tree-sitter-css-strict

A tree-sitter grammar for strict CSS, for standalone stylesheets. It is a maintained fork of tree-sitter/tree-sitter-css that tracks upstream CSS syntax but treats // as invalid outside strings and URLs, as browsers do. The upstream grammar accepts JavaScript-style line comments for injected CSS, which can hide broken stylesheets in a standalone file. This grammar also accepts valid unquoted relative URLs such as url(../fonts/a.eot); protocol-relative URLs such as url(//cdn.example.com/a.png), double slashes in strings, and /* block comments */ remain valid.

Installation

Rust:

cargo add tree-sitter tree-sitter-css-strict

Node:

npm install tree-sitter-css-strict

A GitHub Packages copy is also published as @alfpricot/tree-sitter-css-strict.

Requirements

• Rust 1.85 or later (rust-version in Cargo.toml) for the crate.
• A C compiler, because both bindings compile the generated parser (src/parser.c) and src/scanner.c; the Node binding falls back to compiling when no prebuilt binary matches the platform.
• Node 24 for development (.nvmrc); the tree-sitter peer dependency is ^0.25.0 and is optional.

Usage

Rust:

let mut parser = tree_sitter::Parser::new();
let language = tree_sitter_css_strict::LANGUAGE;
parser
    .set_language(&language.into())
    .expect("Error loading strict CSS parser");
let tree = parser.parse("a { color: red; }", None).unwrap();
assert!(!tree.root_node().has_error());

Node:

import Parser from 'tree-sitter';
import CSS from 'tree-sitter-css-strict';

const parser = new Parser();
parser.setLanguage(CSS);

The Rust crate exports HIGHLIGHTS_QUERY; the Node binding exposes it as CSS.HIGHLIGHTS_QUERY. See ARCHITECTURE.md for how the grammar, bindings, and queries fit together.

How to contribute

Branch from dev, run tree-sitter generate after every grammar.js change, and commit the regenerated parser files with it. Run tree-sitter test, cargo test, npm run lint, and npm run format:check before opening a pull request. CONTRIBUTING.md has the exact commands.

License

MIT. See LICENSE and NOTICE.