css-tree/lib/syntax/index.js

A tool set for CSS: fast detailed parser (CSS → AST), walker (AST traversal), generator (AST → CSS) and lexer (validation and matching) based on specs and browser implementations

import createSyntax from './create.js';
import lexerConfig from './config/lexer.js';
import parserConfig from './config/parser.js';
import walkerConfig from './config/walker.js';

export default createSyntax({
    ...lexerConfig,
    ...parserConfig,
    ...walkerConfig
});