adobe@adobe/css-tools
A modern CSS parser and stringifier with TypeScript support
Parse CSS into an Abstract Syntax Tree (AST) and convert it back to CSS with configurable formatting. Built with TypeScript for type safety and modern JavaScript features.
Install
npm install @adobe/css-tools
Usage
import { parse, stringify } from '@adobe/css-tools'
// Parse CSS to AST
const ast = parse('body { font-size: 12px; }')
// Stringify AST back to CSS
const css = stringify(ast)
// => "body { font-size: 12px; }"
// Pretty print with custom indentation
const formatted = stringify(ast, { indent: ' ' })
// => "body {\n font-size: 12px;\n}"
// Minify output
const minified = stringify(ast, { compress: true })
// => "body{font-size:12px}"
API
parse(code, options?)
Parses CSS code and returns an Abstract Syntax Tree (AST).
Parameters:
code(string) - The CSS code to parseoptions(object, optional) - Parsing optionssilent(boolean) - Silently fail on parse errors instead of throwingsource(string) - File path for better error reporting
Returns: CssStylesheetAST - The parsed CSS as an AST
stringify(ast, options?)
Converts a CSS AST back to CSS string with configurable formatting.
Parameters:
ast(CssStylesheetAST) - The CSS AST to stringifyoptions(object, optional) - Stringification optionsindent(string) - Indentation string (default:' ')compress(boolean) - Whether to compress/minify the output (default:false)
Returns: string - The formatted CSS string
Features
- Complete CSS Support: All standard CSS features including selectors, properties, values, at-rules, and comments
- TypeScript Support: Full type definitions for all AST nodes and functions
- Error Handling: Configurable error handling with detailed position information
- Formatting Options: Pretty print, minify, or custom formatting
- Performance Optimized: Efficient parsing and stringification for large CSS files
- Source Maps: Track original source positions for debugging and tooling
Supported CSS Features
- Selectors: Element, class, ID, attribute, pseudo-class, pseudo-element selectors
- Properties: All standard CSS properties and custom properties
- Values: Colors, lengths, percentages, functions, calc(), etc.
- At-rules: @media, @keyframes, @import, @charset, @namespace, @font-face, @page, @document, @supports, @container, @layer, @starting-style, @host, @custom-media
- Comments: Both / / and // comments
- Whitespace: Preserves formatting information
- Vendor prefixes: Supports vendor-prefixed at-rules and properties
- Nested rules: Media queries, supports, containers, etc.
- Complex selectors: Combinators, pseudo-selectors, attribute selectors
Examples
Error Handling
import { parse } from '@adobe/css-tools'
const malformedCss = `
body { color: red; }
{ color: blue; } /* Missing selector */
.valid { background: green; }
`
// Parse with silent error handling
const result = parse(malformedCss, { silent: true })
// Check for parsing errors
if (result.stylesheet.parsingErrors) {
console.log('Parsing errors:', result.stylesheet.parsingErrors.length)
result.stylesheet.parsingErrors.forEach(error => {
console.log(`Error at line ${error.line}: ${error.message}`)
})
}
// Valid rules are still parsed
console.log('Valid rules:', result.stylesheet.rules.length)
Source Tracking
import { parse } from '@adobe/css-tools'
const css = 'body { color: red; }'
const ast = parse(css, { source: 'styles.css' })
// Position information is available
const rule = ast.stylesheet.rules[0]
console.log(rule.position?.source) // "styles.css"
console.log(rule.position?.start) // { line: 1, column: 1 }
console.log(rule.position?.end) // { line: 1, column: 20 }
For more examples, see the Examples documentation.
Performance
The library is optimized for performance and can handle large CSS files efficiently. For benchmarking information, see the benchmark/ directory in the source code.
Documentation
- API Reference - Complete API documentation
- AST Structure - Detailed AST node types and structure
- Examples - Comprehensive usage examples
- Changelog - Version history and changes
Background
This is a fork of the npm css package, maintained by Adobe with modern improvements including TypeScript support, enhanced performance, and security updates. It provides a robust foundation for CSS tooling, preprocessing, and analysis.