xslint

Lint your XSL/XSLT stylesheets as you type — malformed XML, invalid XPath, and stylistic defects — with quick-fixes, powered by xslint. Works in any VS Code-compatible editor.

Install

This extension is published on Open VSX and attached as a .vsix to every release. It is not on the Microsoft VS Code Marketplace.

Cursor, VSCodium, Windsurf

These editors use Open VSX as their gallery — open the Extensions view, search xslint, and click Install.

Gitpod

Add it to .gitpod.yml:

vscode:
  extensions:
    - maxonfjvipon.xslint-vscode

VS Code (Microsoft build)

VS Code searches only Microsoft's Marketplace, where this extension is not listed, so install from the .vsix:

code --install-extension xslint-vscode-<version>.vsix

Or download the .vsix from the latest release and run Extensions view → ⋯ → Install from VSIX….

Any other LSP editor

The language server is editor-agnostic; point your client at it as described in xslint-lsp.

Once installed, open any .xsl/.xslt file — diagnostics appear as you type, no save or build needed.

Features

• Live diagnostics — the checks your project's .xslint.yml runs, or xslint's recommended ones without it, go over the buffer as you edit, surfacing problems with their exact line and column, no save or build needed.
• Your configuration — preset:, only:, rules: and exclude: in .xslint.yml mean in the editor exactly what they mean to the command line, a problem with the file shows up on the file itself, and an edit to it re-checks what you have open.
• Quick-fixes — a lightbulb on each fixable defect, plus a fix all action for the safe fixes. The edits come from xslint's own engine, so a fix in the editor is what a command-line xslint --fix-suggestions writes, and fix all what xslint --fix writes.
• Any .xsl/.xslt file — activates automatically.

How it works

The extension bundles and launches the xslint-lsp language server, which wraps xslint and speaks the Language Server Protocol. Because the same server is editor-agnostic, xslint diagnostics are available in any LSP-capable editor.

License

MIT