`type: ignore` command not recognized after other comment

[Paulchen5]

Bug Report

mypy isn't recognizing type: ignore if it is after some other comment, e.g.:

tree1.compare_structural_equality(None)  # pyright: ignore[reportArgumentType] # type: ignore[arg-type]

To Reproduce

method strcuture (copied):

(method) def compare_structural_equality(
    obj: Tree,
    message_object: MessageObject = MessageObject("")
) -> bool
Compare the structure of this tree with another tree.

Args
obj : Tree
The tree to compare with.

message_object : MessageObject
Object to store messages about differences.

Returns
bool
True if structures are equal, False otherwise.

tree1.compare_structural_equality(None)  # type: ignore[arg-type] # pyright: ignore[reportArgumentType]

=> works 👍

tree1.compare_structural_equality(None)  # pyright: ignore[reportArgumentType] # type: ignore[arg-type]

=> doesn't works 🤷

Expected Behavior

Bove examples work

Actual Behavior

Only the first example works

Your Environment

• Mypy version used: mypy 1.16.1 (compiled: yes)
• Mypy command-line flags: none
• Mypy configuration options from mypy.ini (and other config files): from pyproject.toml

[tool.mypy]
python_version = "3.12"
ignore_missing_imports = true
strict = true
show_error_codes = true

• Python version used: Python 3.12.0

I am sorry If I missed an explanation for this. I also don't know if it is appropriate to use mypy and pyright.

In my opinion both examples should work.

[brianschubert]

Unfortunately, mypy currently can only support outer # type: ignore comments. This is because mypy uses the standard library ast module for parsing, which only stores outer # type: ignore comments in the AST.

Compare:

# outer type ignore, stored in AST
>>> ast.parse(
...     "tree1.compare_structural_equality(None)  # type: ignore[arg-type] # pyright: ignore[reportArgumentType]", 
...     type_comments=True,
... )
Module(body=[Expr(value=Call(func=Attribute(...), args=[Constant(...)], keywords=[]))], type_ignores=[TypeIgnore(lineno=1, tag='[arg-type] # pyright: ignore[reportArgumentType]')])

# inner type ignore, not stored in AST
>>> ast.parse(
...     "tree1.compare_structural_equality(None)  # pyright: ignore[reportArgumentType] # type: ignore[arg-type]",
...     type_comments=True,
... )
Module(body=[Expr(value=Call(func=Attribute(...), args=[Constant(...)], keywords=[]))], type_ignores=[])

This is also why mypy currently can't support # mypy: ignore comments, for example.

It is possible that mypy will be able to support this in the future if/when there is a switch to a different parser or if the ast module gains support for tracking these sort of comments. But for now, there isn't anything that mypy can do to improve this.

Also note that using # pyright: ignore on a line with a # type: ignore comment is generally unnecessarily. Pyright will suppress all type checking diagnostics on lines with a # type: ignore comment, regardless of the contents of the tag in square brackets.

[Paulchen5]

Ah ok and you for the additional info with pyright 👍

[jorenham]

Pyright will suppress all type checking diagnostics on lines with a # type: ignore comment, regardless of the contents of the tag in square brackets.

Unless you have enableTypeIgnoreComments=false in your config :)
https://microsoft.github.io/pyright/#/configuration?id=type-evaluation-settings

[Paulchen5]

I'll have to check this👍