[IntelliSense] allow applying quick fixes all at once per file, like common IntelliSense providers

[AFCMS]

I have several codebases made before the VSCode extension started displaying suggestCanonicalClasses warnings. Those tend to have a lot of warning like these, and LLMs tend to generate non-canonical classes as well.

The extension provide quick fixes for those warnings, but only on a per-warning basis. Common IntelliSense providers like ESLint, TypeScript, etc provide quick fix actions to apply all fixes available for a given warning type in a file.

It would be a nice QoL feature to have.

[DucMinhNe]

This would be a very welcome quality-of-life addition. The reason it currently works only on a per-warning basis comes down to how @tailwindcss/language-server advertises its LSP CodeAction capabilities.

How VS Code Handles "Fix All in File"

In the Language Server Protocol (LSP), batch code actions require the language server to register either:

1. A composite CodeAction with kind: CodeActionKind.SourceFixAll (e.g. source.fixAll or source.fixAll.tailwind), or
2. A collective action whose WorkspaceEdit aggregates the text replacements for all matching suggestCanonicalClasses diagnostic ranges across the active document.

Right now, the Tailwind language server emits individual CodeActionKind.QuickFix entries per diagnostic without exposing an aggregated source.fixAll provider. Implementing source.fixAll.tailwind would also allow users to bind it to automatic save actions in settings.json:

"editor.codeActionsOnSave": {
  "source.fixAll.tailwind": "explicit"
}

Workarounds Available Today for Large Codebases

If you have many legacy files with dozens of non-canonical warnings:

1. Official CLI Codemod:
   You can run the official Tailwind upgrade tool:

   npx @tailwindcss/upgrade

   Even on already-upgraded v4 codebases, it scans templates and batch-normalizes non-canonical utility classes project-wide.

2. Linter / Formatter rules:
   If you have prettier-plugin-tailwindcss or eslint-plugin-tailwindcss configured, running npx prettier --write . or eslint --fix can batch-format and normalize classes across entire directories.