flynt checks breaking with package update to flynt-0.78

[bdperkin]

Describe the bug
TypeError when executing darker --flynt which had been working with flynt-0.77

To Reproduce
Steps to reproduce the behavior:

1. In a fresh virtualenv, pip3 install darker[flynt]
2. Verify versions: pip3 freeze | grep -E "^(darker|flynt)" (currently: darker==1.7.0 and flynt==0.78)
3. Run Darker with darker --flynt
4. Get Traceback:

$ pip3 freeze | grep -E "^(darker|flynt)"
darker==1.7.0
flynt==0.78
$ darker --flynt
Traceback (most recent call last):
  File "${PWD}/venv/bin/darker", line 8, in <module>
    sys.exit(main_with_error_handling())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/__main__.py", line 630, in main_with_error_handling
    return main()
           ^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/__main__.py", line 586, in main
    for path, old, new in sorted(
                          ^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/__main__.py", line 107, in format_edited_parts
    ) = future.result()
        ^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/concurrent/futures/_base.py", line 449, in result
    return self.__get_result()
           ^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/concurrent/futures/_base.py", line 401, in __get_result
    raise self._exception
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/concurrency.py", line 48, in submit
    result = fn(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/__main__.py", line 151, in _modify_and_reformat_single_file
    content_after_reformatting = _blacken_and_flynt_single_file(
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/__main__.py", line 202, in _blacken_and_flynt_single_file
    fstringified = _maybe_flynt_single_file(
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/__main__.py", line 264, in _maybe_flynt_single_file
    return apply_flynt(rev2_isorted, relpath_in_rev2, edited_linenums_differ)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/fstring.py", line 59, in apply_flynt
    return _call_flynt_fstringify(content)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "${PWD}/venv/lib64/python3.11/site-packages/darker/fstring.py", line 70, in _call_flynt_fstringify
    result, _ = flynt_fstringify_code_by_line(content.string)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: fstringify_code_by_line() missing 1 required positional argument: 'state'

Expected behavior
No traceback and functioning as it did with flynt==0.78

Environment

• LSB Version: :core-4.1-amd64:core-4.1-noarch
• Distributor ID: Fedora
• Description: Fedora release 37 (Thirty Seven)
• Release: 37
• Codename: ThirtySeven
• Python version: Python 3.11.2
• Git version: git version 2.39.2
• Darker version: 1.7.0
• Black version: black, 23.1.0 (compiled: yes); Python (CPython) 3.11.2
• isort version: VERSION 5.10.1
• flynt version: 0.78

Additional context
Running flynt standalone with this version is working.
Seems this may be the change that caused the issue: ikamensh/flynt@e66e7f6

[akaihola]

Thanks @bdperkin for the heads-up! This seems easy enough to fix.

I'll also consider adding similar similar automated "future" tests as we already have for upcoming Black versions (see #382 and #430).

Update: I added #473 to track this.

[jedie]

(currently: darker==1.7.0 and flynt==0.78)

I ran into the same problem with darker==1.7.1 and flynt==0.78 :(

[jedie]

Oh it's my fault: The fix is to install flynt/isort/Pygments via darker "extras", to get always compatibility version combinations, isn't it?

[akaihola]

Hi @jedie; yes, Flynt 0.78 compatibility will be fixed soon (see #480), and meanwhile pip install 'darker[flynt]' will ensure a compatible version of Flynt is used.