stylelint/lib/utils/isAutoprefixable.js

A mighty, modern CSS linter.

/* @flow */
'use strict';

const autoprefixer = require('autoprefixer');
const Browsers = require('autoprefixer/lib/browsers');
const Prefixes = require('autoprefixer/lib/prefixes');

/**
 * Use Autoprefixer's secret powers to determine whether or
 * not a certain CSS identifier contains a vendor prefix that
 * Autoprefixer, given the standardized identifier, could add itself.
 *
 * Used by `*-no-vendor-prefix-*` rules to find superfluous
 * vendor prefixes.
 */

const prefixes = new Prefixes(
	autoprefixer.data.prefixes,
	new Browsers(autoprefixer.data.browsers, []),
);

/**
 * Most identifier types have to be looked up in a unique way,
 * so we're exposing special functions for each.
 */
module.exports = {
	atRuleName(identifier /*: string*/) /*: boolean*/ {
		return prefixes.remove[`@${identifier.toLowerCase()}`];
	},

	selector(identifier /*: string*/) /*: boolean*/ {
		return prefixes.remove.selectors.some((selectorObj) => {
			return identifier.toLowerCase() === selectorObj.prefixed;
		});
	},

	mediaFeatureName(identifier /*: string*/) /*: boolean*/ {
		return identifier.toLowerCase().indexOf('device-pixel-ratio') !== -1;
	},

	property(identifier /*: string*/) /*: boolean*/ {
		return autoprefixer.data.prefixes[prefixes.unprefixed(identifier.toLowerCase())];
	},

	propertyValue(prop /*: string*/, value /*: string*/) /*: boolean*/ {
		const possiblePrefixableValues =
			prefixes.remove[prop.toLowerCase()] && prefixes.remove[prop.toLowerCase()].values;

		return (
			possiblePrefixableValues &&
			possiblePrefixableValues.some((valueObj) => {
				return value.toLowerCase() === valueObj.prefixed;
			})
		);
	},
};