const fs = require('fs'); const cheerio = require('cheerio'); const { mergeWith, isArray } = require('lodash'); const { PurgeCSS } = require('purgecss'); const purgeHtml = require('purgecss-from-html'); const { cleanCSS } = require('./clean_css'); const { HTML_TO_REMOVE } = require('./constants'); const { die } = require('./utils'); const cleanHtml = (html) => { const $ = cheerio.load(html); HTML_TO_REMOVE.forEach((selector) => { $(selector).remove(); }); return $.html(); }; const mergePurgeCSSOptions = (...options) => mergeWith(...options, (objValue, srcValue) => { if (isArray(objValue)) { return objValue.concat(srcValue); } return undefined; }); const getStartupCSS = async ({ htmlPaths, cssPaths, purgeOptions }) => { const content = htmlPaths.map((htmlPath) => { if (!fs.existsSync(htmlPath)) { die(`Could not find fixture "${htmlPath}". Have you run the fixtures?`); } const rawHtml = fs.readFileSync(htmlPath); const html = cleanHtml(rawHtml); return { raw: html, extension: 'html' }; }); const purgeCSSResult = await new PurgeCSS().purge({ content, css: cssPaths, ...mergePurgeCSSOptions( { fontFace: true, variables: true, keyframes: true, blocklist: [/:hover/, /:focus/, /-webkit-/, /-moz-focusring-/, /-ms-expand/], safelist: { standard: ['brand-header-logo'], }, // By default, PurgeCSS ignores special characters, but our utilities use "!" defaultExtractor: (x) => x.match(/[\w-!]+/g), extractors: [ { extractor: purgeHtml, extensions: ['html'], }, ], }, purgeOptions, ), }); return purgeCSSResult.map(({ css }) => cleanCSS(css)).join('\n'); }; module.exports = { getStartupCSS };