When both Ruff and isort run on-save, last line of file is repeated

[charliermarsh]

This may well be a Ruff problem but I'm having trouble understanding it, and it only occurs when both Ruff and isort are installed together, so I thought it was worth raising here.

When both Ruff and isort are installed, and configured to organize imports on save, the last line of the file ends up being repeated on-save.

For example, given:

import sys
from setuptools import setup

aa

And this settings.json:

{
    "isort.importStrategy": "useBundled",
    "ruff.importStrategy": "useBundled",
    "editor.formatOnSave": false,
    "editor.codeActionsOnSave": {
        "source.fixAll": false,
        "source.organizeImports": true
    }
}

Then on-save, I get:

import sys

from setuptools import setup

aa
aa

Disabling either extension causes the file to format properly.

I think this has to do with the use of len(document.lines) to format the "whole file" edit, but I would've thought that the "versioned" edits would avoid this issue.

You might decide that this either (1) Ruff's problem, or (2) user error (given that you shouldn't really have two plugins organizing imports), but this does seem like unexpected behavior and possibly indicative of bug in either or both extension.

[karthiknadig]

@charliermarsh do both the extensions run the formatting? Can you share the logs from isort and Ruff?

FYI, In the next release of the python extension, we won't be installing isort. Going forward, people will not have isort extension by default.

[charliermarsh]

Yeah I believe they both run.

I don't get much from the isort logs (I should probably clone it, run locally, and add more logging):

/usr/local/bin/python -m isort - --filename /Users/crmarsh/workspace/ruff/setup.py
CWD Linter: /Users/crmarsh/workspace/ruff

I added some very verbose logging to ruff locally:

code_action: CodeActionParams(text_document=TextDocumentIdentifier(uri='file:///Users/crmarsh/workspace/ruff/setup.py'), range=0:0-3:2, context=CodeActionContext(diagnostics=[Diagnostic(range=0:7-0:10, message='`sys` imported but unused', severity=<DiagnosticSeverity.Warning: 2>, code='F401', code_description=None, source='Ruff', tags=[<DiagnosticTag.Unnecessary: 1>], related_information=None, data={'content': '', 'message': 'Remove unused import: `sys`', 'location': {'row': 1, 'column': 0}, 'end_location': {'row': 2, 'column': 0}}), Diagnostic(range=1:23-1:28, message='`setuptools.setup` imported but unused', severity=<DiagnosticSeverity.Warning: 2>, code='F401', code_description=None, source='Ruff', tags=[<DiagnosticTag.Unnecessary: 1>], related_information=None, data={'content': '', 'message': 'Remove unused import: `setuptools.setup`', 'location': {'row': 2, 'column': 0}, 'end_location': {'row': 3, 'column': 0}}), Diagnostic(range=3:0-3:2, message='Undefined name `aa`', severity=<DiagnosticSeverity.Warning: 2>, code='F821', code_description=None, source='Ruff', tags=None, related_information=None, data=None)], only=['source.organizeImports'], trigger_kind=None), work_done_token=None, partial_result_token=None)
Running Ruff with: ['/Users/crmarsh/workspace/vscode-ruff/bundled/libs/bin/ruff', '--no-cache', '--no-fix', '--quiet', '--format', 'json', '-', '--fix', '--extend-ignore', 'ALL', '--extend-select', 'I001', '--stdin-filename', '/Users/crmarsh/workspace/ruff/setup.py']
Number of lines: 4
lines: ['import sys\n', 'from setuptools import setup\n', '\n', 'aa']
source: import sys
from setuptools import setup

aa
edits_version = 36
results = [TextEdit(range=0:0-4:0, new_text='import sys\n\nfrom setuptools import setup\n\naa')]
Running Ruff with: ['/Users/crmarsh/workspace/vscode-ruff/bundled/libs/bin/ruff', '--no-cache', '--no-fix', '--quiet', '--format', 'json', '-', '--stdin-filename', '/Users/crmarsh/workspace/ruff/setup.py']
Running Ruff with: ['/Users/crmarsh/workspace/vscode-ruff/bundled/libs/bin/ruff', '--no-cache', '--no-fix', '--quiet', '--format', 'json', '-', '--stdin-filename', '/Users/crmarsh/workspace/ruff/setup.py']
Running Ruff with: ['/Users/crmarsh/workspace/vscode-ruff/bundled/libs/bin/ruff', '--no-cache', '--no-fix', '--quiet', '--format', 'json', '-', '--stdin-filename', '/Users/crmarsh/workspace/ruff/setup.py']
code_action: CodeActionParams(text_document=TextDocumentIdentifier(uri='file:///Users/crmarsh/workspace/ruff/setup.py'), range=5:2-5:2, context=CodeActionContext(diagnostics=[Diagnostic(range=5:0-5:2, message='Undefined name `aa`', severity=<DiagnosticSeverity.Warning: 2>, code='F821', code_description=None, source='Ruff', tags=None, related_information=None, data=None)], only=None, trigger_kind=None), work_done_token=None, partial_result_token=None)

After the edit, if I hit Command + Z once, I get:

import sys

from setuptools import setup

aa

If I hit it again, I'm back to:

import sys
from setuptools import setup

aa

[charliermarsh]

My guess is that they're both generating the edit, and trying to apply it to lines 0-to-3 (or rather, start of line 0 to start of line 4). When the "second" formatter runs, the previous last-line is now on line 4, since we inserted a newline between the sys and setuptools imports. So we end up re-inserting that last line, rather than overwriting it.

[karthiknadig]

This might actually be a VS Code bug. It should not be running both the import organizers. It should be running only one. The thing is I don't think we are even getting diferent versions here. I suspect we may be getting the same version.

[karthiknadig]

Both get the same version:

This is Ruff

This is isort

[karthiknadig]

Closing against microsoft/vscode#174295