuple.pyi]

-- dict(...)
-- ---------


-- Note that the stub used in unit tests does not have all overload
-- variants, but it should not matter.

[case testDictWithKeywordArgsOnly]
from typing import Dict, Any
d1 = dict(a=1, b=2) # type: Dict[str, int]
d2 = dict(a=1, b='') # type: Dict[str, int] # E: Dict entry 1 has incompatible type "str": "str"; expected "str": "int"
d3 = dict(a=1) # type: Dict[int, int] # E: Dict entry 0 has incompatible type "str": "int"; expected "int": "int"
d4 = dict(a=1, b=1)
d4.xyz # E: "Dict[str, int]" has no attribute "xyz"
d5 = dict(a=1, b='') # type: Dict[str, Any]
[builtins fixtures/dict.pyi]

[case testDictWithoutKeywordArgs]
from typing import Dict
d = dict() # E: Need type annotation for "d" (hint: "d: Dict[<type>, <type>] = ...")
d2 = dict() # type: Dict[int, str]
dict(undefined) # E: Name "undefined" is not defined
[builtins fixtures/dict.pyi]

[case testDictFromList]
from typing import Dict
d = dict([(1, 'x'), (2, 'y')])
d() # E: "Dict[int, str]" not callable
d2 = dict([(1, 'x')]) # type: Dict[str, str] # E: List item 0 has incompatible type "Tuple[int, str]"; expected "Tuple[str, str]"
[builtins fixtures/dict.pyi]

[case testDictFromIterableAndKeywordArg]
from typing import Dict
it = [('x', 1)]

d = dict(it, x=1)
d() # E: "Dict[str, int]" not callable

d2 = dict(it, x='')
d2() # E: "Dict[str, object]" not callable

d3 = dict(it, x='') # type: Dict[str, int] # E: Argument "x" to "dict" has incompatible type "str"; expected "int"
[builtins fixtures/dict.pyi]

[case testDictFromIterableAndKeywordArg2]
it = [(1, 'x')]
dict(it, x='y') # E: Keyword argument only valid with "str" key type in call to "dict"
[builtins fixtures/dict.pyi]

[case testDictFromIterableAndKeywordArg3]
d = dict([], x=1)
d() # E: "Dict[str, int]" not callable
[builtins fixtures/dict.pyi]

[case testDictFromIterableAndStarStarArgs]
from typing import Dict
it = [('x', 1)]

kw = {'x': 1}
d = dict(it, **kw)
d() # E: "Dict[str, int]" not callable

kw2 = {'x': ''}
d2 = dict(it, **kw2)
d2() # E: "Dict[str, object]" not callable

d3 = dict(it, **kw2) # type: Dict[str, int] # E: Argument 2 to "dict" has incompatible type "**Dict[str, str]"; expected "int"
[builtins fixtures/dict.pyi]

[case testDictFromIterableAndStarStarArgs2]
it = [(1, 'x')]
kw = {'x': 'y'}
d = dict(it, **kw) # E: Keyword argument only valid with "str" key type in call to "dict"
d() # E: "Dict[int, str]" not callable
[builtins fixtures/dict.pyi]

[case testUserDefinedClassNamedDict]
from typing import Generic, TypeVar
T = TypeVar('T')
S = TypeVar('S')
class dict(Generic[T, S]):
    def __init__(self, x: T, **kwargs: T) -> None: pass
dict(1, y=1)
[builtins fixtures/dict.pyi]

[case testSpecialSignatureForSubclassOfDict]
from typing import TypeVar, Dict, Generic
T = TypeVar('T')
S = TypeVar('S')
class D1(dict): pass # Implicit base class Dict[Any, Any]
D1([(1, 2)], x=1)
class D2(Dict[T, S], Generic[T, S]): pass
da = D2([('x', 2)], x=1)
da() # E: "D2[str, int]" not callable
D2([(1, 2)], x=1) # E: Keyword argument only valid with "str" key type in call to "dict"
db = D2(x=1)
db() # E: "D2[str, int]" not callable
[builtins fixtures/dict.pyi]

[case testSpecialSignatureForSubclassOfDict2]
from typing import TypeVar, Dict, Generic
T = TypeVar('T')
class D(Dict[str, T], Generic[T]): pass
D([('x', 1)], x=1)
[builtins fixtures/dict.pyi]

[case testOverridingSpecialSignatureInSubclassOfDict]
from typing import TypeVar, Dict, Generic
T = TypeVar('T')
S = TypeVar('S')
class D(Dict[T, S], Generic[T, S]):
    def __init__(self, x: S, y: T) -> None: pass
d = D(1, y='')
d() # E: "D[str, int]" not callable
[builtins fixtures/dict.pyi]

[case testRevealType]
reveal_type(1) # N: Revealed type is "Literal[1]?"

[case testRevealLocals]
x = 1
y = 2
z = x + y
reveal_locals()
[out]
main:4: note: Revealed local types are:
main:4: note:     x: builtins.int
main:4: note:     y: builtins.int
main:4: note:     z: builtins.int

[case testUndefinedRevealType]
reveal_type(x)
[out]
main:1: error: Name "x" is not defined
main:1: note: Revealed type is "Any"

[case testUserDefinedRevealType]
def reveal_type(x: int) -> None: pass
reveal_type("foo") # E: Argument 1 to "reveal_type" has incompatible type "str"; expected "int"

[case testTypingRevealType]
from typing import reveal_type
from typing import reveal_type as show_me_the_type

reveal_type(1) # N: Revealed type is "Literal[1]?"
show_me_the_type(1) # N: Revealed type is "Literal[1]?"

[case testTypingExtensionsRevealType]
from typing_extensions import reveal_type
from typing_extensions import reveal_type as show_me_the_type

reveal_type(1) # N: Revealed type is "Literal[1]?"
show_me_the_type(1) # N: Revealed type is "Literal[1]?"

[builtins fixtures/tuple.pyi]

[case testRevealTypeVar]
reveal_type = 1
1 + "foo" # E: Unsupported operand types for + ("int" and "str")

[case testRevealForward]
def f() -> None:
    reveal_type(x)
x = 1 + 1
[out]
main:2: note: Revealed type is "builtins.int"

[case testRevealUncheckedFunction]
def f():
    x = 42
    reveal_type(x)
[out]
main:3: note: Revealed type is "Any"
main:3: note: 'reveal_type' always outputs 'Any' in unchecked functions

[case testRevealCheckUntypedDefs]
# flags: --check-untyped-defs
def f():
    x = 42
    reveal_type(x)
[out]
main:4: note: Revealed type is "builtins.int"

[case testRevealTypedDef]
def f() -> None:
    x = 42
    reveal_type(x)
[out]
main:3: note: Revealed type is "builtins.int"

[case testLambdaTypedContext]
def f() -> None:
    lambda: 'a'.missing()  # E: "str" has no attribute "missing"

[case testLambdaUnypedContext]
def f():
    lambda: 'a'.missing()

[case testLambdaCheckUnypedContext]
# flags: --check-untyped-defs
def f():
    lambda: 'a'.missing()  # E: "str" has no attribute "missing"

[case testEqNone]
None == None
[builtins fixtures/ops.pyi]

[case testLtNone]
None < None  # E: Unsupported left operand type for < ("None")
[builtins fixtures/ops.pyi]

[case testDictWithStarExpr]

b = {'z': 26, *a}  # E: invalid syntax
[builtins fixtures/dict.pyi]

[case testDictWithStarStarExpr]

from typing import Dict
a = {'a': 1}
b = {'z': 26, **a}
c = {**b}
d = {**a, **b, 'c': 3}
e = {1: 'a', **a}  # E: Argument 1 to "update" of "dict" has incompatible type "Dict[str, int]"; expected "Mapping[int, str]"
f = {**b}  # type: Dict[int, int]  # E: List item 0 has incompatible type "Dict[str, int]"; expected "Mapping[int, int]"
[builtins fixtures/dict.pyi]
[typing fixtures/typing-medium.pyi]

[case testDictIncompatibleTypeErrorMessage]
from typing import Dict, Callable

def things() -> int:
    return 42

stuff: Dict[int, Callable[[], str]] = {
    1: things  # E: Dict entry 0 has incompatible type "int": "Callable[[], int]"; expected "int": "Callable[[], str]"
}
[builtins fixtures/dict.pyi]

[case testDictIncompatibleKeyVerbosity]
from typing import Dict
import mod

class A: ...
class B(A): ...

d: Dict[A, B] = {A(): mod.B()}  # E: Dict entry 0 has incompatible type "A": "mod.B"; expected "A": "__main__.B"

[file mod.py]
class B: ...

[builtins fixtures/dict.pyi]

[case testDictIncompatibleValueVerbosity]
from typing import Dict
import mod

class A: ...
class B(A): ...

d: Dict[B, A] = {mod.B(): A()}  # E: Dict entry 0 has incompatible type "mod.B": "A"; expected "__main__.B": "A"

[file mod.py]
class B: ...

[builtins fixtures/dict.pyi]

[case testTypeAnnotationNeededMultipleAssignment]
x, y = [], [] # E: Need type annotation for "x" (hint: "x: List[<type>] = ...") \
            # E: Need type annotation for "y" (hint: "y: List[<type>] = ...")
[builtins fixtures/list.pyi]

[case testStrictEqualityEq]
# flags: --strict-equality
class A: ...
class B: ...
class C(B): ...

A() == B()  # E: Non-overlapping equality check (left operand type: "A", right operand type: "B")
B() == C()
C() == B()
A() != B()  # E: Non-overlapping equality check (left operand type: "A", right operand type: "B")
B() != C()
C() != B()
[builtins fixtures/bool.pyi]

[case testStrictEqualityIs]
# flags: --strict-equality
class A: ...
class B: ...
class C(B): ...

A() is B()  # E: Non-overlapping identity check (left operand type: "A", right operand type: "B")
B() is C()
C() is B()
A() is not B()  # E: Non-overlapping identity check (left operand type: "A", right operand type: "B")
B() is not C()
C() is not B()
[builtins fixtures/bool.pyi]

[case testStrictEqualityContains]
# flags: --strict-equality
class A: ...
class B: ...
class C(B): ...

A() in [B()]  # E: Non-overlapping container check (element type: "A", container item type: "B")
B() in [C()]
C() in [B()]
A() not in [B()]  # E: Non-overlapping container check (element type: "A", container item type: "B")
B() not in [C()]
C() not in [B()]
[builtins fixtures/list.pyi]
[typing fixtures/typing-full.pyi]

[case testStrictEqualityUnions]
# flags: --strict-equality
from typing import Container, Union

class A: ...
class B: ...

a: Union[int, str]
b: Union[A, B]

a == int()
b == int()  # E: Non-overlapping equality check (left operand type: "Union[A, B]", right operand type: "int")

a is int()
b is int()  # E: Non-overlapping identity check (left operand type: "Union[A, B]", right operand type: "int")

ca: Union[Container[int], Container[str]]
cb: Union[Container[A], Container[B]]

42 in ca
42 in cb  # E: Non-overlapping container check (element type: "int", container item type: "Union[A, B]")
[builtins fixtures/bool.pyi]
[typing fixtures/typing-full.pyi]

[case testStrictEqualityBytesSpecial]
# flags: --strict-equality
b'abc' in b'abcde'
[builtins fixtures/primitives.pyi]
[typing fixtures/typing-medium.pyi]

[case testStrictEqualityBytesSpecialUnion]
# flags: --strict-equality
from typing import Union
x: Union[bytes, str]

b'abc' in x
x in b'abc'
[builtins fixtures/primitives.pyi]
[typing fixtures/typing-medium.pyi]

[case testStrictEqualityByteArraySpecial]
# flags: --strict-equality
b'abc' in bytearray(b'abcde')
bytearray(b'abc') in b'abcde'  # OK on Python 3
[builtins fixtures/primitives.pyi]
[typing fixtures/typing-medium.pyi]

[case testBytesVsByteArray_python2]
# flags: --strict-equality --py2
b'hi' in bytearray(b'hi')
[builtins_py2 fixtures/python2.pyi]
[typing fixtures/typing-medium.pyi]

[case testStrictEqualityNoPromotePy3]
# flags: --strict-equality
'a' == b'a'  # E: Non-overlapping equality check (left operand type: "Literal['a']", right operand type: "Literal[b'a']")
b'a' in 'abc'  # E: Non-overlapping container check (element type: "bytes", container item type: "str")

x: str
y: bytes
x != y  # E: Non-overlapping equality check (left operand type: "str", right operand type: "bytes")
[builtins fixtures/primitives.pyi]
[typing fixtures/typing-full.pyi]

[case testStrictEqualityOkPromote]
# flags: --strict-equality
from typing import Container
c: Container[int]

1 == 1.0  # OK
1.0 in c  # OK
[builtins fixtures/primitives.pyi]
[typing fixtures/typing-full.pyi]

[case testStrictEqualityAny]
# flags: --strict-equality
from typing import Any, Container

x: Any
c: Container[str]
x in c
x == 42
x is 42
[builtins fixtures/bool.pyi]
[typing fixtures/typing-full.pyi]

[case testStrictEqualityStrictOptional]
# flags: --strict-equality --strict-optional

x: str
if x is not None:  # OK even with strict-optional
    pass
[builtins fixtures/bool.pyi]

[case testStrictEqualityNoStrictOptional]
# flags: --strict-equality --no-strict-optional

x: str
if x is not None:  # OK without strict-optional
    pass
[builtins fixtures/bool.pyi]

[case testStrictEqualityEqNoOptionalOverlap]
# flags: --strict-equality --strict-optional
from typing import Optional

x: Optional[str]
y: Optional[int]
if x == y:  # E: Non-overlapping equality check (left operand type: "Optional[str]", right operand type: "Optional[int]")
    ...
[builtins fixtures/bool.pyi]

[case testCustomEqCheckStrictEquality]
# flags: --strict-equality
class A:
    def __eq__(self, other: A) -> bool:  # type: ignore
        ...
class B:
    def __eq__(self, other: B) -> bool:  # type: ignore
        ...

# Don't report non-overlapping check if there is already and error.
A() == B()  # E: Unsupported operand types for == ("A" and "B")
[builtins fixtures/bool.pyi]

[case testCustomEqCheckStrictEqualityOKInstance]
# flags: --strict-equality
class A:
    def __eq__(self, other: object) -> bool:
        ...
class B:
    def __eq__(self, other: object) -> bool:
        ...

A() == int()  # OK
int() != B()  # OK
[builtins fixtures/bool.pyi]

[case testCustomEqCheckStrictEqualityOKUnion]
# flags: --strict-equality
from typing import Union
class A:
    def __eq__(self, other: object) -> bool:
        ...

x: Union[A, str]
x == int()
[builtins fixtures/bool.pyi]

[case testCustomEqCheckStrictEqualityTuple]
# flags: --strict-equality
from typing import NamedTuple

class Base(NamedTuple):
    attr: int

class Custom(Base):
    def __eq__(self, other: object) -> bool: ...

Base(int()) == int()  # E: Non-overlapping equality check (left operand type: "Base", right operand type: "int")
Base(int()) == tuple()
Custom(int()) == int()
[builtins fixtures/bool.pyi]

[case testCustomEqCheckStrictEqualityMeta]
# flags: --strict-equality
class CustomMeta(type):
    def __eq__(self, other: object) -> bool: ...

class Normal: ...
class Custom(metaclass=CustomMeta): ...

Normal == int()  # E: Non-overlapping equality check (left operand type: "Type[Normal]", right operand type: "int")
Normal == Normal
Custom == int()
[builtins fixtures/bool.pyi]

[case testCustomContainsCheckStrictEquality]
# flags: --strict-equality
class A:
    def __contains__(self, other: A) -> bool:
        ...

# Don't report non-overlapping check if there is already and error.
42 in A()  # E: Unsupported operand types for in ("int" and "A")
[builtins fixtures/bool.pyi]

[case testStrictEqualityTypeVsCallable]
# flags: --strict-equality
from typing import Type, List
class C: ...
class D(C): ...
class Bad: ...

subclasses: List[Type[C]]
object in subclasses
D in subclasses
Bad in subclasses  # E: Non-overlapping container check (element type: "Type[Bad]", container item type: "Type[C]")
[builtins fixtures/list.pyi]
[typing fixtures/typing-full.pyi]

[case testStrictEqualityMetaclass]
# flags: --strict-equality
from typing import List, Type, Any

class Meta(type): ...
class OtherMeta(type): ...

class A(metaclass=Meta): ...
class B(metaclass=Meta): ...
class C(metaclass=OtherMeta): ...

o: Type[object]
a: Type[Any]
aa: type
exp: List[Meta]

A in exp
B in exp
C in exp  # E: Non-overlapping container check (element type: "Type[C]", container item type: "Meta")

o in exp
a in exp
aa in exp

a in [A, B]
aa in [A, B]

class AA: ...
class BB: ...
a in [AA, BB]
aa in [AA, BB]
[builtins fixtures/list.pyi]
[typing fixtures/typing-full.pyi]

[case testEmptyListOverlap]
# mypy: strict-equality
from typing import List

x: List[int]
x == []
[builtins fixtures/isinstancelist.pyi]

[case testCustomEqDecoratedStrictEquality]
# flags: --strict-equality
from typing import TypeVar, Callable, Any

F = TypeVar('F', bound=Callable[..., Any])

def deco(f: F) -> F: ...

class Custom:
    @deco
    def __eq__(self, other: object) -> bool: ...

Custom() == int()
[builtins fixtures/bool.pyi]

[case testCustomEqVarStrictEquality]
# flags: --strict-equality

class Custom:
    def compare(self, other: object) -> bool: ...
    __eq__ = compare

Custom() == int()
[builtins fixtures/bool.pyi]

[case testStrictEqualityDisabledWithTypeVarRestrictions]
# flags: --strict-equality
from typing import TypeVar

T = TypeVar('T', str, int)

def f(x: T) -> T:
    if x == int():  # OK
        ...
    return x
[builtins fixtures/bool.pyi]

[case testStrictEqualityWithALiteral]
# flags: --strict-equality
from typing_extensions import Literal, Final

def returns_a_or_b() -> Literal['a', 'b']:
    ...
def returns_1_or_2() -> Literal[1, 2]:
    ...
THREE: Final = 3

if returns_a_or_b() == 'c':  # E: Non-overlapping equality check (left operand type: "Literal['a', 'b']", right operand type: "Literal['c']")
    ...
if returns_1_or_2() is THREE:  # E: Non-overlapping identity check (left operand type: "Literal[1, 2]", right operand type: "Literal[3]")
    ...
[builtins fixtures/bool.pyi]

[case testStrictEqualityWithALiteralNewType]
# flags: --strict-equality
from typing import NewType

UserId = NewType('UserId', int)
FileId = NewType('FileId', str)

u: UserId
f: FileId

if u == 0:  # OK
    ...
if f == 0:  # E: Non-overlapping equality check (left operand type: "FileId", right operand type: "Literal[0]")
    ...
[builtins fixtures/bool.pyi]

[case testStrictEqualityPromotionsLiterals]
# flags: --strict-equality --py2
from typing import Final

U_FOO = u'foo'  # type: Final

if str() == U_FOO:
    pass
assert u'foo' == 'foo'
assert u'foo' == u'bar'  # E: Non-overlapping equality check (left operand type: "Literal[u'foo']", right operand type: "Literal[u'bar']")
[builtins_py2 fixtures/python2.pyi]

[case testStrictEqualityWithFixedLengthTupleInCheck]
# flags: --strict-equality
if 1 in ('x', 'y'):  # E: Non-overlapping container check (element type: "int", container item type: "str")
    pass
[builtins fixtures/tuple.pyi]
[typing fixtures/typing-full.pyi]

[case testOverlappingAnyTypeWithoutStrictOptional]
# flags: --no-strict-optional --strict-equality
from typing import Any, Optional

x: Optional[Any]

if x in (1, 2):
    pass
[builtins fixtures/tuple.pyi]
[typing fixtures/typing-full.pyi]

[case testUnimportedHintAny]
def f(x: Any) -> None:  # E: Name "Any" is not defined \
                        # N: Did you forget to import it from "typing"? (Suggestion: "from typing import Any")
    pass


[case testUnimportedHintAnyLower]
def f(x: any) -> None:  # E: Name "any" is not defined \
                        # N: Did you forget to import it from "typing"? (Suggestion: "from typing import Any")
    pass


[case testUnimportedHintOptional]
def f(x: Optional[str]) -> None:  # E: Name "Optional" is not defined \
                                  # N: Did you forget to import it from "typing"? (Suggestion: "from typing import Optional")
    pass

[case testAssertionLazilyWithIsNone]
from typing import Optional, List
li: Optional[List] = []
assert li is None, li[0]
[builtins fixtures/list.pyi]


[case testAssertionLazilyWithIsInstance]
from typing import Optional, List
li: Optional[List] = []
assert not isinstance(li,list), li[0]
[builtins fixtures/isinstancelist.pyi]

[case testAssertCurrentFrameIsNotUnreachable]
def f() -> int:  # E: Missing return statement
    x: int
    assert isinstance(x, int), '...'
[builtins fixtures/isinstance.pyi]

[case testTypeVarAsValue]
from typing import TypeVar
T = TypeVar("T")
x: int
x + T  # E: Unsupported operand types for + ("int" and "object")
T()  # E: "object" not callable