Black produced different code on the second pass of the formatter

[tcbegley]

Describe the bug

Ran black on some unit tests and got the error

 INTERNAL ERROR: Black produced different code on the second pass of the formatter.  Please report a bug on https://github.com/psf/black/issues.

I've included a minimal reproduction of the failing code below.

To Reproduce

1. Take this file

   def test_shape():
       assert some_function(
           data,
           more_data,
           kwarg1=kwarg1_longish_name,
           kwarg2=kwarg2_longish_name,
           kwarg3=kwarg3,
           kwarg4=kwarg4
       ).shape == (dim1_shape,)

2. Run Black on it with no arguments: black .

3. See error:

   error: cannot format test_shape.py: INTERNAL ERROR: Black produced different code on the second pass of the formatter.
   

Environment (please complete the following information):

• Version: master & 20.8b1
• OS and Python version: macOS + Python 3.8.6

Does this bug also happen on master?
Yes

Additional context

The first pass adds a trailing comma to kwarg4. The second pass wraps the expression in the assert statement in parentheses and expands onto multiple lines. Manually adding the trailing comma before running Black resolves the issue.

[mvolfik]

Probably the same issue as in #1629 , as black processes this file without issue with #1958 checked out

[ichard26]

Hello!

All reproduction cases in this issue format without error on master. The fixing commit was 8672af3 from PR GH-2126. I'll be marking this issue as a duplicate of GH-1629 since that's what GH-2126 aimed to fix and it's highly likely this issue falls under GH-1629.

Since we use the issue tracker as a reflection of what's on master, I'll be closing this issue. If you have any issues, especially with the new (but stable) output, please open a new issue. Oh and the fix should be available in a published release soon, see GH-2125 for more info.

Thank you for reporting!