create-react-app VS webpack

We recommend going through the tutorial on building a tic-tac-toe game on the React homepage to get a feel of what React is and what it does. For more in-depth learning, check out the Egghead course, Build Your First Production Quality React App. It covers some advanced concepts and real-world usages that are not covered by the React documentation. Create React App by Facebook is a tool to scaffold a React project with minimal configuration and is highly recommended to use for starting new React projects.

Creating React App is a comfortable environment for learning React, and is the best way to start building a new single-page application in React.

I'm using facebook's create-react app for my application:

I'm developing a React app created with "create react app" (https://github.com/facebookincubator/create-react-app). It will be hosted in Firebase Hosting and I'll like to use implicit initialization as describe in documentation (https://firebase.google.com/docs/web/setup#sdk_imports_and_implicit_initialization), to deploy to multiple projects (I have a dev project and several production projects)

I am working on a website that I used create-react-app to create. I need to make a contact page where the information entered will be sent to a specified email.

'use strict';const autoprefixer = require('autoprefixer');const path = require('path');const webpack = require('webpack');const HtmlWebpackPlugin = require('html-webpack-plugin');const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');const eslintFormatter = require('react-dev-utils/eslintFormatter');const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');const getClientEnvironment = require('./env');const paths = require('./paths');const ExtractTextPlugin = require('extract-text-webpack-plugin');// Webpack uses `publicPath` to determine where the app is being served from.// In development, we always serve from the root. This makes config easier.const publicPath = '/';// `publicUrl` is just like `publicPath`, but we will provide it to our app// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.const publicUrl = '';// Get environment variables to inject into our app.const env = getClientEnvironment(publicUrl);// This is the development configuration.// It is focused on developer experience and fast rebuilds.// The production configuration is different and lives in a separate file.module.exports = { // You may want 'eval' instead if you prefer to see the compiled output in DevTools. // See the discussion in https://github.com/facebookincubator/create-react-app/issues/343. devtool: 'cheap-module-source-map', // These are the "entry points" to our application. // This means they will be the "root" imports that are included in JS bundle. // The first two entry points enable "hot" CSS and auto-refreshes for JS. entry: [ // Include an alternative client for WebpackDevServer. A client's job is to // connect to WebpackDevServer by a socket and get notified about changes. // When you save a file, the client will either apply hot updates (in case // of CSS changes), or refresh the page (in case of JS changes). When you // make a syntax error, this client will display a syntax error overlay. // Note: instead of the default WebpackDevServer client, we use a custom one // to bring better experience for Create React App users. You can replace // the line below with these two lines if you prefer the stock client: // require.resolve('webpack-dev-server/client') + '?/', // require.resolve('webpack/hot/dev-server'), require.resolve('react-dev-utils/webpackHotDevClient'), // We ship a few polyfills by default: require.resolve('./polyfills'), // Errors should be considered fatal in development require.resolve('react-error-overlay'), // Finally, this is your app's code: paths.appIndexJs, // We include the app code last so that if there is a runtime error during // initialization, it doesn't blow up the WebpackDevServer client, and // changing JS code would still trigger a refresh. ], output: { // Next line is not used in dev but WebpackDevServer crashes without it: path: paths.appBuild, // Add /* filename */ comments to generated require()s in the output. pathinfo: true, // This does not produce a real file. It's just the virtual path that is // served by WebpackDevServer in development. This is the JS bundle // containing code from all our entry points, and the Webpack runtime. filename: 'static/js/bundle.js', // There are also additional JS chunk files if you use code splitting. chunkFilename: 'static/js/[name].chunk.js', // This is the URL that app is served from. We use "/" in development. publicPath: publicPath, // Point sourcemap entries to original disk location (format as URL on Windows) devtoolModuleFilenameTemplate: info => path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'), }, resolve: { // This allows you to set a fallback for where Webpack should look for modules. // We placed these paths second because we want `node_modules` to "win" // if there are any conflicts. This matches Node resolution mechanism. // https://github.com/facebookincubator/create-react-app/issues/253 modules: ['node_modules', paths.appNodeModules].concat( // It is guaranteed to exist because we tweak it in `env.js` process.env.NODE_PATH.split(path.delimiter).filter(Boolean) ), // These are the reasonable defaults supported by the Node ecosystem. // We also include JSX as a common component filename extension to support // some tools, although we do not recommend using it, see: // https://github.com/facebookincubator/create-react-app/issues/290 // `web` extension prefixes have been added for better support // for React Native Web. extensions: ['.web.js', '.js', '.json', '.web.jsx', '.jsx'], alias: { // Support React Native Web // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/ 'react-native': 'react-native-web', }, plugins: [ // Prevents users from importing files from outside of src/ (or node_modules/). // This often causes confusion because we only process files within src/ with babel. // To fix this, we prevent you from importing files out of src/ -- if you'd like to, // please link the files into your node_modules/ and let module-resolution kick in. // Make sure your source files are compiled, as they will not be processed in any way. new ModuleScopePlugin(paths.appSrc), ], }, module: { strictExportPresence: true, rules: [ // TODO: Disable require.ensure as it's not a standard language feature. // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176. // { parser: { requireEnsure: false } }, // First, run the linter. // It's important to do this before Babel processes the JS. { test: /\.(js|jsx)$/, enforce: 'pre', use: [ { options: { formatter: eslintFormatter, }, loader: require.resolve('eslint-loader'), }, ], include: paths.appSrc, }, // ** ADDING/UPDATING LOADERS ** // The "file" loader handles all assets unless explicitly excluded. // The `exclude` list *must* be updated with every change to loader extensions. // When adding a new loader, you must add its `test` // as a new entry in the `exclude` list for "file" loader. // "file" loader makes sure those assets get served by WebpackDevServer. // When you `import` an asset, you get its (virtual) filename. // In production, they would get copied to the `build` folder. { exclude: [ /\.html$/, /\.(js|jsx)$/, /\.css$/, /\.json$/, /\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/, /\.scss$/ ], loader: require.resolve('file-loader'), options: { name: 'static/media/[name].[hash:8].[ext]', }, }, // "url" loader works like "file" loader except that it embeds assets // smaller than specified limit in bytes as data URLs to avoid requests. // A missing `test` is equivalent to a match. { test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/], loader: require.resolve('url-loader'), options: { limit: 10000, name: 'static/media/[name].[hash:8].[ext]', }, }, // Process JS with Babel. { test: /\.(js|jsx)$/, include: paths.appSrc, loader: require.resolve('babel-loader'), options: { // This is a feature of `babel-loader` for webpack (not Babel itself). // It enables caching results in ./node_modules/.cache/babel-loader/ // directory for faster rebuilds. cacheDirectory: true, }, }, // "postcss" loader applies autoprefixer to our CSS. // "css" loader resolves paths in CSS and adds assets as dependencies. // "style" loader turns CSS into JS modules that inject tags. // In production, we use a plugin to extract that CSS to a file, but // in development "style" loader enables hot editing of CSS. { test: /\.css$/, use: [ require.resolve('style-loader'), { loader: require.resolve('css-loader'), options: { importLoaders: 1, modules: true, localIdentName: "[name]__[local]___[hash:base64:5]" }, }, { loader: require.resolve('postcss-loader'), options: { // Necessary for external CSS imports to work // https://github.com/facebookincubator/create-react-app/issues/2677 ident: 'postcss', plugins: () => [ require('postcss-flexbugs-fixes'), autoprefixer({ browsers: [ '>1%', 'last 4 versions', 'Firefox ESR', 'not ie < 9', // React doesn't support IE8 anyway ], flexbox: 'no-2009', }), ], }, }, ], }, { test: /\.scss$/, use: ExtractTextPlugin.extract({ fallback:'style-loader', use: [ { loader: 'css-loader', q: { modules: true, sourcemap: true, importLoaders: 2, localIdentName: '[name]__[local]__[hash:base64:5]' } }, 'sass-loader' ] }), loaders: [ require.resolve('style-loader'), require.resolve('css-loader'), require.resolve('sass-loader') ] } // ** STOP ** Are you adding a new loader? // Remember to add the new extension(s) to the "file" loader exclusion list. ], }, plugins: [ // Makes some environment variables available in index.html. // The public URL is available as %PUBLIC_URL% in index.html, e.g.: // // In development, this will be an empty string. new InterpolateHtmlPlugin(env.raw), // Generates an `index.html` file with the injected. new HtmlWebpackPlugin({ inject: true, template: paths.appHtml, }), // Add module names to factory functions so they appear in browser profiler. new webpack.NamedModulesPlugin(), // Makes some environment variables available to the JS code, for example: // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`. new webpack.DefinePlugin(env.stringified), // This is necessary to emit hot updates (currently CSS only): new webpack.HotModuleReplacementPlugin(), // Watcher doesn't work well if you mistype casing in a path so we use // a plugin that prints an error when you attempt to do this. // See https://github.com/facebookincubator/create-react-app/issues/240 new CaseSensitivePathsPlugin(), // If you require a missing module and then `npm install` it, you still have // to restart the development server for Webpack to discover it. This plugin // makes the discovery automatic so you don't have to restart. // See https://github.com/facebookincubator/create-react-app/issues/186 new WatchMissingNodeModulesPlugin(paths.appNodeModules), // Moment.js is an extremely popular library that bundles large locale files // by default due to how Webpack interprets its code. This is a practical // solution that requires the user to opt into importing specific locales. // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack // You can remove this if you don't use Moment.js: new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/), new ExtractTextPlugin({'styles.css'}), ], // Some libraries import Node modules but don't use them in the browser. // Tell Webpack to provide empty mocks for them so importing them works. node: { dgram: 'empty', fs: 'empty', net: 'empty', tls: 'empty', }, // Turn off performance hints during development because we don't do any // splitting or minification in interest of speed. These warnings become // cumbersome. performance: { hints: false, },}; </code> Modal.js file :</p> <p><code> import React from "react";import ReactDOM from "react-dom";// import styles from "../css/popUpBox.css";import styles from "../css/modal.scss"; // ERROR HAPPENS HERE!! </code> ...file continues </p> <p>Package.json :</p> <p><code> { "name": "react-hackboard", "version": "0.1.0", "private": true, "dependencies": { "autoprefixer": "7.1.1", "babel-core": "6.25.0", "babel-eslint": "7.2.3", "babel-jest": "20.0.3", "babel-loader": "7.0.0", "babel-preset-react-app": "^3.0.1", "babel-runtime": "6.23.0", "case-sensitive-paths-webpack-plugin": "2.1.1", "chalk": "1.1.3", "css-loader": "0.28.4", "dotenv": "4.0.0", "eslint": "3.19.0", "eslint-config-react-app": "^1.0.5", "eslint-loader": "1.7.1", "eslint-plugin-flowtype": "2.34.0", "eslint-plugin-import": "2.2.0", "eslint-plugin-jsx-a11y": "5.0.3", "eslint-plugin-react": "7.1.0", "extract-text-webpack-plugin": "2.1.2", "file-loader": "0.11.2", "fs-extra": "3.0.1", "html-webpack-plugin": "2.29.0", "jest": "20.0.4", "node-sass": "^4.5.3", "object-assign": "4.1.1", "postcss-flexbugs-fixes": "3.0.0", "postcss-loader": "2.0.6", "promise": "7.1.1", "react": "^15.6.1", "react-dev-utils": "^3.0.2", "react-dom": "^15.6.1", "react-error-overlay": "^1.0.9", "react-redux": "^5.0.5", "redux": "^3.7.2", "redux-createreducer": "^2.0.0", "redux-thunk": "^2.2.0", "sass-loader": "^6.0.6", "style-loader": "0.18.2", "sw-precache-webpack-plugin": "0.11.3", "url-loader": "0.5.9", "webpack": "2.6.1", "webpack-dev-server": "2.5.0", "webpack-manifest-plugin": "1.1.0", "whatwg-fetch": "2.0.3" }, "scripts": { "start": "node scripts/start.js", "build": "node scripts/build.js", "test": "node scripts/test.js --env=jsdom" }, "jest": { "collectCoverageFrom": [ "src/**/*.{js,jsx}" ], "setupFiles": [ "<rootDir>/config/polyfills.js" ], "testMatch": [ "<rootDir>/src/**/__tests__/**/*.js?(x)", "<rootDir>/src/**/?(*.)(spec|test).js?(x)" ], "testEnvironment": "node", "testURL": "http://localhost", "transform": { "^.+\\.(js|jsx)$": "<rootDir>/node_modules/babel-jest", "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js", "^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js" }, "transformIgnorePatterns": [ "[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$" ], "moduleNameMapper": { "^react-native$": "react-native-web" }, "moduleFileExtensions": [ "web.js", "js", "json", "web.jsx", "jsx" ] }, "babel": { "presets": [ "react-app" ] }, "eslintConfig": { "extends": "react-app" }, "devDependencies": { "node-sass": "^4.5.3", "sass-loader": "^6.0.6", "webpack": "^2.6.1" }} </code></p> <p>Answer link : <a href="https://codehunter.cc/a/reactjs/module-not-found-cant-resolve-style">https://codehunter.cc/a/reactjs/module-not-found-cant-resolve-style</a></p> </div><!-- SC_ON -->

Is there a way to specify caching headers somewhere in my react project? I also read over the create-react-app user guide, and they say you can use a .htaccess file for Apache HTTP server. Is there something similar to that I should be leveraging?

I started an app using create-react-app, and I have this Error Boundary component:

UPDATE: The app was created using create-react-app 1.0.17 and later ejected.

I've created a React application with create-react-app

There are various tools available that manage the size of bundled assets. We are going to use the example of a popular and widely used bundler named Webpack, and practically look at many of the optimization techniques it offers.

Homepage: https://webpack.js.org/

Click "Start Test." WebPageTest generates a comprehensive report with details about the loading process, including time to first byte (TTFB), page load time, and visual progress. ### Setting Benchmarks with Lighthouse Start with Lighthouse audits to maximize the performance of your React application. Evaluate Lighthouse's scores and suggestions with careful consideration. Next, set benchmarks that are in line with industry norms or customized to meet your unique performance goals. Lastly, pay close attention to the places in your application where it needs work. You can improve your React application's effectiveness by carefully following these procedures, which will guarantee that it satisfies the required performance requirements. ### Analyzing Performance Results with WebPageTest In order to fully evaluate your webpage's performance, launch WebPageTest with a variety of systems, simulating a variety of user scenarios. Examine the waterfall chart carefully to identify loading patterns and bottlenecks, which are essential for improving the user experience. To see the page's rendering process over time and do a thorough examination, use filmstrip views. To effectively assess performance, pay special attention to measures such as time to first byte (TTFB), start render time, and fully loaded time. Also, a better understanding of performance variances is made possible by comparing findings across various test designs, which helps make well-informed recommendations for improving webpage responsiveness and efficiency. ## Impact of third-party libraries on React app performance Third-party library integration can speed up development while improving functionality in our React application. It's crucial to consider the possible effects on performance, though. Because heavy or poorly optimized libraries might negatively impact the speed and usability of our application. ### Bundle Size Look at the distribution file sizes related to the library, and use tools such as Bundlephobia or Webpack Bundle Analyzer to fully evaluate their impact on your bundle size. This thorough analysis enables you to make well-informed decisions about whether to include the library, making sure that its contribution minimizes superfluous bulk in your application's codebase and is in line with your optimization goals. ### Network Requests Analyze how the third-party library affects network requests to maximize performance. Reduce the number of requests made overall by minimizing external dependencies. This will enhance the user experience and loading speeds. Select appropriate libraries, maximize asset delivery, and leverage code splitting to load components asynchronously. You may improve the effectiveness and responsiveness of your application and provide users with a better experience by cutting down on pointless network queries. ### Execution Time Examine the library's code for any possible performance problems or bottlenecks in order to analyze the runtime performance of the library. Look for places where the code may execute slowly or inefficiently. You may ensure smoother operation inside your application by identifying and addressing any areas of the library's implementation that may be impeding ideal performance by doing a comprehensive assessment. ### Code Splitting for Third-Party Libraries Implementing code splitting is an effective strategy to load third-party libraries only when they are required, reducing the initial page load time. Use dynamic imports to load the library lazily:

Thanks for the thorough answer!

I confess I wasn't thinking about a particular build tool. My recent experience has been with Vite, where I took a similar approach to what you describe, but haven't had to dig deep into bundle performance because that's not a bottleneck for our application. The last time I did deeper work on the subject was years ago with Webpack.

I thought Webpack at least did dead-code elimination before splitting things into chunks. If I'm reading this random GitHub issue[1] right (and the asker is also right), Webpack does partially behave as I expected, but the pre-chunking optimization pass occurs before things like constant expression evaluation.

[1] https://github.com/webpack/webpack/issues/16672

Webpack is a powerful and widely-used module bundler for JavaScript applications. It’s known for its flexibility and extensive plugin system, making it a popular tool in complex web development projects.

Thats all about Webpack Basic, there are lots of feature of webpack, You can check here: https://webpack.js.org/

Many web pages use CSS and JavaScript files to handle various features and styles. Each file, however, requires a separate HTTP request, which can slow down page loading. Concatenation comes into play here. It involves combining multiple CSS or JavaScript files into a single file. As a result, pages load faster, reducing the time spent requesting individual files. Gulp, Grunt, and Webpack are some of the tools that can assist you in speeding up the concatenation process. They enable seamless merging of many files during development, ensuring deployment readiness.

Once you build a simple Vite backend integration, try not to complicate Vite's configuration unless you absolutely must. Vite has become one of the most popular bundlers in the frontend space, but it wasn't the first and it certainly won't be the last. In my 7 years of building for the web, I've used Grunt, Gulp, Webpack, esbuild, and Parcel. Snowpack and Rome came-and-went before I ever had a chance to try them. Bun is vying for the spot of The New Hotness in bundling, Rome has been forked into Biome, and Vercel is building a Rust-based Webpack alternative.

Webpack is a module bundler, the main purpose of which is to bundle JavaScript files to make them usable in a browser.