I observe the same issue as #22, using v1.0.1.

Starting with the file

from __future__ import annotations

from typing import Any, Callable, Mapping

MessageCallback = Callable[[Mapping[str, Any], Any], None]

def func(x: Mapping[str, Any], y: Any) -> None:
    return None

callback: MessageCallback
callback = func

This originally runs without errors, but not after running pep585-upgrade has run:

$ python -V
Python 3.8.6
$ python test.py
$ pre-commit run
Upgrade type hints.......................................................Failed
- hook id: upgrade-type-hints
- exit code: 1
- files were modified by this hook

Fixing src/workflows/test.py

isort....................................................................Failed
- hook id: isort
- files were modified by this hook

$ git diff
index 72539fc..56bc282 100644
--- a/test.py
+++ b/test.py
@@ -1,6 +1,7 @@
 from __future__ import annotations

-from typing import Any, Callable, Mapping
+from collections.abc import Mapping
+from typing import Any, Callable

 MessageCallback = Callable[[Mapping[str, Any], Any], None]

$ python test.py
Traceback (most recent call last):
  File "test.py", line 6, in <module>
    MessageCallback = Callable[[Mapping[str, Any], Any], None]
TypeError: 'ABCMeta' object is not subscriptable

The code-base I'm modernizing has the following code:

project_acl_list = cast(Optional[List[str]], project.acl)

Unfortunately, this is not transformed.

I'm willing to fix that, but I don't know yet how...

Could we discuss how to implement the transformation for this code?

Adding hook via:

  - repo: https://github.com/sondrelg/pep585-upgrade
    rev: ''
    hooks:
      - id: upgrade-type-hints
        args: [ '--futures=true' ]

When running in a python 3.9 virtualenv everything works, but switching to python 3.7 causes this error:

Upgrade type hints.......................................................Failed
- hook id: upgrade-type-hints
- exit code: 1

Traceback (most recent call last):
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/bin/upgrade-type-hints-script", line 8, in <module>
    sys.exit(main())
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/lib/python3.7/site-packages/src/upgrade_type_hints/main.py", line 33, in main
    annotation_list, imports, futures_import_found = find_annotations_and_imports_in_file(filename)
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/lib/python3.7/site-packages/src/upgrade_type_hints/checker.py", line 128, in find_annotations_and_imports_in_file
    imports, futures_import_found = map_imports(tree)
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/lib/python3.7/site-packages/src/upgrade_type_hints/checker.py", line 113, in map_imports
    imports[item.lineno]['end_lineno'] = item.end_lineno
AttributeError: 'Import' object has no attribute 'end_lineno'
Traceback (most recent call last):
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/bin/upgrade-type-hints-script", line 8, in <module>
    sys.exit(main())
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/lib/python3.7/site-packages/src/upgrade_type_hints/main.py", line 33, in main
    annotation_list, imports, futures_import_found = find_annotations_and_imports_in_file(filename)
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/lib/python3.7/site-packages/src/upgrade_type_hints/checker.py", line 128, in find_annotations_and_imports_in_file
    imports, futures_import_found = map_imports(tree)
  File "/home/some_name/.cache/pre-commit/repoh9mucjmj/py_env-python3.7/lib/python3.7/site-packages/src/upgrade_type_hints/checker.py", line 113, in map_imports
    imports[item.lineno]['end_lineno'] = item.end_lineno
AttributeError: 'Import' object has no attribute 'end_lineno'

Running pre-commit autoupdate leads to the following result: Updating https://github.com/sondrelg/pep585-upgrade ... updating v1.0.1 -> v1.

Running pre-commit autoupdate again will result in the following warning:

[WARNING] The 'rev' field of repo 'https://github.com/sondrelg/pep585-upgrade' appears to be a mutable reference (moving tag / branch).
Mutable references are never updated after first install and are not supported. 
See https://pre-commit.com/#using-the-latest-version-for-a-repository for more details. 
Hint: `pre-commit autoupdate` often fixes this.

It would be cool if pre-commit autoupdate would work on this hook as expected. I suspect that the problem is that all 3 tags point to the same commit.

Summary

When the python file consists of module docstring, the formatter inserts the from __future__ import annotation on the top of the docstring.

Previous Behavior

Source

#! /usr/env/bin python
"""don't touch the doc string

multi line boss
"""
from typing import List

a: List[int] = [1, 2]


def foo():
    """I'm a doc string"""
    pass

Generated

from __future__ import annotations


#! /usr/env/bin python
"""don't touch the doc string

multi line boss
"""

a: list[int] = [1, 2]


def foo():
    """I'm a doc string"""

The PR adds a function to find the module docstring. It will insert future import after the module docstring.

Input:

#!/usr/bin/env python3
from typing import AbstractSet

s: AbstractSet

Output:

from collections.abc import Set
#!/usr/bin/env python3

s: Set

I didn't prepare the fix yet, but I think that the best solution would be to save the first occurrence of non-comment, non-docstring expressions while scanning AST and put the imports before that. What do you think?

Hi guys, Thanks a lot for this great package, it makes the code much more pythonic! I have one favor: could you create/push a tag for the package? Else I have this annoying warning:

[WARNING] The 'rev' field of repo 'https://github.com/snok/pep585-upgrade' appears to be a mutable reference (moving tag / branch).  Mutable references are never updated after first install and are not supported.  See https://pre-commit.com/#using-the-latest-version-for-a-repository for more details.

For an input file like this:

from collections.abc import Callable

from typing import Collection

def a(a: Callable, b: Collection):
    pass

when applying pep585 hook I get:

from collections.abc import Collection
from collections.abc import Callable

def a(a: Callable, b: Collection):
    pass

while I expect:

from collections.abc import Callable, Collection

def a(a: Callable, b: Collection):
    pass

It could be argued this is the job of e.g. isort, however - pep585-upgrade already tries to be nice in terms of imports - e.g. in a larger import set - this new import line gets added nearby other import from same package and not at the end (which would be simplest I guess)

The typing package supports generics, whereas collections.abc does not. Hence, when this tool replaces typing types that are used as generics with their equivalent types in collections.abc, it breaks the build. I found it helpful to run this tool as a one-off and then manually undo these cases though, so thank you!

Minimal working example:

Input:

from typing import Any, Type, TypeVar

t: Type

Output:

from typing import AnyVar

t: type

I have a fix for this already. Please wait for a PR with a fix and tests.

I got an error from pre-commit which suggested it was looking for a .pre-commit-config.yaml file, when I changed the filename, as in this commit.

Possibly OS specific, this was on MacOS Big Sur, Python 3.9.