From a09490913ef71a269792f9caaedb49b513949233 Mon Sep 17 00:00:00 2001 From: Jason Miller Date: Wed, 30 May 2018 14:04:07 -0400 Subject: [PATCH] Initial release! --- .editorconfig | 9 + .gitignore | 3 + CONTRIBUTING.md | 28 ++ LICENSE | 202 +++++++++++++ README.md | 270 ++++++++++++++++++ package.json | 97 +++++++ src/index.js | 247 ++++++++++++++++ src/util.js | 62 ++++ test/__snapshots__/index.test.js.snap | 48 ++++ test/_helpers.js | 70 +++++ test/fixtures/basic/dist/bundle.js | 1 + test/fixtures/basic/dist/index.html | 5 + test/fixtures/basic/index.html | 8 + test/fixtures/basic/index.js | 3 + test/fixtures/factory/dist/bundle.js | 1 + test/fixtures/factory/dist/index.html | 5 + test/fixtures/factory/index.html | 8 + test/fixtures/factory/index.js | 1 + test/fixtures/failure/index.html | 8 + test/fixtures/failure/index.js | 1 + .../function-export-dom/dist/bundle.js | 1 + .../function-export-dom/dist/index.html | 5 + test/fixtures/function-export-dom/index.html | 8 + test/fixtures/function-export-dom/index.js | 9 + test/fixtures/named-export-fn/dist/bundle.js | 1 + test/fixtures/named-export-fn/dist/index.html | 5 + test/fixtures/named-export-fn/index.html | 8 + test/fixtures/named-export-fn/index.js | 3 + test/fixtures/value-export/dist/bundle.js | 1 + test/fixtures/value-export/dist/index.html | 5 + test/fixtures/value-export/index.html | 8 + test/fixtures/value-export/index.js | 1 + test/fixtures/with-field/dist/bundle.js | 1 + test/fixtures/with-field/dist/index.html | 8 + test/fixtures/with-field/index.html | 11 + test/fixtures/with-field/index.js | 1 + test/index.test.js | 135 +++++++++ 37 files changed, 1288 insertions(+) create mode 100644 .editorconfig create mode 100644 .gitignore create mode 100644 CONTRIBUTING.md create mode 100644 LICENSE create mode 100644 README.md create mode 100644 package.json create mode 100644 src/index.js create mode 100644 src/util.js create mode 100644 test/__snapshots__/index.test.js.snap create mode 100644 test/_helpers.js create mode 100644 test/fixtures/basic/dist/bundle.js create mode 100644 test/fixtures/basic/dist/index.html create mode 100644 test/fixtures/basic/index.html create mode 100644 test/fixtures/basic/index.js create mode 100644 test/fixtures/factory/dist/bundle.js create mode 100644 test/fixtures/factory/dist/index.html create mode 100644 test/fixtures/factory/index.html create mode 100644 test/fixtures/factory/index.js create mode 100644 test/fixtures/failure/index.html create mode 100644 test/fixtures/failure/index.js create mode 100644 test/fixtures/function-export-dom/dist/bundle.js create mode 100644 test/fixtures/function-export-dom/dist/index.html create mode 100644 test/fixtures/function-export-dom/index.html create mode 100644 test/fixtures/function-export-dom/index.js create mode 100644 test/fixtures/named-export-fn/dist/bundle.js create mode 100644 test/fixtures/named-export-fn/dist/index.html create mode 100644 test/fixtures/named-export-fn/index.html create mode 100644 test/fixtures/named-export-fn/index.js create mode 100644 test/fixtures/value-export/dist/bundle.js create mode 100644 test/fixtures/value-export/dist/index.html create mode 100644 test/fixtures/value-export/index.html create mode 100644 test/fixtures/value-export/index.js create mode 100644 test/fixtures/with-field/dist/bundle.js create mode 100644 test/fixtures/with-field/dist/index.html create mode 100644 test/fixtures/with-field/index.html create mode 100644 test/fixtures/with-field/index.js create mode 100644 test/index.test.js diff --git a/.editorconfig b/.editorconfig new file mode 100644 index 0000000..c6c8b36 --- /dev/null +++ b/.editorconfig @@ -0,0 +1,9 @@ +root = true + +[*] +indent_style = space +indent_size = 2 +end_of_line = lf +charset = utf-8 +trim_trailing_whitespace = true +insert_final_newline = true diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..24ca935 --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +/node_modules +/dist +/package-lock.json diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md new file mode 100644 index 0000000..bb70059 --- /dev/null +++ b/CONTRIBUTING.md @@ -0,0 +1,28 @@ +# How to Contribute + +We'd love to accept your patches and contributions to this project. 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+ prerender-loader +

+ prerender-loader + npm +

+

+ +Painless universal prerendering for Webpack. Works great with +[html-webpack-plugin]. + +> 🧐 **What is Prerendering?** +> +>Pre-rendering describes the process of rendering a client-side application at +>build time, producing useful static HTML that can be sent to the browser +>instead of an empty bootstrapping page. +> +>Pre-rendering is like Server-Side Rendering, just done at build time to produce +>static files. Both techniques help get meaningful content onto the user's +>screen faster. + +## Features + +- Works entirely within Webpack +- Integrates with [html-webpack-plugin] +- Works with `webpack-dev-server` / `webpack serve` +- Supports both DOM and String prerendering +- Asynchronous rendering via async/await or Promises + +--- + + + +- [Features](#features) +- [How does it work?](#how-does-it-work) +- [Installation](#installation) +- [Usage](#usage) + - [DOM Prerendering](#dom-prerendering) + - [String Prerendering](#string-prerendering) + - [Injecting content into the HTML](#injecting-content-into-the-html) + - [Prerendering JavaScript Files](#prerendering-javascript-files) +- [Options](#options) +- [License](#license) + + + +## How does it work? + +`prerender-loader` renders your web application within Webpack during builds, +producing static HTML. When the loader is applied to an HTML file, it creates a +DOM structure from that HTML, compiles the application, runs it within the DOM +and serializes the result back to HTML. + +--- + +## Installation + +First, install `prerender-loader` as a development dependency: + +```sh +npm i -D prerender-loader +``` + +--- + +## Usage + +In most cases, you'll want to apply the loader to your `html-webpack-plugin` +template option: + +```diff +// webpack.config.js +module.exports = { + plugins: [ + new HtmlWebpackPlugin({ +- template: 'index.html', ++ template: '!!prerender-loader?string!index.html', + + // any other options you'd normally set are still supported: + compile: false, + inject: true + }) + ] +} +``` + +What does all that punctuation mean? Let's breaking the whole loader string +down: + +> In Webpack, a module identifier beginning with `!!` will bypass any configured +>loaders from `module.rules` - here we're saying "don't do anything to +>`index.html` except what I've defined here +> +>The `?string` parameter tells `prerender-loader` to output an ES module +>exporting the prerendered HTML string, rather than returning the HTML directly. +> +>Finally, everything up to the last `!` in a module identifier is the inline +>loader definition (the transforms to apply to a given module). The filename of +>the module to load comes after the `!`. +> +>**Note:** If you've already set up `html-loader` or `raw-loader` to handle +>`.html` files, you can skip both options and simply pass a `template` value of +>`"prerender-loader!index.html"`! + +As with any loader, it is also possible to apply `prerender-loader` on-the-fly +: + +```js +const html = require('prerender-loader?!./app.html'); +``` + +... or in your Webpack configuration's `module.rules` section: + +```js +module.exports = { + module: { + rules: [ + { + test: 'src/index.html', + loader: 'prerender-loader?string' + } + ] + } +} +``` + + +Once you have `prerender-loader` in-place, prerendering is now turned on. During +your build, the app will be executed, with any modifications it makes to +`index.html` will be saved to disk. This is fine for the needs of many apps, +but you can also take more explicit control over your prerendering: either using +the DOM or by rendering to a String. + +### DOM Prerendering + +During prerendering, your application gets compiled and run directly under +NodeJS, but within a [JSDOM] container so that you can use the familiar browser +globals like `document` and `window`. + +Here's an example `entry` module that uses DOM prerendering: + +```js +import { render } from 'fancy-dom-library'; +import App from './app'; + +export default () => { + render(, document.body); +}; +``` + +In all cases, asynchronous functions and callbacks are supported: + +```js +import { mount } from 'other-fancy-library'; +import app from './app'; + +export default async function prerender() { + let res = await fetch('https://example.com'); + let data = await res.json(); + mount(app(data), document.getElementById('app')); +} +``` + +### String Prerendering + +It's also possible to export a function from your Webpack entry module, which +gives you full control over prerendering: `prerender-loader` will call the +function and its return value will be used as the static HTML. If the exported +function returns a Promise, it will be awaited and the resolved value will be +used. + +```js +import { renderToString } from 'react-dom'; +import App from './app'; + +export default () => { + const html = renderToString(); + // returned HTML will be injected into : + return html; +}; +``` + +In addition to DOM and String prerendering, it's also possible to use a +combination of the two. If an application's Webpack entry exports a prerender +function that doens't return a value, the default DOM serialization will kick +in, just like in DOM prerendering. This means you can use your exported +prerender function to trigger DOM manipulation ("client-side" rendering), and +then just let `prerender-loader` handle generating the static HTML for whatever +got rendered. + +Here's an example that renders a [Preact] application and waits for DOM +rendering to settle down before allowing prerender-loader to serialize the +document to static HTML: + +```js +import { h, options } from 'preact'; +import { renderToString } from 'preact'; +import App from './app'; + +// we're done when there are no renders for 50ms: +const IDLE_TIMEOUT = 50; + +export default () => new Promise(resolve => { + let timer; + // each time preact re-renders, reset our idle timer: + options.debounceRendering = commit => { + clearTimeout(timer); + timer = setTimeout(resolve, IDLE_TIMEOUT); + commit(); + }; + + // render into using normal client-side rendering: + render(, document.body); +}); +``` + +### Injecting content into the HTML + +When applied to a `.html` file, `prerender-loader` will inject prerendered +content at the end of `` by default. If you want to place the content +somewhere else, you can add a `{{prerender}}` field: + +```html + + +
+ + {{prerender}} +
+ + +``` + +This works well if you intend to provide a prerender function that only returns +your application's HTML structure, not the full document's HTML. + +### Prerendering JavaScript Files + +In addition to processing `.html` files, the loader can also directly pre-render +`.js` scripts. The only difference is that the DOM used for prerender will be +initially empty: + +```js +const prerenderedHtml = require('!prerender-loader?string!./app.js'); +``` + +--- + +## Options + +All options are ... optional. + +| Option | Type | Default | Description | +|------------|---------|---------|-------------| +| `string` | boolean | false | Output a JS module exporting an HTML String instead of the HTML itself +| `disabled` | boolean | false | Bypass the loader entirely (but still respect `options.string`) +| `params` | object | null | Options to pass to your prerender function + + +--- + +## License + +[Apache 2.0](LICENSE) + +This is not an official Google product. + +[html-webpack-plugin]: https://github.com/jantimon/html-webpack-plugin +[JSDOM]: https://github.com/jsdom/jsdom +[Preact]: https://preactjs.com diff --git a/package.json b/package.json new file mode 100644 index 0000000..4a4979d --- /dev/null +++ b/package.json @@ -0,0 +1,97 @@ +{ + "name": "prerender-loader", + "version": "1.0.0", + "description": "Webpack plugin to inline critical CSS and lazy-load the rest.", + "main": "dist/prerender-loader.js", + "source": "src/index.js", + "license": "Apache-2.0", + "author": "The Chromium Authors", + "contributors": [ + { + "name": "Jason Miller", + "email": "developit@google.com" + } + ], + "keywords": [ + "pre-render", + "prerendering", + "webpack plugin", + "SSR", + "performance", + "first contentful paint", + "FCP" + ], + "repository": "GoogleChromeLabs/prerender-loader", + "scripts": { + "build": "microbundle -f cjs --no-compress --external all", + "docs": "documentation readme -q --no-markdown-toc -a public -s Usage --sort-order alpha src", + "test": "jest --coverage" + }, + "babel": { + "presets": [ + "env" + ] + }, + "jest": { + "testEnvironment": "node", + "coverageReporters": [ + "text" + ], + "collectCoverageFrom": [ + "src/**/*" + ], + "watchPathIgnorePatterns": [ + "node_modules", + "dist" + ] + }, + "devDependencies": { + "babel-core": "^6.26.3", + "babel-jest": "^23.0.0", + "babel-preset-env": "^1.7.0", + "documentation": "^7.0.0", + "eslint": "^4.19.1", + "eslint-config-standard": "^11.0.0", + "eslint-plugin-import": "^2.12.0", + "eslint-plugin-jest": "^21.15.2", + "eslint-plugin-node": "^6.0.1", + "eslint-plugin-promise": "^3.8.0", + "eslint-plugin-standard": "^3.1.0", + "file-loader": "^1.1.11", + "html-webpack-plugin": "^3.2.0", + "jest": "^23.0.0", + "memory-fs": "^0.4.1", + "microbundle": "^0.4.4", + "raw-loader": "^0.5.1", + "webpack": "^4.8.3" + }, + "dependencies": { + "jsdom": "^11.11.0", + "loader-utils": "^1.1.0" + }, + "peerDependencies": { + "webpack": "*", + "memory-fs": "*" + }, + "eslintConfig": { + "extends": [ + "standard", + "plugin:jest/recommended" + ], + "env": { + "browser": false, + "node": true + }, + "rules": { + "indent": [ + 2, + 2 + ], + "semi": [ + 2, + "always" + ], + "prefer-const": 1 + } + } +} diff --git a/src/index.js b/src/index.js new file mode 100644 index 0000000..7df7ad5 --- /dev/null +++ b/src/index.js @@ -0,0 +1,247 @@ +/** + * Copyright 2018 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not + * use this file except in compliance with the License. You may obtain a copy of + * the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + */ + +import os from 'os'; +import path from 'path'; +import jsdom from 'jsdom'; +import loaderUtils from 'loader-utils'; +import LibraryTemplatePlugin from 'webpack/lib/LibraryTemplatePlugin'; +import NodeTemplatePlugin from 'webpack/lib/node/NodeTemplatePlugin'; +import NodeTargetPlugin from 'webpack/lib/node/NodeTargetPlugin'; +import SingleEntryPlugin from 'webpack/lib/SingleEntryPlugin'; +import { DefinePlugin } from 'webpack'; +import MemoryFs from 'memory-fs'; +import { runChildCompiler, getRootCompiler, getBestModuleExport, stringToModule } from './util'; + +// Used to annotate this plugin's hooks in Tappable invocations +const PLUGIN_NAME = 'prerender-loader'; + +// Internal name used for the output bundle (never written to disk) +const FILENAME = 'ssr-bundle.js'; + +// Searches for fields of the form {{prerender}} or {{prerender:./some/module}} +const PRERENDER_REG = /\{\{prerender(?::\s*([^}]+?)\s*)?\}\}/; + +/** + * prerender-loader can be applied to any HTML or JS file with the given options. + * @public + * @param {Options} options Options to control how Critters inlines CSS. + * + * @example + * // webpack.config.js + * module.exports = { + * plugins: [ + * new HtmlWebpackPlugin({ + * // `!!` tells webpack to skip any configured loaders for .html files + * // `?string` tells prerender-loader output a JS module exporting the HTML string + * template: '!!prerender-loader?string!index.html' + * }) + * ] + * } + * + * @example + * // inline demo: assumes you have html-loader set up: + * import prerenderedHtml from '!prerender-loader!./file.html'; + */ +export default function PrerenderLoader (content) { + const options = loaderUtils.getOptions(this) || {}; + const outputFilter = options.as === 'string' || options.string ? stringToModule : String; + + if (options.disabled === true) { + return outputFilter(content); + } + + // When applied to HTML, attempts to inject into a specified {{prerender}} field. + // @note: this is only used when the entry module exports a String or function + // that resolves to a String, otherwise the whole document is serialized. + let inject = false; + if (!this.request.match(/.(js|ts)x?$/i)) { + const matches = content.match(PRERENDER_REG); + if (matches) { + inject = true; + options.entry = matches[1]; + } + options.templateContent = content; + } + + const callback = this.async(); + + prerender(this._compilation, this.request, options, inject, this) + .then(output => { + callback(null, outputFilter(output)); + }) + .catch(err => { + // console.error(err); + callback(err); + }); +} + +async function prerender (parentCompilation, request, options, inject, loader) { + const parentCompiler = getRootCompiler(parentCompilation.compiler); + const context = parentCompiler.options.context || process.cwd(); + const entry = './' + ((options.entry && [].concat(options.entry).pop().trim()) || path.relative(context, parentCompiler.options.entry)); + + const outputOptions = { + // fix: some plugins ignore/bypass outputfilesystem, so use a temp directory and ignore any writes. + path: os.tmpdir(), + filename: FILENAME + }; + + // Only copy over mini-extract-text-plugin (excluding it breaks extraction entirely) + const plugins = (parentCompiler.options.plugins || []).filter(c => /MiniCssExtractPlugin/i.test(c.constructor.name)); + + // Compile to an in-memory filesystem since we just want the resulting bundled code as a string + const compiler = parentCompilation.createChildCompiler('prerender', outputOptions, plugins); + compiler.context = parentCompiler.context; + compiler.outputFileSystem = new MemoryFs(); + + // Define PRERENDER to be true within the SSR bundle + new DefinePlugin({ + PRERENDER: 'true' + }).apply(compiler); + + // ... then define PRERENDER to be false within the client bundle + new DefinePlugin({ + PRERENDER: 'false' + }).apply(parentCompiler); + + // Compile to CommonJS to be executed by Node + new NodeTemplatePlugin(outputOptions).apply(compiler); + new NodeTargetPlugin().apply(compiler); + + new LibraryTemplatePlugin('PRERENDER_RESULT', 'var').apply(compiler); + + // Kick off compilation at our entry module (either the parent compiler's entry or a custom one defined via `{{prerender:entry.js}}`) + new SingleEntryPlugin(context, entry, undefined).apply(compiler); + + // Set up cache inheritance for the child compiler + const subCache = 'subcache ' + request; + function addChildCache (compilation, data) { + if (compilation.cache) { + if (!compilation.cache[subCache]) compilation.cache[subCache] = {}; + compilation.cache = compilation.cache[subCache]; + } + } + if (compiler.hooks) { + compiler.hooks.compilation.tap(PLUGIN_NAME, addChildCache); + } else { + compiler.plugin('compilation', addChildCache); + } + + const compilation = await runChildCompiler(compiler); + let result; + let dom, window, injectParent, injectNextSibling; + + if (compilation.assets[compilation.options.output.filename]) { + // Get the compiled main bundle + const output = compilation.assets[compilation.options.output.filename].source(); + + // @TODO: provide a non-DOM option to allow turning off JSDOM entirely. + + const tpl = options.templateContent || ''; + dom = new jsdom.JSDOM(tpl.replace(PRERENDER_REG, '
'), { + // suppress console-proxied eval() errors, but keep console proxying + virtualConsole: new jsdom.VirtualConsole({ omitJSDOMErrors: false }).sendTo(console), + + // don't track source locations for performance reasons + includeNodeLocations: false, + + // don't allow inline event handlers & script tag exec + runScripts: 'outside-only' + }); + window = dom.window; + + // Find the placeholder node for injection & remove it + const injectPlaceholder = window.document.getElementById('PRERENDER_INJECT'); + if (injectPlaceholder) { + injectParent = injectPlaceholder.parentNode; + injectNextSibling = injectPlaceholder.nextSibling; + injectPlaceholder.remove(); + } + + // These are missing from JSDOM + let counter = 0; + window.requestAnimationFrame = () => ++counter; + window.cancelAnimationFrame = () => { }; + + // Inject a require shim + window.require = moduleId => { + const asset = compilation.assets[moduleId.replace(/^\.?\//g, '')]; + if (!asset) { + throw Error(`Error: Module not found. attempted require("${moduleId}")`); + } + const mod = { exports: {} }; + window.eval(`(function(exports, module, require){\n${asset.source()}\n})`)(mod.exports, mod, window.require); + return mod.exports; + }; + + // Invoke the SSR bundle within the JSDOM document and grab the exported/returned result + result = window.eval(output + '\nPRERENDER_RESULT'); + } + + // Deal with ES Module exports (just use the best guess): + if (result && typeof result === 'object') { + result = getBestModuleExport(result); + } + + if (typeof result === 'function') { + result = result(options.params || null); + } + + // The entry can export or return a Promise in order to perform fully async prerendering: + if (result && result.then) { + result = await result; + } + + // Returning or resolving to `null` / `undefined` defaults to serializing the whole document. + // Note: this pypasses `inject` because the document is already derived from the template. + if (result !== undefined && options.templateContent) { + const template = window.document.createElement('template'); + template.innerHTML = result || ''; + const content = template.content || template; + const parent = injectParent || window.document.body; + let child; + while ((child = content.firstChild)) { + parent.insertBefore(child, injectNextSibling || null); + } + } else if (inject) { + // Otherwise inject the prerendered HTML into the template + return options.templateContent.replace(PRERENDER_REG, result || ''); + } + + // dom.serialize() doesn't properly serialize HTML appended to document.body. + return dom.serialize(); + // return `${window.document.documentElement.outerHTML}`; + + // // Returning or resolving to `null` / `undefined` defaults to serializing the whole document. + // // Note: this pypasses `inject` because the document is already derived from the template. + // if (result == null && dom) { + // // result = dom.serialize(); + // } else if (inject) { + // // @TODO determine if this is really worthwhile/necessary for the string return case + // if (injectParent || options.templateContent) { + // console.log(injectParent.outerHTML); + // (injectParent || document.body).insertAdjacentHTML('beforeend', result || ''); + // // result = dom.serialize(); + // } else { + // // Otherwise inject the prerendered HTML into the template + // return options.templateContent.replace(PRERENDER_REG, result || ''); + // } + // } + + // return dom.serialize(); + // return result; +} diff --git a/src/util.js b/src/util.js new file mode 100644 index 0000000..5d0a3eb --- /dev/null +++ b/src/util.js @@ -0,0 +1,62 @@ +/** + * Copyright 2018 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not + * use this file except in compliance with the License. You may obtain a copy of + * the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + */ + +/** + * Promisified version of compiler.runAsChild() with error hoisting and isolated output/assets. + * (runAsChild() merges assets into the parent compilation, we don't want that) + */ +export function runChildCompiler (compiler) { + return new Promise((resolve, reject) => { + compiler.compile((err, compilation) => { + // still allow the parent compiler to track execution of the child: + compiler.parentCompilation.children.push(compilation); + if (err) return reject(err); + + // Bubble stat errors up and reject the Promise: + if (compilation.errors && compilation.errors.length) { + const errorDetails = compilation.errors.map(error => error.details).join('\n'); + return reject(Error('Child compilation failed:\n' + errorDetails)); + } + + resolve(compilation); + }); + }); +} + +/** Crawl up the compiler tree and return the outermost compiler instance */ +export function getRootCompiler (compiler) { + while (compiler.parentCompilation && compiler.parentCompilation.compiler) { + compiler = compiler.parentCompilation.compiler; + } + return compiler; +} + +/** Find the best possible export for an ES Module. Returns `undefined` for no exports. */ +export function getBestModuleExport (exports) { + if (exports.default) { + return exports.default; + } + for (const prop in exports) { + if (prop !== '__esModule') { + return exports[prop]; + } + } +} + +/** Wrap a String up into an ES Module that exports it */ +export function stringToModule (str) { + return 'export default ' + JSON.stringify(str); +} diff --git a/test/__snapshots__/index.test.js.snap b/test/__snapshots__/index.test.js.snap new file mode 100644 index 0000000..0e6853f --- /dev/null +++ b/test/__snapshots__/index.test.js.snap @@ -0,0 +1,48 @@ +// Jest Snapshot v1, https://goo.gl/fbAQLP + +exports[`prerender-loader!x.html Imperative DOM, no {{prerender}} field should return serialized HTML 1`] = ` +" +Basic Demo + + +
this counts as SSR
" +`; + +exports[`prerender-loader!x.html default export function, no {{prerender}} field should inject returned HTML into 1`] = ` +" +export factory returning HTML + + +
some returned HTML
" +`; + +exports[`prerender-loader!x.html default export function, with {{prerender}} field should inject returned HTML in place of {{prerender}} 1`] = ` +" +prerender field demo + + +
+
more returned HTML
+
+" +`; + +exports[`prerender-loader!x.html exported function with no return value should serialize the whole document 1`] = ` +" +function export with default DOM serialization + + +
content injected into the dom
" +`; + +exports[`webpack compilation smoke test (no prerendering) should compile 1`] = ` +" + + +Basic Demo + + + + +" +`; diff --git a/test/_helpers.js b/test/_helpers.js new file mode 100644 index 0000000..3388e09 --- /dev/null +++ b/test/_helpers.js @@ -0,0 +1,70 @@ +/** + * Copyright 2018 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not + * use this file except in compliance with the License. You may obtain a copy of + * the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + */ + +import { promisify } from 'util'; +import jsdom from 'jsdom'; +import fs from 'fs'; +import path from 'path'; +import webpack from 'webpack'; + +const DOMParser = new jsdom.JSDOM(``, { includeNodeLocations: false }).window.DOMParser; + +// parse a string into a JSDOM Document +export const parseDom = html => new DOMParser().parseFromString(html, 'text/html'); + +// returns a promise resolving to the contents of a file +export const readFile = file => promisify(fs.readFile)(path.resolve(__dirname, file), 'utf8'); + +// invoke webpack on a given entry module, optionally mutating the default configuration +export function compile (entry, configDecorator) { + return new Promise((resolve, reject) => { + const context = path.dirname(path.resolve(__dirname, entry)); + entry = path.basename(entry); + let config = { + context, + entry: path.resolve(context, entry), + output: { + path: path.resolve(__dirname, path.resolve(context, 'dist')), + filename: 'bundle.js', + chunkFilename: '[name].chunk.js' + }, + resolveLoader: { + modules: [path.resolve(__dirname, '../node_modules')] + }, + module: { + rules: [] + }, + plugins: [] + }; + if (configDecorator) { + config = configDecorator(config) || config; + } + webpack(config, (err, stats) => { + if (err) return reject(err); + const info = stats.toJson(); + if (stats.hasErrors()) return reject(info.errors.join('\n')); + resolve(info); + }); + }); +} + +// invoke webpack via compile(), injecting `html` and `document` properties into the webpack build info. +export async function compileToHtml (fixture, configDecorator, crittersOptions = {}) { + const info = await compile(`fixtures/${fixture}/index.js`, configDecorator); + info.html = await readFile(`fixtures/${fixture}/dist/index.html`); + info.document = parseDom(info.html); + return info; +} diff --git a/test/fixtures/basic/dist/bundle.js b/test/fixtures/basic/dist/bundle.js new file mode 100644 index 0000000..33a1d83 --- /dev/null +++ b/test/fixtures/basic/dist/bundle.js @@ -0,0 +1 @@ +!function(e){var t={};function n(r){if(t[r])return t[r].exports;var o=t[r]={i:r,l:!1,exports:{}};return e[r].call(o.exports,o,o.exports,n),o.l=!0,o.exports}n.m=e,n.c=t,n.d=function(e,t,r){n.o(e,t)||Object.defineProperty(e,t,{configurable:!1,enumerable:!0,get:r})},n.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},n.n=function(e){var t=e&&e.__esModule?function(){return e.default}:function(){return e};return n.d(t,"a",t),t},n.o=function(e,t){return Object.prototype.hasOwnProperty.call(e,t)},n.p="",n(n.s=0)}([function(e,t){var n=document.createElement("div");n.appendChild(document.createTextNode("this counts as SSR")),document.body.appendChild(n)}]); \ No newline at end of file diff --git a/test/fixtures/basic/dist/index.html b/test/fixtures/basic/dist/index.html new file mode 100644 index 0000000..47871f9 --- /dev/null +++ b/test/fixtures/basic/dist/index.html @@ -0,0 +1,5 @@ + +Basic Demo + + +
this counts as SSR
\ No newline at end of file diff --git a/test/fixtures/basic/index.html b/test/fixtures/basic/index.html new file mode 100644 index 0000000..45e9abe --- /dev/null +++ b/test/fixtures/basic/index.html @@ -0,0 +1,8 @@ + + + + Basic Demo + + + + diff --git a/test/fixtures/basic/index.js b/test/fixtures/basic/index.js new file mode 100644 index 0000000..2e1e3d3 --- /dev/null +++ b/test/fixtures/basic/index.js @@ -0,0 +1,3 @@ +var div = document.createElement('div'); +div.appendChild(document.createTextNode('this counts as SSR')); +document.body.appendChild(div); diff --git a/test/fixtures/factory/dist/bundle.js b/test/fixtures/factory/dist/bundle.js new file mode 100644 index 0000000..e990e8b --- /dev/null +++ b/test/fixtures/factory/dist/bundle.js @@ -0,0 +1 @@ +!function(e){var r={};function t(n){if(r[n])return r[n].exports;var o=r[n]={i:n,l:!1,exports:{}};return e[n].call(o.exports,o,o.exports,t),o.l=!0,o.exports}t.m=e,t.c=r,t.d=function(e,r,n){t.o(e,r)||Object.defineProperty(e,r,{configurable:!1,enumerable:!0,get:n})},t.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},t.n=function(e){var r=e&&e.__esModule?function(){return e.default}:function(){return e};return t.d(r,"a",r),r},t.o=function(e,r){return Object.prototype.hasOwnProperty.call(e,r)},t.p="",t(t.s=0)}([function(e,r,t){"use strict";t.r(r),r.default=(()=>"
some returned HTML
")}]); \ No newline at end of file diff --git a/test/fixtures/factory/dist/index.html b/test/fixtures/factory/dist/index.html new file mode 100644 index 0000000..67f5509 --- /dev/null +++ b/test/fixtures/factory/dist/index.html @@ -0,0 +1,5 @@ + +export factory returning HTML + + +
some returned HTML
\ No newline at end of file diff --git a/test/fixtures/factory/index.html b/test/fixtures/factory/index.html new file mode 100644 index 0000000..791aa9a --- /dev/null +++ b/test/fixtures/factory/index.html @@ -0,0 +1,8 @@ + + + + export factory returning HTML + + + + diff --git a/test/fixtures/factory/index.js b/test/fixtures/factory/index.js new file mode 100644 index 0000000..3e6a67d --- /dev/null +++ b/test/fixtures/factory/index.js @@ -0,0 +1 @@ +export default () => `
some returned HTML
`; diff --git a/test/fixtures/failure/index.html b/test/fixtures/failure/index.html new file mode 100644 index 0000000..f6e7990 --- /dev/null +++ b/test/fixtures/failure/index.html @@ -0,0 +1,8 @@ + + + + Failure Demo + + + + diff --git a/test/fixtures/failure/index.js b/test/fixtures/failure/index.js new file mode 100644 index 0000000..1efa30b --- /dev/null +++ b/test/fixtures/failure/index.js @@ -0,0 +1 @@ +export { default } from './does-not-exist'; diff --git a/test/fixtures/function-export-dom/dist/bundle.js b/test/fixtures/function-export-dom/dist/bundle.js new file mode 100644 index 0000000..86aa688 --- /dev/null +++ b/test/fixtures/function-export-dom/dist/bundle.js @@ -0,0 +1 @@ +!function(e){var t={};function n(r){if(t[r])return t[r].exports;var o=t[r]={i:r,l:!1,exports:{}};return e[r].call(o.exports,o,o.exports,n),o.l=!0,o.exports}n.m=e,n.c=t,n.d=function(e,t,r){n.o(e,t)||Object.defineProperty(e,t,{configurable:!1,enumerable:!0,get:r})},n.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},n.n=function(e){var t=e&&e.__esModule?function(){return e.default}:function(){return e};return n.d(t,"a",t),t},n.o=function(e,t){return Object.prototype.hasOwnProperty.call(e,t)},n.p="",n(n.s=0)}([function(e,t,n){"use strict";n.r(t),t.default=(()=>new Promise(e=>{var t=document.createElement("div");t.appendChild(document.createTextNode("content injected into the dom")),document.body.appendChild(t),setTimeout(()=>{e()},10)}))}]); \ No newline at end of file diff --git a/test/fixtures/function-export-dom/dist/index.html b/test/fixtures/function-export-dom/dist/index.html new file mode 100644 index 0000000..704919f --- /dev/null +++ b/test/fixtures/function-export-dom/dist/index.html @@ -0,0 +1,5 @@ + +function export with default DOM serialization + + +
content injected into the dom
\ No newline at end of file diff --git a/test/fixtures/function-export-dom/index.html b/test/fixtures/function-export-dom/index.html new file mode 100644 index 0000000..cf1ab03 --- /dev/null +++ b/test/fixtures/function-export-dom/index.html @@ -0,0 +1,8 @@ + + + + function export with default DOM serialization + + + + diff --git a/test/fixtures/function-export-dom/index.js b/test/fixtures/function-export-dom/index.js new file mode 100644 index 0000000..9651efc --- /dev/null +++ b/test/fixtures/function-export-dom/index.js @@ -0,0 +1,9 @@ +export default () => new Promise(resolve => { + var div = document.createElement('div'); + div.appendChild(document.createTextNode('content injected into the dom')); + document.body.appendChild(div); + + setTimeout(() => { + resolve(); + }, 10); +}); diff --git a/test/fixtures/named-export-fn/dist/bundle.js b/test/fixtures/named-export-fn/dist/bundle.js new file mode 100644 index 0000000..f88ebd3 --- /dev/null +++ b/test/fixtures/named-export-fn/dist/bundle.js @@ -0,0 +1 @@ +!function(e){var r={};function n(t){if(r[t])return r[t].exports;var o=r[t]={i:t,l:!1,exports:{}};return e[t].call(o.exports,o,o.exports,n),o.l=!0,o.exports}n.m=e,n.c=r,n.d=function(e,r,t){n.o(e,r)||Object.defineProperty(e,r,{configurable:!1,enumerable:!0,get:t})},n.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},n.n=function(e){var r=e&&e.__esModule?function(){return e.default}:function(){return e};return n.d(r,"a",r),r},n.o=function(e,r){return Object.prototype.hasOwnProperty.call(e,r)},n.p="",n(n.s=0)}([function(e,r,n){"use strict";function t(){return"
some HTML returned from prerender()
"}n.r(r),n.d(r,"prerender",function(){return t})}]); \ No newline at end of file diff --git a/test/fixtures/named-export-fn/dist/index.html b/test/fixtures/named-export-fn/dist/index.html new file mode 100644 index 0000000..eecda0a --- /dev/null +++ b/test/fixtures/named-export-fn/dist/index.html @@ -0,0 +1,5 @@ + +named export factory + + +
some HTML returned from prerender()
\ No newline at end of file diff --git a/test/fixtures/named-export-fn/index.html b/test/fixtures/named-export-fn/index.html new file mode 100644 index 0000000..e2cb338 --- /dev/null +++ b/test/fixtures/named-export-fn/index.html @@ -0,0 +1,8 @@ + + + + named export factory + + + + diff --git a/test/fixtures/named-export-fn/index.js b/test/fixtures/named-export-fn/index.js new file mode 100644 index 0000000..98dae02 --- /dev/null +++ b/test/fixtures/named-export-fn/index.js @@ -0,0 +1,3 @@ +export function prerender () { + return `
some HTML returned from prerender()
`; +} diff --git a/test/fixtures/value-export/dist/bundle.js b/test/fixtures/value-export/dist/bundle.js new file mode 100644 index 0000000..3985ac8 --- /dev/null +++ b/test/fixtures/value-export/dist/bundle.js @@ -0,0 +1 @@ +!function(e){var r={};function t(n){if(r[n])return r[n].exports;var o=r[n]={i:n,l:!1,exports:{}};return e[n].call(o.exports,o,o.exports,t),o.l=!0,o.exports}t.m=e,t.c=r,t.d=function(e,r,n){t.o(e,r)||Object.defineProperty(e,r,{configurable:!1,enumerable:!0,get:n})},t.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},t.n=function(e){var r=e&&e.__esModule?function(){return e.default}:function(){return e};return t.d(r,"a",r),r},t.o=function(e,r){return Object.prototype.hasOwnProperty.call(e,r)},t.p="",t(t.s=0)}([function(e,r,t){"use strict";t.r(r),t.d(r,"PRERENDERED_HTML",function(){return n});const n=Promise.resolve("
this is the resolved value of PRERENDERED_HTML
")}]); \ No newline at end of file diff --git a/test/fixtures/value-export/dist/index.html b/test/fixtures/value-export/dist/index.html new file mode 100644 index 0000000..553270d --- /dev/null +++ b/test/fixtures/value-export/dist/index.html @@ -0,0 +1,5 @@ + +value export + + +
this is the resolved value of PRERENDERED_HTML
\ No newline at end of file diff --git a/test/fixtures/value-export/index.html b/test/fixtures/value-export/index.html new file mode 100644 index 0000000..6087486 --- /dev/null +++ b/test/fixtures/value-export/index.html @@ -0,0 +1,8 @@ + + + + value export + + + + diff --git a/test/fixtures/value-export/index.js b/test/fixtures/value-export/index.js new file mode 100644 index 0000000..d2293fe --- /dev/null +++ b/test/fixtures/value-export/index.js @@ -0,0 +1 @@ +export const PRERENDERED_HTML = Promise.resolve(`
this is the resolved value of PRERENDERED_HTML
`); diff --git a/test/fixtures/with-field/dist/bundle.js b/test/fixtures/with-field/dist/bundle.js new file mode 100644 index 0000000..0b2b4aa --- /dev/null +++ b/test/fixtures/with-field/dist/bundle.js @@ -0,0 +1 @@ +!function(e){var r={};function t(n){if(r[n])return r[n].exports;var o=r[n]={i:n,l:!1,exports:{}};return e[n].call(o.exports,o,o.exports,t),o.l=!0,o.exports}t.m=e,t.c=r,t.d=function(e,r,n){t.o(e,r)||Object.defineProperty(e,r,{configurable:!1,enumerable:!0,get:n})},t.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},t.n=function(e){var r=e&&e.__esModule?function(){return e.default}:function(){return e};return t.d(r,"a",r),r},t.o=function(e,r){return Object.prototype.hasOwnProperty.call(e,r)},t.p="",t(t.s=0)}([function(e,r,t){"use strict";t.r(r),r.default=(()=>"
more returned HTML
")}]); \ No newline at end of file diff --git a/test/fixtures/with-field/dist/index.html b/test/fixtures/with-field/dist/index.html new file mode 100644 index 0000000..be9eec4 --- /dev/null +++ b/test/fixtures/with-field/dist/index.html @@ -0,0 +1,8 @@ + +prerender field demo + + +
+
more returned HTML
+
+ \ No newline at end of file diff --git a/test/fixtures/with-field/index.html b/test/fixtures/with-field/index.html new file mode 100644 index 0000000..6ea056b --- /dev/null +++ b/test/fixtures/with-field/index.html @@ -0,0 +1,11 @@ + + + + prerender field demo + + +
+ {{prerender}} +
+ + diff --git a/test/fixtures/with-field/index.js b/test/fixtures/with-field/index.js new file mode 100644 index 0000000..60694e9 --- /dev/null +++ b/test/fixtures/with-field/index.js @@ -0,0 +1 @@ +export default () => `
more returned HTML
`; diff --git a/test/index.test.js b/test/index.test.js new file mode 100644 index 0000000..241297f --- /dev/null +++ b/test/index.test.js @@ -0,0 +1,135 @@ +/** + * Copyright 2018 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not + * use this file except in compliance with the License. You may obtain a copy of + * the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + */ + +import path from 'path'; +import HtmlWebpackPlugin from 'html-webpack-plugin'; +import { compile, compileToHtml, readFile } from './_helpers'; + +const PRERENDER_LOADER = path.resolve(__dirname, '../src'); + +const configure = prerenderLoaderOptions => config => { + let template = path.resolve(config.context, 'index.html'); + if (prerenderLoaderOptions === true) { + template = `!!${PRERENDER_LOADER}?string!${template}`; + } else if (prerenderLoaderOptions) { + template = `!!${PRERENDER_LOADER}?${JSON.stringify(prerenderLoaderOptions)}!${template}`; + } else { + template = `!!raw-loader!${template}`; + } + config.plugins.push( + new HtmlWebpackPlugin({ + filename: 'index.html', + template, + compile: false, + inject: true, + minify: { + collapseWhitespace: true, + preserveLineBreaks: true + } + }) + ); +}; + +const withoutPrerender = configure(false); +const withPrerender = configure(true); + +describe('webpack compilation smoke test (no prerendering)', () => { + it('should compile', async () => { + const info = await compile('fixtures/basic/index.js', withoutPrerender); + expect(info.assets).toHaveLength(2); + + const html = await readFile('fixtures/basic/dist/index.html'); + expect(html).toMatchSnapshot(); + }); + + it('should propagate child compiler errors', async () => { + await expect(compile('fixtures/failure/index.js', withPrerender)).rejects.toMatch(/does-not-exist/); + }); +}); + +describe('prerender-loader!x.html', () => { + describe('?disabled', async () => { + const { html } = await compileToHtml('basic', configure({ disabled: true, string: true })); + expect(html).not.toMatch(/
this counts as SSR<\/div>/); + }); + + describe('Imperative DOM, no {{prerender}} field', () => { + it('should return serialized HTML', async () => { + const { html, document } = await compileToHtml('basic', withPrerender); + + // verify that our DOM-generated content has been prerendered into the static HTML: + expect(html).toMatch(/
this counts as SSR<\/div>/); + // ... and that there's no extra children: + expect(document.body.children).toHaveLength(2); + // ... and that html-webpack-plugin was able to inject scripts after the content: + expect(document.body.firstElementChild).toHaveProperty('outerHTML', '
this counts as SSR
'); + expect(html).toMatchSnapshot(); + }); + }); + + describe('default export function, no {{prerender}} field', () => { + it('should inject returned HTML into ', async () => { + const { html, document } = await compileToHtml('factory', withPrerender); + + // verify that our DOM-generated content has been prerendered into the static HTML: + expect(html).toMatch(/
some returned HTML<\/div>/); + // ... and that there's no extra children: + expect(document.body.children).toHaveLength(2); + // ... and that html-webpack-plugin was able to inject scripts after the content: + expect(document.body.firstElementChild).toHaveProperty('outerHTML', '
some returned HTML
'); + expect(html).toMatchSnapshot(); + }); + }); + + describe('default export function, with {{prerender}} field', () => { + //
some returned HTML
+ it('should inject returned HTML in place of {{prerender}}', async () => { + const { html, document } = await compileToHtml('with-field', withPrerender); + + // verify that our DOM-generated content has been prerendered into the static HTML: + expect(html).toMatch(/
more returned HTML<\/div>/); + expect(document.body.children).toHaveLength(2); + // verify our the wrapper element that contained {{prerender}} is still present: + expect(document.body.firstElementChild).toHaveProperty('id', 'wrapper'); + // verify the wrapper element contains all of the prerendered content: + expect(document.getElementById('wrapper').innerHTML).toMatch(/^\s*
more returned HTML<\/div>\s*$/); + expect(html).toMatchSnapshot(); + }); + }); + + describe('named export function', () => { + it('should invoke the only named export', async () => { + const { html } = await compileToHtml('named-export-fn', withPrerender); + expect(html).toMatch(/
some HTML returned from prerender\(\)<\/div>/); + }); + }); + + describe('exported value', () => { + it('should invoke the only named export', async () => { + const { html } = await compileToHtml('value-export', withPrerender); + expect(html).toMatch(/
this is the resolved value of PRERENDERED_HTML<\/div>/); + }); + }); + + describe('exported function with no return value', () => { + it('should serialize the whole document', async () => { + const { html, document } = await compileToHtml('function-export-dom', withPrerender); + expect(html).toMatch(/
content injected into the dom<\/div>/); + expect(document.body.children).toHaveLength(2); + expect(html).toMatchSnapshot(); + }); + }); +});