rollup-plugin-less/dist/rollup-plugin-less.mjs

import _regeneratorRuntime from 'babel-runtime/regenerator';
import _JSON$stringify from 'babel-runtime/core-js/json/stringify';
import _asyncToGenerator from 'babel-runtime/helpers/asyncToGenerator';
import fs from 'fs-extra';
import 'path';
import less from 'less';
import { createFilter } from 'rollup-pluginutils';

/*
 * create a style tag and append to head tag
 * @params {String} css style
 */

function insertStyle(css) {
    if (!css) return;

    if (typeof window == 'undefined') return;
    var style = document.createElement('style');
    style.setAttribute('media', 'screen');

    style.innerHTML = css;
    document.head.appendChild(style);
    return css;
}

var renderSync = function renderSync(code, option) {
    return less.render(code, option).then(function (output) {
        return output.css;
    }, function (error) {
        throw error;
    });
};

var fileCount = 0;

function plugin() {
    var options = arguments.length <= 0 || arguments[0] === undefined ? { insert: false } : arguments[0];

    var filter = rollupPluginutils.createFilter(options.include || ['**/*.less', '**/*.css'], options.exclude || 'node_modules/**');

    var injectFnName = '__$styleInject';
    return {
        name: 'less',
        intro: function intro() {
            return insertStyle.toString().replace(/insertStyle/, injectFnName);
        },
        transform: function transform(code, id) {
            var _this = this;

            return _asyncToGenerator(_regeneratorRuntime.mark(function _callee() {
                var css, exportCode;
                return _regeneratorRuntime.wrap(function _callee$(_context) {
                    while (1) {
                        switch (_context.prev = _context.next) {
                            case 0:
                                if (filter(id)) {
                                    _context.next = 2;
                                    break;
                                }

                                return _context.abrupt('return', null);

                            case 2:
                                fileCount++;

                                _context.prev = 3;

                                options.option = options.option || {};
                                options.option['filename'] = id;
                                options.output = options.output || 'rollup.build.css';

                                _context.next = 9;
                                return renderSync(code, options.option);

                            case 9:
                                css = _context.sent;

                                if (!(options.output && isFunc(options.output))) {
                                    _context.next = 14;
                                    break;
                                }

                                _context.next = 13;
                                return options.output(css, id);

                            case 13:
                                css = _context.sent;

                            case 14:

                                if (options.output && isString(options.output)) {
                                    if (fileCount == 1) {
                                        //clean the output file
                                        fs.removeSync(options.output);
                                    }
                                    fs.appendFileSync(options.output, css);
                                }

                                exportCode = '';


                                if (options.insert != false) {
                                    exportCode = 'export default ' + injectFnName + '(' + _JSON$stringify(css.toString()) + ');';
                                } else {
                                    exportCode = 'export default ' + _JSON$stringify(css.toString()) + ';';
                                }
                                return _context.abrupt('return', {
                                    code: exportCode,
                                    map: { mappings: '' }
                                });

                            case 20:
                                _context.prev = 20;
                                _context.t0 = _context['catch'](3);
                                throw _context.t0;

                            case 23:
                            case 'end':
                                return _context.stop();
                        }
                    }
                }, _callee, _this, [[3, 20]]);
            }))();
        }
    };
};

function isString(str) {
    if (typeof str == 'string') {
        return true;
    } else {
        return false;
    }
}

function isFunc(fn) {
    if (typeof fn == 'function') {
        return true;
    } else {
        return false;
    }
}

export default plugin;