mirror of
https://github.com/GoogleChromeLabs/squoosh.git
synced 2025-11-11 16:26:20 +00:00
Jason Miller
GitHub
322
config/critters-webpack-plugin.js
Normal file
322
config/critters-webpack-plugin.js
Normal file
@@ -0,0 +1,322 @@
|
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const fs = require('fs');
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const { promisify } = require('util');
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const path = require('path');
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const parse5 = require('parse5');
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const nwmatcher = require('nwmatcher');
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const css = require('css');
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const prettyBytes = require('pretty-bytes');
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||||
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const readFile = promisify(fs.readFile);
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const treeAdapter = parse5.treeAdapters.htmlparser2;
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const PLUGIN_NAME = 'critters-webpack-plugin';
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const PARSE5_OPTS = {
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treeAdapter
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};
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/** Critters: Webpack Plugin Edition!
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* @class
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* @param {Object} options
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* @param {Boolean} [options.external=true] Fetch and inline critical styles from external stylesheets
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* @param {Boolean} [options.async=false] Convert critical-inlined external stylesheets to load asynchronously (via link rel="preload" - see https://filamentgroup.com/lab/async-css.html)
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* @param {Boolean} [options.preload=false] (requires `async` option) Append a new <link rel="stylesheet"> into <body> instead of swapping the preload's rel attribute
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* @param {Boolean} [options.compress=true] Compress resulting critical CSS
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*/
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module.exports = class CrittersWebpackPlugin {
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constructor (options) {
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this.options = options || {};
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this.urlFilter = this.options.filter;
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if (this.urlFilter instanceof RegExp) {
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this.urlFilter = this.urlFilter.test.bind(this.urlFilter);
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}
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}
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/** Invoked by Webpack during plugin initialization */
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apply (compiler) {
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const outputPath = compiler.options.output.path;
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// hook into the compiler to get a Compilation instance...
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compiler.hooks.compilation.tap(PLUGIN_NAME, compilation => {
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// ... which is how we get an "after" hook into html-webpack-plugin's HTML generation.
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compilation.hooks.htmlWebpackPluginAfterHtmlProcessing.tapAsync(PLUGIN_NAME, (htmlPluginData, callback) => {
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// Parse the generated HTML in a DOM we can mutate
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const document = parse5.parse(htmlPluginData.html, PARSE5_OPTS);
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makeDomInteractive(document);
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let externalStylesProcessed = Promise.resolve();
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// `external:false` skips processing of external sheets
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if (this.options.external !== false) {
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const externalSheets = document.querySelectorAll('link[rel="stylesheet"]');
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externalStylesProcessed = Promise.all(externalSheets.map(
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link => this.embedLinkedStylesheet(link, compilation, outputPath)
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));
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}
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externalStylesProcessed
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.then(() => {
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// go through all the style tags in the document and reduce them to only critical CSS
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const styles = document.querySelectorAll('style');
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return Promise.all(styles.map(style => this.processStyle(style, document)));
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})
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.then(() => {
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// serialize the document back to HTML and we're done
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const html = parse5.serialize(document, PARSE5_OPTS);
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callback(null, { html });
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})
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.catch(callback);
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});
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});
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}
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/** Inline the target stylesheet referred to by a <link rel="stylesheet"> (assuming it passes `options.filter`) */
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embedLinkedStylesheet (link, compilation, outputPath) {
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const href = link.getAttribute('href');
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const document = link.ownerDocument;
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// skip filtered resources, or network resources if no filter is provided
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if (this.urlFilter ? this.urlFilter(href) : href.match(/^(https?:)?\/\//)) return Promise.resolve();
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// path on disk
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const filename = path.resolve(outputPath, href.replace(/^\//, ''));
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// try to find a matching asset by filename in webpack's output (not yet written to disk)
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const asset = compilation.assets[path.relative(outputPath, filename).replace(/^\.\//, '')];
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// wait for a disk read if we had to go to disk
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const promise = asset ? Promise.resolve(asset.source()) : readFile(filename, 'utf8');
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return promise.then(sheet => {
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// the reduced critical CSS gets injected into a new <style> tag
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const style = document.createElement('style');
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style.appendChild(document.createTextNode(sheet));
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link.parentNode.insertBefore(style, link.nextSibling);
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// drop a reference to the original URL onto the tag (used for reporting to console later)
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style.$$name = href;
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// the `async` option changes any critical'd <link rel="stylesheet"> tags to async-loaded equivalents
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if (this.options.async) {
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link.setAttribute('rel', 'preload');
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link.setAttribute('as', 'style');
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if (this.options.preload) {
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const bodyLink = document.createElement('link');
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bodyLink.setAttribute('rel', 'stylesheet');
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bodyLink.setAttribute('href', href);
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document.body.appendChild(bodyLink);
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} else {
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link.setAttribute('onload', "this.rel='stylesheet'");
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}
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}
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});
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}
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/** Parse the stylesheet within a <style> element, then reduce it to contain only rules used by the document. */
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processStyle (style) {
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const done = Promise.resolve();
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const document = style.ownerDocument;
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// basically `.textContent`
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let sheet = style.childNodes.length > 0 && style.childNodes.map(node => node.nodeValue).join('\n');
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// store a reference to the previous serialized stylesheet for reporting stats
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const before = sheet;
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// Skip empty stylesheets
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if (!sheet) return done;
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const ast = css.parse(sheet);
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// Walk all CSS rules, transforming unused rules to comments (which get removed)
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visit(ast, rule => {
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if (rule.type === 'rule') {
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// Filter the selector list down to only those matche
|
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rule.selectors = rule.selectors.filter(sel => {
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// Strip pseudo-elements and pseudo-classes, since we only care that their associated elements exist.
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// This means any selector for a pseudo-element or having a pseudo-class will be inlined if the rest of the selector matches.
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sel = sel.replace(/::?(?:[a-z-]+)([.[#~&^:*]|\s|\n|$)/gi, '$1');
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return document.querySelector(sel, document) != null;
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});
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// If there are no matched selectors, remove the rule:
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if (rule.selectors.length === 0) {
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return false;
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}
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}
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// If there are no remaining rules, remove the whole rule.
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return !rule.rules || rule.rules.length !== 0;
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});
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sheet = css.stringify(ast, { compress: this.options.compress !== false });
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return done.then(() => {
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// If all rules were removed, get rid of the style element entirely
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if (sheet.trim().length === 0) {
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sheet.parentNode.removeChild(sheet);
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} else {
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// replace the inline stylesheet with its critical'd counterpart
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while (style.lastChild) {
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style.removeChild(style.lastChild);
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}
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style.appendChild(document.createTextNode(sheet));
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}
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// output some stats
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const name = style.$$name ? style.$$name.replace(/^\//, '') : 'inline CSS';
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const percent = (before.length - sheet.length) / before.length * 100 | 0;
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console.log('\u001b[32mCritters: inlined ' + prettyBytes(sheet.length) + ' (' + percent + '% of original ' + prettyBytes(before.length) + ') of ' + name + '.\u001b[39m');
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});
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}
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};
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/** Recursively walk all rules in a stylesheet.
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* The iterator can explicitly return `false` to remove the current node.
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*/
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function visit (node, fn) {
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if (node.stylesheet) return visit(node.stylesheet, fn);
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node.rules = node.rules.filter(rule => {
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if (rule.rules) {
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visit(rule, fn);
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}
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return fn(rule) !== false;
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});
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}
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/** Enhance an htmlparser2-style DOM with basic manipulation methods. */
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function makeDomInteractive (document) {
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defineProperties(document, DocumentExtensions);
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// Find the first <html> element within the document
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// document.documentElement = document.childNodes.filter( child => String(child.tagName).toLowerCase()==='html' )[0];
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// Extend Element.prototype with DOM manipulation methods.
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// Note: document.$$scratchElement is also used by createTextNode()
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const scratch = document.$$scratchElement = document.createElement('div');
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const elementProto = Object.getPrototypeOf(scratch);
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defineProperties(elementProto, ElementExtensions);
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elementProto.ownerDocument = document;
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// nwmatcher is a selector engine that happens to work with Parse5's htmlparser2 DOM (they form the base of jsdom).
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// It is exposed to the document so that it can be used within Element.prototype methods.
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document.$match = nwmatcher({ document });
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document.$match.configure({
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CACHING: false,
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USE_QSAPI: false,
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USE_HTML5: false
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});
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}
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/** Essentially Object.defineProperties() except any functions are assigned as values rather than descriptors. */
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function defineProperties (obj, properties) {
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for (const i in properties) {
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const value = properties[i];
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Object.defineProperty(obj, i, typeof value === 'function' ? { value } : value);
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}
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}
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/** {document,Element}.getElementsByTagName() is the only traversal method required by nwmatcher.
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* Note: if perf issues arise, 2 faster but more verbose implementations are benchmarked here:
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* https://esbench.com/bench/5ac3b647f2949800a0f619e1
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*/
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function getElementsByTagName (tagName) {
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// Only return Element/Document nodes
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if ((this.nodeType !== 1 && this.nodeType !== 9) || this.type === 'directive') return [];
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return Array.prototype.concat.apply(
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// Add current element if it matches tag
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(tagName === '*' || (this.tagName && (this.tagName === tagName || this.nodeName === tagName.toUpperCase()))) ? [this] : [],
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// Check children recursively
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this.children.map(child => getElementsByTagName.call(child, tagName))
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);
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}
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/** Methods and descriptors to mix into Element.prototype */
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const ElementExtensions = {
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nodeName: {
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get () {
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return this.tagName.toUpperCase();
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}
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},
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insertBefore (child, referenceNode) {
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if (!referenceNode) return this.appendChild(child);
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treeAdapter.insertBefore(this, child, referenceNode);
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return child;
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},
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appendChild (child) {
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treeAdapter.appendChild(this, child);
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return child;
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},
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removeChild (child) {
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treeAdapter.detachNode(child);
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},
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setAttribute (name, value) {
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if (this.attribs == null) this.attribs = {};
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if (value == null) value = '';
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this.attribs[name] = value;
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},
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removeAttribute (name) {
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if (this.attribs != null) {
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||||
delete this.attribs[name];
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||||
}
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||||
},
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||||
getAttribute (name) {
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||||
return this.attribs != null && this.attribs[name];
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||||
},
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||||
hasAttribute (name) {
|
||||
return this.attribs != null && this.attribs[name] != null;
|
||||
},
|
||||
getAttributeNode (name) {
|
||||
const value = this.getAttribute(name);
|
||||
if (value != null) return { specified: true, value };
|
||||
},
|
||||
getElementsByTagName
|
||||
};
|
||||
|
||||
/** Methods and descriptors to mix into the global document instance */
|
||||
const DocumentExtensions = {
|
||||
// document is just an Element in htmlparser2, giving it a nodeType of ELEMENT_NODE.
|
||||
// nwmatcher requires that it at least report a correct nodeType of DOCUMENT_NODE.
|
||||
nodeType: {
|
||||
get () {
|
||||
return 9;
|
||||
}
|
||||
},
|
||||
nodeName: {
|
||||
get () {
|
||||
return '#document';
|
||||
}
|
||||
},
|
||||
documentElement: {
|
||||
get () {
|
||||
// Find the first <html> element within the document
|
||||
return this.childNodes.filter(child => String(child.tagName).toLowerCase() === 'html')[0];
|
||||
}
|
||||
},
|
||||
body: {
|
||||
get () {
|
||||
return this.querySelector('body');
|
||||
}
|
||||
},
|
||||
createElement (name) {
|
||||
return treeAdapter.createElement(name, null, []);
|
||||
},
|
||||
createTextNode (text) {
|
||||
// there is no dedicated createTextNode equivalent in htmlparser2's DOM, so
|
||||
// we have to insert Text and then remove and return the resulting Text node.
|
||||
const scratch = this.$$scratchElement;
|
||||
treeAdapter.insertText(scratch, text);
|
||||
const node = scratch.lastChild;
|
||||
treeAdapter.detachNode(node);
|
||||
return node;
|
||||
},
|
||||
querySelector (sel) {
|
||||
return this.$match.first(sel, this.documentElement);
|
||||
},
|
||||
querySelectorAll (sel) {
|
||||
return this.$match.select(sel, this.documentElement);
|
||||
},
|
||||
getElementsByTagName,
|
||||
// nwmatcher uses inexistence of `document.addEventListener` to detect IE:
|
||||
// https://github.com/dperini/nwmatcher/blob/3edb471e12ce7f7d46dc1606c7f659ff45675a29/src/nwmatcher.js#L353
|
||||
addEventListener: Object
|
||||
};
|
||||
23
package.json
23
package.json
@@ -9,13 +9,20 @@
|
||||
"lint": "eslint src"
|
||||
},
|
||||
"eslintConfig": {
|
||||
"extends": "eslint-config-developit",
|
||||
"extends": [
|
||||
"standard",
|
||||
"standard-jsx"
|
||||
],
|
||||
"rules": {
|
||||
"indent": [
|
||||
2,
|
||||
2
|
||||
],
|
||||
"react/prefer-stateless-function": 0
|
||||
"semi": [
|
||||
2,
|
||||
"always"
|
||||
],
|
||||
"prefer-const": 1
|
||||
}
|
||||
},
|
||||
"eslintIgnore": [
|
||||
@@ -34,12 +41,20 @@
|
||||
"babel-plugin-transform-react-remove-prop-types": "^0.4.13",
|
||||
"babel-preset-env": "^1.6.1",
|
||||
"babel-register": "^6.26.0",
|
||||
"chalk": "^2.3.2",
|
||||
"clean-webpack-plugin": "^0.1.19",
|
||||
"copy-webpack-plugin": "^4.5.1",
|
||||
"css": "^2.2.1",
|
||||
"css-loader": "^0.28.11",
|
||||
"ejs-loader": "^0.3.1",
|
||||
"eslint": "^4.18.2",
|
||||
"eslint-config-developit": "^1.1.1",
|
||||
"eslint-config-standard": "^11.0.0",
|
||||
"eslint-config-standard-jsx": "^5.0.0",
|
||||
"eslint-plugin-import": "^2.10.0",
|
||||
"eslint-plugin-node": "^6.0.1",
|
||||
"eslint-plugin-promise": "^3.7.0",
|
||||
"eslint-plugin-react": "^7.7.0",
|
||||
"eslint-plugin-standard": "^3.0.1",
|
||||
"extract-text-webpack-plugin": "^4.0.0-beta.0",
|
||||
"fork-ts-checker-notifier-webpack-plugin": "^0.4.0",
|
||||
"fork-ts-checker-webpack-plugin": "^0.4.1",
|
||||
@@ -48,6 +63,8 @@
|
||||
"jsdom": "^11.6.2",
|
||||
"mini-css-extract-plugin": "^0.3.0",
|
||||
"node-sass": "^4.7.2",
|
||||
"nwmatcher": "^1.4.4",
|
||||
"parse5": "^4.0.0",
|
||||
"preact-render-to-string": "^3.7.0",
|
||||
"preload-webpack-plugin": "github:GoogleChromeLabs/preload-webpack-plugin",
|
||||
"progress-bar-webpack-plugin": "^1.11.0",
|
||||
|
||||
@@ -1,16 +1,23 @@
|
||||
<!DOCTYPE html>
|
||||
<html lang="en">
|
||||
<head>
|
||||
<meta charset="utf-8">
|
||||
<title>Squoosh</title>
|
||||
<meta name="viewport" content="width=device-width,initial-scale=1">
|
||||
<meta name="mobile-web-app-capable" content="yes">
|
||||
<meta name="apple-mobile-web-app-capable" content="yes">
|
||||
<meta name="theme-color" content="#673ab8">
|
||||
<link rel="manifest" href="/manifest.json">
|
||||
</head>
|
||||
<body>
|
||||
<div id="app" prerender></div>
|
||||
<!-- <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons" /> -->
|
||||
</body>
|
||||
<head>
|
||||
<meta charset="utf-8">
|
||||
<title>Squoosh</title>
|
||||
<meta name="viewport" content="width=device-width,initial-scale=1">
|
||||
<meta name="mobile-web-app-capable" content="yes">
|
||||
<meta name="apple-mobile-web-app-capable" content="yes">
|
||||
<meta name="theme-color" content="#673ab8">
|
||||
<link rel="manifest" href="/manifest.json">
|
||||
</head>
|
||||
<body>
|
||||
<div id="app" prerender></div>
|
||||
<script>
|
||||
(function(style){
|
||||
style.rel='stylesheet'
|
||||
style.href='https://fonts.googleapis.com/icon?family=Material+Icons'
|
||||
document.head.appendChild(style)
|
||||
})(document.createElement('link'));
|
||||
</script>
|
||||
<!-- <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons" /> -->
|
||||
</body>
|
||||
</html>
|
||||
@@ -3,17 +3,17 @@ import { options } from 'preact';
|
||||
const classNameDescriptor = {
|
||||
enumerable: false,
|
||||
configurable: true,
|
||||
get() {
|
||||
get () {
|
||||
return this.class;
|
||||
},
|
||||
set(value) {
|
||||
set (value) {
|
||||
this.class = value;
|
||||
}
|
||||
};
|
||||
|
||||
let old = options.vnode;
|
||||
const old = options.vnode;
|
||||
options.vnode = vnode => {
|
||||
let a = vnode.attributes;
|
||||
const a = vnode.attributes;
|
||||
if (a != null) {
|
||||
if ('className' in a) {
|
||||
a.class = a.className;
|
||||
|
||||
@@ -1,7 +1,7 @@
|
||||
// @import './material-icons.scss';
|
||||
// @import 'material-components-web/material-components-web';
|
||||
@import './reset.scss';
|
||||
@import url('https://fonts.googleapis.com/icon?family=Material+Icons');
|
||||
// @import url('https://fonts.googleapis.com/icon?family=Material+Icons');
|
||||
|
||||
html, body {
|
||||
height: 100%;
|
||||
|
||||
@@ -9,6 +9,7 @@ const PreloadWebpackPlugin = require('preload-webpack-plugin');
|
||||
const ReplacePlugin = require('webpack-plugin-replace');
|
||||
const CopyPlugin = require('copy-webpack-plugin');
|
||||
const WorkboxPlugin = require('workbox-webpack-plugin');
|
||||
const CrittersPlugin = require('./config/critters-webpack-plugin');
|
||||
const WatchTimestampsPlugin = require('./config/watch-timestamps-plugin');
|
||||
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
|
||||
|
||||
@@ -175,6 +176,13 @@ module.exports = function(_, env) {
|
||||
// Inject <link rel="preload"> for resources
|
||||
isProd && new PreloadWebpackPlugin(),
|
||||
|
||||
isProd && new CrittersPlugin({
|
||||
// convert critical'd <link rel="stylesheet"> to <link rel="preload" as="style">:
|
||||
async: true,
|
||||
// copy original <link rel="stylesheet"> to the end of <body>:
|
||||
preload: true
|
||||
}),
|
||||
|
||||
// Inline constants during build, so they can be folded by UglifyJS.
|
||||
new webpack.DefinePlugin({
|
||||
// We set node.process=false later in this config.
|
||||
|
||||
Reference in New Issue
Block a user