Exception raised on sorting stdin with isort:skip_file

[epage]

isort version 5.8.0

We put isort:skip_file in some of our code-gen files. When we run isort across the entire repo, it works.

Recently, we've integrated isort into something like a pre-commit hook (arc diff). Since we were combining it with Black, we pipe things through stdin/stdout but we are hitting errors with isort:skip_file.

Traceback (most recent call last):
  File "/Users/edpage/.cache/venv/lib/python3.9/site-packages/isort/api.py", line 185, in sort_stream
    changed = core.process(
  File "/Users/edpage/.cache/venv/lib/python3.9/site-packages/isort/core.py", line 151, in process
    raise FileSkipComment("Passed in content")
isort.exceptions.FileSkipComment: Passed in content contains an file skip comment and was skipped.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/edpage/.cache/venv/bin/isort", line 8, in <module>
    sys.exit(main())
  File "/Users/edpage/.cache/venv/lib/python3.9/site-packages/isort/main.py", line 1085, in main
    api.sort_stream(
  File "/Users/edpage/.cache/venv/lib/python3.9/site-packages/isort/api.py", line 192, in sort_stream
    raise FileSkipComment(content_source)
isort.exceptions.FileSkipComment: Passed in content contains an file skip comment and was skipped.

When processing files, isort catches this and records it as a skip. When processing streams, nothing catches the exception and continues to stream out the content, as I would expect.

There are various changes we can make to our hook but they seem like we'd be re-implementing logic in isort and that addressing this in isort in some way would be more correct.

[timothycrosley]

I agree this is not ideal! I've done my best to address this here: #1706. When streaming (from the commandline utility), if isort encounters a skip file comment, instead of raising an exception - it will now stream the remainder of the file without modification.