autoprefixer.js

"use strict";

var browserslist = require('browserslist');

var postcss = require('postcss');

var agents = require('caniuse-lite').agents;

var Browsers = require('./browsers');

var Prefixes = require('./prefixes');

var data = require('../data/prefixes');

var info = require('./info');

function isPlainObject(obj) {
  return Object.prototype.toString.apply(obj) === '[object Object]';
}

var cache = {};

function timeCapsule(result, prefixes) {
  if (prefixes.browsers.selected.length === 0) {
    return;
  }

  if (prefixes.add.selectors.length > 0) {
    return;
  }

  if (Object.keys(prefixes.add).length > 2) {
    return;
  }
  /* istanbul ignore next */


  result.warn('Greetings, time traveller. ' + 'We are in the golden age of prefix-less CSS, ' + 'where Autoprefixer is no longer needed for your stylesheet.');
}

module.exports = postcss.plugin('autoprefixer', function () {
  for (var _len = arguments.length, reqs = new Array(_len), _key = 0; _key < _len; _key++) {
    reqs[_key] = arguments[_key];
  }

  var options;

  if (reqs.length === 1 && isPlainObject(reqs[0])) {
    options = reqs[0];
    reqs = undefined;
  } else if (reqs.length === 0 || reqs.length === 1 && !reqs[0]) {
    reqs = undefined;
  } else if (reqs.length <= 2 && (reqs[0] instanceof Array || !reqs[0])) {
    options = reqs[1];
    reqs = reqs[0];
  } else if (typeof reqs[reqs.length - 1] === 'object') {
    options = reqs.pop();
  }

  if (!options) {
    options = {};
  }

  if (options.browser) {
    throw new Error('Change `browser` option to `browsers` in Autoprefixer');
  } else if (options.browserslist) {
    throw new Error('Change `browserslist` option to `browsers` in Autoprefixer');
  }

  if (options.browsers) {
    reqs = options.browsers;
  }

  if (typeof options.grid === 'undefined') {
    options.grid = false;
  }

  var brwlstOpts = {
    ignoreUnknownVersions: options.ignoreUnknownVersions,
    stats: options.stats
  };

  function loadPrefixes(opts) {
    var d = module.exports.data;
    var browsers = new Browsers(d.browsers, reqs, opts, brwlstOpts);
    var key = browsers.selected.join(', ') + JSON.stringify(options);

    if (!cache[key]) {
      cache[key] = new Prefixes(d.prefixes, browsers, options);
    }

    return cache[key];
  }

  function plugin(css, result) {
    var prefixes = loadPrefixes({
      from: css.source && css.source.input.file,
      env: options.env
    });
    timeCapsule(result, prefixes);

    if (options.remove !== false) {
      prefixes.processor.remove(css, result);
    }

    if (options.add !== false) {
      prefixes.processor.add(css, result);
    }
  }

  plugin.options = options;
  plugin.browsers = reqs;

  plugin.info = function (opts) {
    opts = opts || {};
    opts.from = opts.from || process.cwd();
    return info(loadPrefixes(opts));
  };

  return plugin;
});
/**
 * Autoprefixer data
 */

module.exports.data = {
  browsers: agents,
  prefixes: data
  /**
   * Autoprefixer default browsers
   */

};
module.exports.defaults = browserslist.defaults;
/**
 * Inspect with default Autoprefixer
 */

module.exports.info = function () {
  return module.exports().info();
};