Misleading error message when Language Server doesn't support range formatting

[rotu]

Type: Bug

1. Install extension denoland.vscode-deno and enable it for a project.
2. Open a TypeScript file.
3. Select a range, choose "Format Selection With..." and choose the Deno extension

Observe the error message:

Extension 'Deno' is configured as formatter but it cannot format 'TypeScript'-files

This is misleading, as the Deno Language Server does support TypeScript files. It supports document formatting but not range formatting.

Further, setting editor.formatOnSaveMode: "modificationsIfAvailable" or "modifications" gives the same misleading error message on save.

Originally reported at denoland/vscode_deno#860

VS Code version: Code 1.80.1 (74f6148, 2023-07-12T17:20:58.115Z)
OS version: Darwin arm64 23.0.0
Modes:

[jrieken]

Select a range, choose "Format Selection With..." and choose the Deno extension

This doesn't reproduce for me, having TS and deno installed and I do not see that option because not two or more range formatter are installed, it's just TS

[rotu]

@jrieken repro is slightly different for me with the latest versions (VS Code 1.84.2, denoland.vscode-deno 3.28.0). I too can no longer see Deno in the "Format Selection With..." dropdown.

I can still repro by having Deno as my default formatter and then choosing the "Format Selection" Command.

[jrieken]

Thanks, I can reproduce with

• install deno
• configure as default formatter (see below)
• make a selection
• trigger format selection
• 🐛 message blames deno in an unpresice way

 "[typescript]": {
    "editor.defaultFormatter": "denoland.vscode-deno"
  },

[vscodenpa]

This feature request is now a candidate for our backlog. The community has 60 days to upvote the issue. If it receives 20 upvotes we will move it to our backlog. If not, we will close it. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!

[jrieken]

To verify follow these steps #188441 (comment) and ensure the message is good