Using a pipe symbol in typing.Literal string

[haakonvt]

Bug Report

Using mypy 1.6.1, I'm unable to use a pipe symbol in a string used in typing.Literal:

To Reproduce

from typing import Literal

def fn(x: Literal["foo", "bar", "foo|bar"]) -> None:
    reveal_type(x)

Expected Behavior
No issue with "foo|bar".

Actual Behavior

This gives the following output:

bb_mypy.py:4: error: Name "foo" is not defined  [name-defined]
    def fn(x: Literal["foo", "bar", "foo|bar"]) -> None:
                                    ^
bb_mypy.py:5: note: Revealed type is "Any"
Found 1 error in 1 file (checked 1 source file)

Your Environment

• Python version used: 3.8.18
• Mypy version used: 1.6.1
• Mypy command-line flags: None were used.
• Mypy configuration options from mypy.ini (and other config files):

1. pretty = true
2. check_untyped_defs = true
3. ignore_missing_imports = false
4. disallow_untyped_defs = true
5. follow_imports = normal
6. namespace_packages = true
7. explicit_package_bases = true
8. show_error_codes = true
9. plugins = numpy.typing.mypy_plugin
10. no_implicit_reexport = true
11. no_implicit_optional = true
12. warn_redundant_casts = true
13. warn_unused_ignores = true

[AlexWaygood]

Duplicate of #16367

[haakonvt]

Duplicate of #16367

I'd argue #16367 is a duplicate of this one (as I was the one to discover it) and the other was created while I slowly typed this issue up 😅 But nevermind!

[AlexWaygood]

I'd argue #16367 is a duplicate of this one (as I was the one to discover it) and the other was created while I slowly typed this issue up 😅 But nevermind!

It's a dog-eat-dog world out here on the mypy issue tracker, I'm afraid ;)

[InSyncWithFoo]

Sorry :) I was about to let you know before creating this issue, but you posted this comment saying that you would "open an issue if this question does not receive a possible workaround/solution within a few days".