react-saasify-chrisvxd/example/node_modules/htmlnano/lib/modules/minifyCss.js

React components for Saasify web clients.

'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.default = minifyCss;

var _helpers = require('../helpers');

var _cssnano = require('cssnano');

var _cssnano2 = _interopRequireDefault(_cssnano);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var postcssOptions = {
    // Prevent the following warning from being shown:
    // > Without `from` option PostCSS could generate wrong source map and will not find Browserslist config.
    // > Set it to CSS file path or to `undefined` to prevent this warning.
    from: undefined
};

/** Minify CSS with cssnano */
function minifyCss(tree, options, cssnanoOptions) {
    var promises = [];
    tree.walk(function (node) {
        if ((0, _helpers.isStyleNode)(node)) {
            promises.push(processStyleNode(node, cssnanoOptions));
        } else if (node.attrs && node.attrs.style) {
            promises.push(processStyleAttr(node, cssnanoOptions));
        }

        return node;
    });

    return Promise.all(promises).then(function () {
        return tree;
    });
}

function processStyleNode(styleNode, cssnanoOptions) {
    var css = (0, _helpers.extractCssFromStyleNode)(styleNode);
    return _cssnano2.default.process(css, postcssOptions, cssnanoOptions).then(function (result) {
        return styleNode.content = [result.css];
    });
}

function processStyleAttr(node, cssnanoOptions) {
    // CSS "color: red;" is invalid. Therefore it should be wrapped inside some selector:
    // a{color: red;}
    var wrapperStart = 'a{';
    var wrapperEnd = '}';
    var wrappedStyle = wrapperStart + (node.attrs.style || '') + wrapperEnd;

    return _cssnano2.default.process(wrappedStyle, postcssOptions, cssnanoOptions).then(function (result) {
        var minifiedCss = result.css;
        // Remove wrapperStart at the start and wrapperEnd at the end of minifiedCss
        node.attrs.style = minifiedCss.substring(wrapperStart.length, minifiedCss.length - wrapperEnd.length);
    });
}