🐛 Line endings are ignored (CRLF)

[baptistemarchand]

VS Code version

1.101.2

Extension version

3.1.0

Biome version

2.1.1

Operating system

• Windows
• macOS
• Linux

Description

The VSCode extension is not removing \r characters at the end of lines (but the CLI is).

Steps to reproduce

Here is a repo : https://github.com/baptistemarchand/biome-crlf
The file crlf.ts contains windows style line endings.
Running yarn biome format shows errors :

Open the file in VSCode and save.
The line endings are not fixed (the repo includes a .vscode/settings.json file with editor.formatOnSave: true).

Expected behavior

I expected the line endings to be fixed (\r\n => \n) when I saved the file.

If I use the CLI (yarn biome format --fix), it works as expected.

Does this issue occur when using the CLI directly?

No

Link to a minimal reproduction

https://github.com/baptistemarchand/biome-crlf

Logs

[nhedger]

Not sure what is happening here.

Looking at the LSP trace, I can see that Biome instructs VS Code to remplace 3 ranges with \n as expected, but indeed the text is not updated in the editor and the file shows no changes in git.

2025-07-15 15:26:39.816 [info] [Trace - 15:26:39] Received response 'textDocument/formatting - (13)' in 1ms.
2025-07-15 15:26:39.816 [info] Result: [
    {
        "newText": "\n",
        "range": {
            "end": {
                "character": 0,
                "line": 1
            },
            "start": {
                "character": 17,
                "line": 0
            }
        }
    },
    {
        "newText": "\n",
        "range": {
            "end": {
                "character": 0,
                "line": 2
            },
            "start": {
                "character": 18,
                "line": 1
            }
        }
    },
    {
        "newText": "\n",
        "range": {
            "end": {
                "character": 0,
                "line": 3
            },
            "start": {
                "character": 2,
                "line": 2
            }
        }
    }
]

[fabianszabo]

@baptistemarchand I believe you opened the ticket in the wrong repository. This seems to be an issue with the formatter rather than the extension (this is the vs-code extension repository).

Please open a new issue, and use the latest version if possible. We don't push fixes to old versions

biomejs/biome#5087

[baptistemarchand]

@baptistemarchand I believe you opened the ticket in the wrong repository. This seems to be an issue with the formatter rather than the extension (this is the vs-code extension repository).

Please open a new issue, and use the latest version if possible. We don't push fixes to old versions

biomejs/biome#5087

@fabianszabo The formatter in the CLI is working as intended. The bug only happens in the VSCode extension.
That's why I created the issue here.

[nhedger]

While it's unlikely that the extension is responsible for this, AFAICT, Biome isn't responsible either. It seems that VS Code doesn't correctly replace the text in the ranges.

[fabianszabo]

I wonder if there is a difference between the calls sent to VS Code when formatting using the CLI directly vs using the extension (using the lsp-proxy). I can't imagine that they are exactly the same.

[nhedger]

When you format using the CLI, Biome directly writes to the files, but when using the LSP, we instead give VS Code a list of edits to make to the file.

[nhedger]

As far as I can tell, VS Code normalizes line endings automatically. That would explain why the changes are computed correctly, but you still don’t see them applied. Fixing this would likely require the LSP server to send a custom notification to the extension, with the extension then calling edit.setEndOfLine.

I’m not sure whether we can reliably detect when a formatting operation changes the line endings in a way that would let us trigger that notification.