media-query-parser

This package's v3 (currently in beta) involves a complete overhaul from v2 to a more sustainable shape. See v2 API docs instead

• Create a JS object from a CSS media queries
• Create a CSS media query from a JS object
• Returns a ParserError for invalid CSS media queries
• Spec-compliant - https://www.w3.org/TR/mediaqueries-5/
  • All valid queries parsed; e.g. (100px < width < 200px)
• Zero-dependencies
• Well tested
• TypeScript friendly

This repo/package contains only the parser, stringify and isParserError.

media-query-fns uses this library internally to achieve common use-cases.

You can try it out!

Install

This package is available from the npm registry.

npm install media-query-parser

Usage

Supports JavaScript + TypeScript:

import { parseMediaQuery } from "media-query-parser";

const mediaQuery = parseMediaQuery("screen and (width <= 768px)");
if (!isParserError(mediaQuery)) {
  console.log(mediaQuery);
  // {
  //   type: "query",
  //   mediaType: "screen",
  //   mediaCondition: {
  //     type: "condition",
  //     children: [
  //       {
  //         type: "feature",
  //         feature: "width",
  //         context: "range",
  //         range: {
  //           featureName: "width",
  //           rightOp: "<=",
  //           rightToken: {
  //             type: "dimension",
  //             value: 768,
  //             unit: "px",
  //             flag: "number"
  //           },
  //         },
  //       },
  //     ],
  //   },
  // }
  console.log(stringify(mediaQuery.mediaCondition.children[0]));
  // "(width <= 768px)"
}

Can also be imported via require("media-query-parser").

Considerations & Caveats

This library does:

• follow the spec's CSS syntax / media query parsing rules
• remove extra layers from unnecessary parentheses (((((max-width: 768px)))))
• handle unusual whitespace anywhere that the spec allows it

This library will not:

• sanity check the actual media features or their types beyond the parser rules; so (max-power: infinite) is as valid as (min-width: 768px)
• support calc() or var() - functions are disallowed by the spec, even though some browsers seem to support them. If/when the spec allows them they'll be added in a new major version

Contributing

• PRs welcome and accepted, simply fork and create
• Issues also very welcome
• Treat others with common courtesy and respect 🤝

Dev environment (for contributing) requires:

• node >= 16.14.0
• npm >= 6.8.0
• git >= 2.11

Licence

MIT