test-data/unit/check-union-or-syntax.test

-- Type checking of union types with '|' syntax

[case testUnionOrSyntaxWithTwoBuiltinsTypes]
# flags: --python-version 3.10
from __future__ import annotations
def f(x: int | str) -> int | str:
    reveal_type(x)  # N: Revealed type is 'Union[builtins.int, builtins.str]'
    z: int | str = 0
    reveal_type(z)  # N: Revealed type is 'Union[builtins.int, builtins.str]'
    return x
reveal_type(f)  # N: Revealed type is 'def (x: Union[builtins.int, builtins.str]) -> Union[builtins.int, builtins.str]'
[builtins fixtures/tuple.pyi]


[case testUnionOrSyntaxWithThreeBuiltinsTypes]
# flags: --python-version 3.10
def f(x: int | str | float) -> int | str | float:
    reveal_type(x)  # N: Revealed type is 'Union[builtins.int, builtins.str, builtins.float]'
    z: int | str | float = 0
    reveal_type(z)  # N: Revealed type is 'Union[builtins.int, builtins.str, builtins.float]'
    return x
reveal_type(f)  # N: Revealed type is 'def (x: Union[builtins.int, builtins.str, builtins.float]) -> Union[builtins.int, builtins.str, builtins.float]'


[case testUnionOrSyntaxWithTwoTypes]
# flags: --python-version 3.10
class A: pass
class B: pass
def f(x: A | B) -> A | B:
    reveal_type(x)  # N: Revealed type is 'Union[__main__.A, __main__.B]'
    z: A | B = A()
    reveal_type(z)  # N: Revealed type is 'Union[__main__.A, __main__.B]'
    return x
reveal_type(f)  # N: Revealed type is 'def (x: Union[__main__.A, __main__.B]) -> Union[__main__.A, __main__.B]'


[case testUnionOrSyntaxWithThreeTypes]
# flags: --python-version 3.10
class A: pass
class B: pass
class C: pass
def f(x: A | B | C) -> A | B | C:
    reveal_type(x)  # N: Revealed type is 'Union[__main__.A, __main__.B, __main__.C]'
    z: A | B | C = A()
    reveal_type(z)  # N: Revealed type is 'Union[__main__.A, __main__.B, __main__.C]'
    return x
reveal_type(f)  # N: Revealed type is 'def (x: Union[__main__.A, __main__.B, __main__.C]) -> Union[__main__.A, __main__.B, __main__.C]'


[case testUnionOrSyntaxWithLiteral]
# flags: --python-version 3.10
from typing_extensions import Literal
reveal_type(Literal[4] | str)  # N: Revealed type is 'Any'
[builtins fixtures/tuple.pyi]


[case testUnionOrSyntaxWithBadOperator]
# flags: --python-version 3.10
x: 1 + 2  # E: Invalid type comment or annotation


[case testUnionOrSyntaxWithBadOperands]
# flags: --python-version 3.10
x: int | 42  # E: Invalid type: try using Literal[42] instead?
y: 42 | int  # E: Invalid type: try using Literal[42] instead?
z: str | 42 | int  # E: Invalid type: try using Literal[42] instead?


[case testUnionOrSyntaxWithGenerics]
# flags: --python-version 3.10
from typing import List
x: List[int | str]
reveal_type(x)  # N: Revealed type is 'builtins.list[Union[builtins.int, builtins.str]]'
[builtins fixtures/list.pyi]


[case testUnionOrSyntaxWithQuotedFunctionTypes]
# flags: --python-version 3.4
from typing import Union
def f(x: 'Union[int, str, None]') -> 'Union[int, None]':
    reveal_type(x)  # N: Revealed type is 'Union[builtins.int, builtins.str, None]'
    return 42
reveal_type(f)  # N: Revealed type is 'def (x: Union[builtins.int, builtins.str, None]) -> Union[builtins.int, None]'

def g(x: "int | str | None") -> "int | None":
    reveal_type(x)  # N: Revealed type is 'Union[builtins.int, builtins.str, None]'
    return 42
reveal_type(g)  # N: Revealed type is 'def (x: Union[builtins.int, builtins.str, None]) -> Union[builtins.int, None]'


[case testUnionOrSyntaxWithQuotedVariableTypes]
# flags: --python-version 3.6
y: "int | str" = 42
reveal_type(y)  # N: Revealed type is 'Union[builtins.int, builtins.str]'


[case testUnionOrSyntaxWithTypeAliasWorking]
# flags: --python-version 3.10
from typing import Union
T = Union[int, str]
x: T
reveal_type(x)  # N: Revealed type is 'Union[builtins.int, builtins.str]'


[case testUnionOrSyntaxWithTypeAliasNotAllowed]
# flags: --python-version 3.9
from __future__ import annotations
T = int | str  # E: Unsupported left operand type for | ("Type[int]")
[builtins fixtures/tuple.pyi]


[case testUnionOrSyntaxInComment]
# flags: --python-version 3.6
x = 1  # type: int | str


[case testUnionOrSyntaxFutureImport]
# flags: --python-version 3.7
from __future__ import annotations
x: int | None
[builtins fixtures/tuple.pyi]


[case testUnionOrSyntaxMissingFutureImport]
# flags: --python-version 3.9
x: int | None  # E: X | Y syntax for unions requires Python 3.10


[case testUnionOrSyntaxInStubFile]
# flags: --python-version 3.6
from lib import x
[file lib.pyi]
x: int | None