616 lines
21 KiB
TypeScript
616 lines
21 KiB
TypeScript
import { Rule } from 'postcss';
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import { ChildNode } from 'domhandler';
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/**
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* Copyright 2018 Google LLC
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not
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* use this file except in compliance with the License. You may obtain a copy of
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* the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations under
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* the License.
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*/
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type SplitIterator<T> = (item: T, index: number, a: T[], b?: T[]) => boolean;
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declare function filterSelectors(this: Rule, predicate: SplitIterator<string>): void;
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declare module 'postcss' {
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interface Node {
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_other?: Rule;
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$$remove?: boolean;
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$$markedSelectors?: string[];
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filterSelectors?: typeof filterSelectors;
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}
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}
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/**
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* Copyright 2018 Google LLC
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not
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* use this file except in compliance with the License. You may obtain a copy of
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* the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations under
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* the License.
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*/
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declare module 'domhandler' {
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interface Node {
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nodeName: string;
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id: string;
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className: string;
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insertBefore: (child: ChildNode, referenceNode: ChildNode | null) => ChildNode;
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appendChild: (child: ChildNode) => ChildNode;
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removeChild: (child: ChildNode) => void;
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remove: () => void;
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textContent: string;
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setAttribute: (name: string, value: string) => void;
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removeAttribute: (name: string) => void;
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getAttribute: (name: string) => string;
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hasAttribute: (name: string) => boolean;
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getAttributeNode: (name: string) => undefined | {
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specified: true;
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value: string;
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};
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exists: (sel: string) => boolean;
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querySelector: (sel: string) => Node;
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querySelectorAll: (sel: string) => Node[];
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$$external?: boolean;
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$$name?: string;
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$$reduce?: boolean;
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$$links?: ChildNode[];
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}
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}
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declare class Beasties {
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#selectorCache = /* @__PURE__ */ new Map();
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options;
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logger;
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fs;
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constructor(options = {}) {
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this.options = Object.assign({
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logLevel: "info",
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path: "",
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publicPath: "",
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reduceInlineStyles: true,
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pruneSource: false,
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additionalStylesheets: [],
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allowRules: []
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}, options);
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this.logger = this.options.logger || createLogger(this.options.logLevel);
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}
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/**
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* Read the contents of a file from the specified filesystem or disk
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*/
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readFile(filename) {
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const fs = this.fs;
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return new Promise((resolve, reject) => {
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const callback = (err, data) => {
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if (err)
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reject(err);
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else resolve(data.toString());
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};
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if (fs && fs.readFile) {
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fs.readFile(filename, callback);
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} else {
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readFile(filename, "utf-8", callback);
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}
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});
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}
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/**
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* Write content to a file
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*/
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writeFile(filename, data) {
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const fs = this.fs;
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return new Promise((resolve, reject) => {
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const callback = (err) => {
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if (err)
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reject(err);
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else resolve();
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};
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if (fs && fs.writeFile) {
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fs.writeFile(filename, data, callback);
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} else {
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writeFile(filename, data, callback);
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}
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});
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}
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/**
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* Apply critical CSS processing to the html
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*/
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async process(html) {
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const start = Date.now();
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const document = createDocument(html);
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if (this.options.additionalStylesheets.length > 0) {
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await this.embedAdditionalStylesheet(document);
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}
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if (this.options.external !== false) {
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const externalSheets = [...document.querySelectorAll('link[rel="stylesheet"]')];
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const hasCustomEmbed = this.embedLinkedStylesheet !== Beasties.prototype.embedLinkedStylesheet;
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if (hasCustomEmbed) {
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for (const link of externalSheets) {
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await this.embedLinkedStylesheet(link, document);
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}
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} else {
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const sheets = await Promise.all(
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externalSheets.map((link) => this.fetchStylesheet(link, document))
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);
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for (const sheet of sheets) {
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if (sheet) {
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this.embedFetchedStylesheet(sheet, document);
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}
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}
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}
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}
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const styles = this.getAffectedStyleTags(document);
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for (const style of styles) {
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this.processStyle(style, document);
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}
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if (this.options.mergeStylesheets !== false && styles.length !== 0) {
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this.mergeStylesheets(document);
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}
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const output = serializeDocument(document);
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const end = Date.now();
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this.logger.info?.(`Time ${end - start}ms`);
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return output;
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}
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/**
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* Get the style tags that need processing
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*/
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getAffectedStyleTags(document) {
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const styles = [...document.querySelectorAll("style")];
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if (this.options.reduceInlineStyles === false) {
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return styles.filter((style) => style.$$external);
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}
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return styles;
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}
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mergeStylesheets(document) {
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const styles = this.getAffectedStyleTags(document);
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if (styles.length === 0) {
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this.logger.warn?.(
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"Merging inline stylesheets into a single <style> tag skipped, no inline stylesheets to merge"
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);
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return;
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}
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const first = styles[0];
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let sheet = first.textContent;
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for (let i = 1; i < styles.length; i++) {
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const node = styles[i];
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sheet += node.textContent;
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node.remove();
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}
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first.textContent = sheet;
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}
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/**
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* Given href, find the corresponding CSS asset
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*/
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async getCssAsset(href, _style) {
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const outputPath = this.options.path;
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const publicPath = this.options.publicPath;
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let normalizedPath = href.replace(/^\/(?!\/)|[?#].*$/g, "");
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const pathPrefix = `${(publicPath || "").replace(/(^\/(?!\/)|\/$)/g, "")}/`;
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if (normalizedPath.startsWith(pathPrefix) && !(pathPrefix === "/" && normalizedPath.startsWith("//"))) {
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normalizedPath = normalizedPath.substring(pathPrefix.length).replace(/^\//, "");
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}
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const isRemote = /^https?:\/\//.test(normalizedPath) || normalizedPath.startsWith("//");
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if (isRemote) {
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if (this.options.remote === true) {
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try {
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const absoluteUrl = href.startsWith("//") ? `https:${href}` : href;
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const response = await fetch(absoluteUrl);
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if (!response.ok) {
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this.logger.warn?.(`Failed to fetch ${absoluteUrl} (${response.status})`);
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return void 0;
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}
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return await response.text();
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} catch (error) {
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this.logger.warn?.(`Error fetching ${href}: ${error.message}`);
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return void 0;
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}
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}
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return void 0;
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}
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const filename = path.resolve(outputPath, normalizedPath);
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if (!isSubpath(outputPath, filename)) {
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return void 0;
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}
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let sheet;
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try {
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sheet = await this.readFile(filename);
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} catch {
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this.logger.warn?.(`Unable to locate stylesheet: ${filename}`);
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}
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return sheet;
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}
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checkInlineThreshold(link, style, sheet) {
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if (this.options.inlineThreshold && sheet.length < this.options.inlineThreshold) {
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const href = style.$$name;
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style.$$reduce = false;
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this.logger.info?.(
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`\x1B[32mInlined all of ${href} (${sheet.length} was below the threshold of ${this.options.inlineThreshold})\x1B[39m`
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);
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link.remove();
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return true;
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}
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return false;
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}
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/**
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* Inline the stylesheets from options.additionalStylesheets (assuming it passes `options.filter`)
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*/
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async embedAdditionalStylesheet(document) {
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const styleSheetsIncluded = [];
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const sources = await Promise.all(
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this.options.additionalStylesheets.map((cssFile) => {
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if (styleSheetsIncluded.includes(cssFile)) {
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return [];
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}
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styleSheetsIncluded.push(cssFile);
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const style = document.createElement("style");
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style.$$external = true;
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style.$$name = cssFile;
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return this.getCssAsset(cssFile, style).then((sheet) => [sheet, style]);
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})
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);
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for (const [sheet, style] of sources) {
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if (sheet) {
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style.textContent = sheet;
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document.head.appendChild(style);
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}
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}
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}
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/**
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* Fetch CSS content for a linked stylesheet
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*/
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async fetchStylesheet(link, document) {
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const href = link.getAttribute("href");
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const pathname = href?.split("?")[0]?.split("#")[0];
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if (!pathname?.endsWith(".css")) {
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return void 0;
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}
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const style = document.createElement("style");
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style.$$external = true;
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const sheet = await this.getCssAsset(href, style);
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if (!sheet) {
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return void 0;
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}
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return { link, href, sheet, style };
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}
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/**
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* Embed a fetched stylesheet into the document
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*/
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embedFetchedStylesheet(data, document) {
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const { link, href, sheet, style } = data;
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style.textContent = sheet;
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style.$$name = href;
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style.$$links = [link];
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link.parentNode?.insertBefore(style, link);
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if (this.checkInlineThreshold(link, style, sheet)) {
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return;
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}
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let media = link.getAttribute("media");
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if (media && !validateMediaQuery(media)) {
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media = void 0;
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}
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const preloadMode = this.options.preload;
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let cssLoaderPreamble = "function $loadcss(u,m,l){(l=document.createElement('link')).rel='stylesheet';l.href=u;document.head.appendChild(l)}";
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const lazy = preloadMode === "js-lazy";
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if (lazy) {
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cssLoaderPreamble = cssLoaderPreamble.replace(
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"l.href",
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"l.media='print';l.onload=function(){l.media=m};l.href"
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);
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}
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if (preloadMode === false)
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return;
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let noscriptFallback = false;
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let updateLinkToPreload = false;
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const noscriptLink = link.cloneNode(false);
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if (preloadMode === "body") {
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document.body.appendChild(link);
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} else {
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if (preloadMode === "js" || preloadMode === "js-lazy") {
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const script = document.createElement("script");
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script.setAttribute("data-href", href);
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script.setAttribute("data-media", media || "all");
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const js = `${cssLoaderPreamble}$loadcss(document.currentScript.dataset.href,document.currentScript.dataset.media)`;
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script.textContent = js;
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link.parentNode.insertBefore(script, link.nextSibling);
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style.$$links.push(script);
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cssLoaderPreamble = "";
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noscriptFallback = true;
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updateLinkToPreload = true;
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} else if (preloadMode === "media") {
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link.setAttribute("media", "print");
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link.setAttribute("onload", `this.media='${media || "all"}'`);
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noscriptFallback = true;
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} else if (preloadMode === "swap-high") {
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link.setAttribute("rel", "alternate stylesheet preload");
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link.setAttribute("title", "styles");
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link.setAttribute("as", "style");
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link.setAttribute("onload", `this.title='';this.rel='stylesheet'`);
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noscriptFallback = true;
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} else if (preloadMode === "swap-low") {
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link.setAttribute("rel", "alternate stylesheet");
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link.setAttribute("title", "styles");
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link.setAttribute("onload", `this.title='';this.rel='stylesheet'`);
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noscriptFallback = true;
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} else if (preloadMode === "swap") {
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link.setAttribute("onload", "this.rel='stylesheet'");
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updateLinkToPreload = true;
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noscriptFallback = true;
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} else {
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const bodyLink = link.cloneNode(false);
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bodyLink.removeAttribute("id");
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document.body.appendChild(bodyLink);
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style.$$links.push(bodyLink);
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updateLinkToPreload = true;
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}
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}
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if (this.options.noscriptFallback !== false && noscriptFallback && !href.includes("</noscript>")) {
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const noscript = document.createElement("noscript");
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noscriptLink.removeAttribute("id");
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noscript.appendChild(noscriptLink);
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link.parentNode.insertBefore(noscript, link.nextSibling);
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style.$$links.push(noscript);
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}
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if (updateLinkToPreload) {
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link.setAttribute("rel", "preload");
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link.setAttribute("as", "style");
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}
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}
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/**
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* Inline the target stylesheet referred to by a <link rel="stylesheet"> (assuming it passes `options.filter`)
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*/
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async embedLinkedStylesheet(link, document) {
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const sheet = await this.fetchStylesheet(link, document);
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if (sheet) {
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this.embedFetchedStylesheet(sheet, document);
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}
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}
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/**
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* Prune the source CSS files
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*/
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pruneSource(style, before, sheetInverse) {
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const minSize = this.options.minimumExternalSize;
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const name = style.$$name;
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const shouldInline = minSize && sheetInverse.length < minSize;
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if (shouldInline) {
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this.logger.info?.(
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`\x1B[32mInlined all of ${name} (non-critical external stylesheet would have been ${sheetInverse.length}b, which was below the threshold of ${minSize})\x1B[39m`
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);
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}
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if (shouldInline || !sheetInverse) {
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style.textContent = before;
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if (style.$$links) {
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for (const link of style.$$links) {
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const parent = link.parentNode;
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parent?.removeChild(link);
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}
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}
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}
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return !!shouldInline;
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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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*/
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processStyle(style, document) {
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if (style.$$reduce === false)
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return;
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const name = style.$$name ? style.$$name.replace(/^\//, "") : "inline CSS";
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const options = this.options;
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const beastiesContainer = document.beastiesContainer;
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let keyframesMode = options.keyframes ?? "critical";
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if (keyframesMode === true)
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keyframesMode = "all";
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if (keyframesMode === false)
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keyframesMode = "none";
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let sheet = style.textContent;
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const before = sheet;
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if (!sheet)
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return;
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const ast = parseStylesheet(sheet, { safeParser: this.options.safeParser !== false });
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const astInverse = options.pruneSource ? parseStylesheet(sheet, { safeParser: this.options.safeParser !== false }) : null;
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let criticalFonts = "";
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const failedSelectors = [];
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const criticalKeyframeNames = /* @__PURE__ */ new Set();
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let includeNext = false;
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let includeAll = false;
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let excludeNext = false;
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let excludeAll = false;
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const shouldPreloadFonts = options.fonts === true || options.preloadFonts === true;
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const shouldInlineFonts = options.fonts !== false && options.inlineFonts === true;
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walkStyleRules(
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ast,
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markOnly((rule) => {
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if (rule.type === "comment") {
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const beastiesComment = rule.text.match(/^(?<!! )beasties:(.*)/);
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const command = beastiesComment && beastiesComment[1];
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if (command) {
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switch (command) {
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case "include":
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includeNext = true;
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break;
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case "exclude":
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excludeNext = true;
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break;
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case "include start":
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includeAll = true;
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break;
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case "include end":
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includeAll = false;
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break;
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case "exclude start":
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excludeAll = true;
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break;
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case "exclude end":
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excludeAll = false;
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break;
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}
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}
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}
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if (rule.type === "rule") {
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if (includeNext) {
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includeNext = false;
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return true;
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}
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if (excludeNext) {
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excludeNext = false;
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return false;
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}
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if (includeAll) {
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return true;
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}
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if (excludeAll) {
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return false;
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}
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rule.filterSelectors?.((sel) => {
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const isAllowedRule = options.allowRules.some((exp) => {
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if (exp instanceof RegExp) {
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return exp.test(sel);
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}
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return exp === sel;
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});
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if (isAllowedRule)
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return true;
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if (sel === ":root" || sel === "html" || sel === "body" || sel[0] === ":" && /^::?(?:before|after)$/.test(sel)) {
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return true;
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}
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sel = this.normalizeCssSelector(sel);
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if (!sel)
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return false;
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try {
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return beastiesContainer.exists(sel);
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} catch (e) {
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failedSelectors.push(`${sel} -> ${e.message || e.toString()}`);
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return false;
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}
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});
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if (!rule.selector) {
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return false;
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}
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if (rule.nodes) {
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for (const decl of rule.nodes) {
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if (!("prop" in decl)) {
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continue;
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}
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if (shouldInlineFonts && /\bfont(?:-family)?\b/i.test(decl.prop)) {
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criticalFonts += ` ${decl.value}`;
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}
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if (decl.prop === "animation" || decl.prop === "animation-name") {
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for (const name2 of decl.value.split(/\s+/)) {
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const nameTrimmed = name2.trim();
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if (nameTrimmed)
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criticalKeyframeNames.add(nameTrimmed);
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}
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}
|
|
}
|
|
}
|
|
}
|
|
if (rule.type === "atrule" && (rule.name === "font-face" || rule.name === "layer"))
|
|
return;
|
|
const hasRemainingRules = ("nodes" in rule && rule.nodes?.some((rule2) => !rule2.$$remove)) ?? true;
|
|
return hasRemainingRules;
|
|
})
|
|
);
|
|
if (failedSelectors.length !== 0) {
|
|
this.logger.warn?.(
|
|
`${failedSelectors.length} rules skipped due to selector errors:
|
|
${failedSelectors.join("\n ")}`
|
|
);
|
|
}
|
|
const preloadedFonts = /* @__PURE__ */ new Set();
|
|
walkStyleRulesWithReverseMirror(ast, astInverse, (rule) => {
|
|
if (rule.$$remove === true)
|
|
return false;
|
|
if ("selectors" in rule) {
|
|
applyMarkedSelectors(rule);
|
|
}
|
|
if (rule.type === "atrule" && rule.name === "keyframes") {
|
|
if (keyframesMode === "none")
|
|
return false;
|
|
if (keyframesMode === "all")
|
|
return true;
|
|
return criticalKeyframeNames.has(rule.params);
|
|
}
|
|
if (rule.type === "atrule" && rule.name === "font-face") {
|
|
let family, src;
|
|
if (rule.nodes) {
|
|
for (const decl of rule.nodes) {
|
|
if (!("prop" in decl)) {
|
|
continue;
|
|
}
|
|
if (decl.prop === "src") {
|
|
src = (decl.value.match(/url\s*\(\s*(['"]?)(.+?)\1\s*\)/) || [])[2];
|
|
} else if (decl.prop === "font-family") {
|
|
family = decl.value;
|
|
}
|
|
}
|
|
if (src && shouldPreloadFonts && !preloadedFonts.has(src)) {
|
|
preloadedFonts.add(src);
|
|
const preload = document.createElement("link");
|
|
preload.setAttribute("rel", "preload");
|
|
preload.setAttribute("as", "font");
|
|
preload.setAttribute("crossorigin", "anonymous");
|
|
preload.setAttribute("href", src.trim());
|
|
document.head.appendChild(preload);
|
|
}
|
|
}
|
|
if (!shouldInlineFonts || !family || !src || !criticalFonts.includes(family)) {
|
|
return false;
|
|
}
|
|
}
|
|
});
|
|
sheet = serializeStylesheet(ast, {
|
|
compress: this.options.compress !== false
|
|
});
|
|
if (sheet.trim().length === 0) {
|
|
if (style.parentNode) {
|
|
style.remove();
|
|
}
|
|
return;
|
|
}
|
|
let afterText = "";
|
|
let styleInlinedCompletely = false;
|
|
if (options.pruneSource) {
|
|
const sheetInverse = serializeStylesheet(astInverse, {
|
|
compress: this.options.compress !== false
|
|
});
|
|
styleInlinedCompletely = this.pruneSource(style, before, sheetInverse);
|
|
if (styleInlinedCompletely) {
|
|
const percent2 = sheetInverse.length / before.length * 100;
|
|
afterText = `, reducing non-inlined size ${percent2 | 0}% to ${formatSize(sheetInverse.length)}`;
|
|
}
|
|
const cssFilePath = path.resolve(this.options.path, name);
|
|
this.writeFile(cssFilePath, sheetInverse).then(() => this.logger.info?.(`${name} was successfully updated`)).catch((err) => this.logger.error?.(err));
|
|
}
|
|
if (!styleInlinedCompletely) {
|
|
style.textContent = sheet;
|
|
}
|
|
const percent = sheet.length / before.length * 100 | 0;
|
|
this.logger.info?.(
|
|
`\x1B[32mInlined ${formatSize(sheet.length)} (${percent}% of original ${formatSize(before.length)}) of ${name}${afterText}.\x1B[39m`
|
|
);
|
|
}
|
|
normalizeCssSelector(sel) {
|
|
let normalizedSelector = this.#selectorCache.get(sel);
|
|
if (normalizedSelector !== void 0) {
|
|
return normalizedSelector;
|
|
}
|
|
normalizedSelector = sel.replace(removePseudoClassesAndElementsPattern, "").replace(removeTrailingCommasPattern, (match) => match.includes("(") ? "(" : ")").replace(implicitUniversalPattern, "$1 * $2").replace(emptyCombinatorPattern, "$1 *").trim();
|
|
this.#selectorCache.set(sel, normalizedSelector);
|
|
return normalizedSelector;
|
|
}
|
|
}
|
|
|
|
export = Beasties;
|