TOML Trailing Comma bug

[ddelange]

Describe the bug

Hi 👋

TOML allows trailing comma in inline arrays ref toml-lang/toml#246 (comment).

Here's an example TOML where the trailing comma causes a bug (incorrect red highlight onwards): https://github.com/ddelange/mapply/blob/0.1.23/pyproject.toml#L60

[tool.ruff]
select = ["ALL"]
ignore = [
  "D107", # we have pydoclint with class docstring
  "D407", # we have google style docstrings
  "E501", # we have black
  "ANN", # we have mypy
  "TRY003", # there is EM102
  "D203", # there is D211
  "D213", # there is D212
  "FIX002", # there is TD002,TD003
]

[tool.ruff.extend-per-file-ignores]
"**/tests/**/*.py" = [
  "S101", # assert is fine in tests
  "D100", # tests is not a package
  "D104", # tests modules don't need docstrings
]

Expected behaviour

Code following the inline array with trailing comma should not have red highlight.

Related discussion

Additional notes

[lildude]

As per the troubleshooting doc, this is a problem with the upstream grammar. Please open an issue there.

[ahvigil]

is it possible the upstream grammar is being improperly applied somehow? The textmate toml bundle seems to parse fine in TextMate itself- but you can see even some of the official toml spec test cases show up with error highlights in the github rendering.

I can't pin this down exactly but I don't remember toml files rendering this way in the past and neither the toml spec nor the upstream grammar have changed in years. I feel like I would've noticed this in one of the many pyproject.toml files that now highlight in red. 🤷

[Alhadis]

@ahvigil This isn't the fault of the TextMate grammar. There appears to have been a change in GitHub's own PrettyLights highlighter; the grammar itself is valid and no changes to it are necessary. See #6603 (comment) for more details.

[lildude]

I've opened #6668 to track the highlighting issues in one place

[jtbandes]

Also, for what it's worth I believe the issue here is triggered by the line comment, not the trailing comma. It looks fine if I remove the last comment in the ignore list:

[tool.ruff]
select = ["ALL"]
ignore = [
  "D107", # we have pydoclint with class docstring
  "D407", # we have google style docstrings
  "E501", # we have black
  "ANN", # we have mypy
  "TRY003", # there is EM102
  "D203", # there is D211
  "D213", # there is D212
  "FIX002   ---> comment removed here",
]

[tool.ruff.extend-per-file-ignores]
"**/tests/**/*.py" = [
  "S101", # assert is fine in tests
  "D100", # tests is not a package
  "D104", # tests modules don't need docstrings
]