最新版的create-react-app如何添加less
- 运行
npm run eject将webpack的配置暴露出来如下：
PS C:\Users\29525\Desktop\me\my-app> npm run eject
> [email protected] eject C:\Users\29525\Desktop\me\my-app
> react-scripts eject
NOTE: Create React App 2 supports TypeScript, Sass, CSS Modules and more without ejecting: https://reactjs.org/blog/2018/10/01/create-react-app-v2.html
? Are you sure you want to eject? This action is permanent. Yes
Ejecting...
Copying files into C:\Users\29525\Desktop\me\my-app
Adding \config\env.js to the project
Adding \config\paths.js to the project
Adding \config\webpack.config.js to the project
Adding \config\webpackDevServer.config.js to the project
Adding \config\jest\cssTransform.js to the project
Adding \config\jest\fileTransform.js to the project
Adding \scripts\build.js to the project
Adding \scripts\start.js to the project
Adding \scripts\test.js to the project
Updating the dependencies
Removing react-scripts from dependencies
Adding @babel/core to dependencies
Adding @svgr/webpack to dependencies
Adding babel-core to dependencies
Adding babel-eslint to dependencies
Adding babel-jest to dependencies
Adding babel-loader to dependencies
Adding babel-plugin-named-asset-import to dependencies
Adding babel-preset-react-app to dependencies
Adding bfj to dependencies
Adding case-sensitive-paths-webpack-plugin to dependencies
Adding css-loader to dependencies
Adding dotenv to dependencies
Adding dotenv-expand to dependencies
Adding eslint to dependencies
Adding eslint-config-react-app to dependencies
Adding eslint-loader to dependencies
Adding eslint-plugin-flowtype to dependencies
Adding eslint-plugin-import to dependencies
Adding eslint-plugin-jsx-a11y to dependencies
Adding eslint-plugin-react to dependencies
Adding file-loader to dependencies
Adding fs-extra to dependencies
Adding html-webpack-plugin to dependencies
Adding identity-obj-proxy to dependencies
Adding jest to dependencies
Adding jest-pnp-resolver to dependencies
Adding jest-resolve to dependencies
Adding jest-watch-typeahead to dependencies
Adding mini-css-extract-plugin to dependencies
Adding optimize-css-assets-webpack-plugin to dependencies
Adding pnp-webpack-plugin to dependencies
Adding postcss-flexbugs-fixes to dependencies
Adding postcss-loader to dependencies
Adding postcss-preset-env to dependencies
Adding postcss-safe-parser to dependencies
Adding react-app-polyfill to dependencies
Adding react-dev-utils to dependencies
Adding resolve to dependencies
Adding sass-loader to dependencies
Adding style-loader to dependencies
Adding terser-webpack-plugin to dependencies
Adding url-loader to dependencies
Adding webpack to dependencies
Adding webpack-dev-server to dependencies
Adding webpack-manifest-plugin to dependencies
Adding workbox-webpack-plugin to dependencies
Updating the scripts
Replacing "react-scripts start" with "node scripts/start.js"
Replacing "react-scripts build" with "node scripts/build.js"
Replacing "react-scripts test" with "node scripts/test.js"
Configuring package.json
Adding Jest configuration
Adding Babel preset
Adding ESLint configuration
- 修改
webpack.config.js的webpack配置文件：由于脚手架默认集成了sass的配置。所以直接模改less就ok了。如下图
- *使用如下图
- 附上完整的
webpack.config.js
'use strict';
const fs = require('fs');
const path = require('path');
const webpack = require('webpack');
const resolve = require('resolve');
const PnpWebpackPlugin = require('pnp-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
const InlineChunkHtmlPlugin = require('react-dev-utils/InlineChunkHtmlPlugin');
const TerserPlugin = require('terser-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const safePostCssParser = require('postcss-safe-parser');
const ManifestPlugin = require('webpack-manifest-plugin');
const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
const WorkboxWebpackPlugin = require('workbox-webpack-plugin');
const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
const paths = require('./paths');
const getClientEnvironment = require('./env');
const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
const ForkTsCheckerWebpackPlugin = require('react-dev-utils/ForkTsCheckerWebpackPlugin');
const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
// Source maps are resource heavy and can cause out of memory issue for large source files.
const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
// Some apps do not need the benefits of saving a web request, so not inlining the chunk
// makes for a smoother build process.
const shouldInlineRuntimeChunk = process.env.INLINE_RUNTIME_CHUNK !== 'false';
// Check if TypeScript is setup
const useTypeScript = fs.existsSync(paths.appTsConfig);
// style files regexes
const cssRegex = /\.css$/;
const cssModuleRegex = /\.module\.css$/;
const sassRegex = /\.(scss|sass)$/;
const sassModuleRegex = /\.module\.(scss|sass)$/;
const lessRegex = /\.less$/;
const lessModuleRegex = /\.module\.less$/;
// This is the production and development configuration.
// It is focused on developer experience, fast rebuilds, and a minimal bundle.
module.exports = function(webpackEnv) {
const isEnvDevelopment = webpackEnv === 'development';
const isEnvProduction = webpackEnv === 'production';
// Webpack uses `publicPath` to determine where the app is being served from.
// It requires a trailing slash, or the file assets will get an incorrect path.
// In development, we always serve from the root. This makes config easier.
const publicPath = isEnvProduction
? paths.servedPath
: isEnvDevelopment && '/';
// Some apps do not use client-side routing with pushState.
// For these, "homepage" can be set to "." to enable relative asset paths.
const shouldUseRelativeAssetPaths = 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_URL%/xyz looks better than %PUBLIC_URL%xyz.
const publicUrl = isEnvProduction
? publicPath.slice(0, -1)
: isEnvDevelopment && '';
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl);
// common function to get style loaders
const getStyleLoaders = (cssOptions, preProcessor) => {
const loaders = [
isEnvDevelopment && require.resolve('style-loader'),
isEnvProduction && {
loader: MiniCssExtractPlugin.loader,
options: Object.assign(
{},
shouldUseRelativeAssetPaths ? { publicPath: '../../' } : undefined
),
},
{
loader: require.resolve('css-loader'),
options: cssOptions,
},
{
// Options for PostCSS as we reference these options twice
// Adds vendor prefixing based on your specified browser support in
// package.json
loader: require.resolve('postcss-loader'),
options: {
// Necessary for external CSS imports to work
// https://github.com/facebook/create-react-app/issues/2677
ident: 'postcss',
plugins: () => [
require('postcss-flexbugs-fixes'),
require('postcss-preset-env')({
autoprefixer: {
flexbox: 'no-2009',
},
stage: 3,
}),
],
sourceMap: isEnvProduction && shouldUseSourceMap,
},
},
].filter(Boolean);
if (preProcessor) {
loaders.push({
loader: require.resolve(preProcessor),
options: {
sourceMap: isEnvProduction && shouldUseSourceMap,
},
});
}
return loaders;
};
return {
mode: isEnvProduction ? 'production' : isEnvDevelopment && 'development',
// Stop compilation early in production
bail: isEnvProduction,
devtool: isEnvProduction
? shouldUseSourceMap
? 'source-map'
: false
: isEnvDevelopment && '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.
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'),
isEnvDevelopment &&
require.resolve('react-dev-utils/webpackHotDevClient'),
// 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.
].filter(Boolean),
output: {
// The build folder.
path: isEnvProduction ? paths.appBuild : undefined,
// Add /* filename */ comments to generated require()s in the output.
pathinfo: isEnvDevelopment,
// There will be one main bundle, and one file per asynchronous chunk.
// In development, it does not produce real files.
filename: isEnvProduction
? 'static/js/[name].[contenthash:8].js'
: isEnvDevelopment && 'static/js/bundle.js',
// There are also additional JS chunk files if you use code splitting.
chunkFilename: isEnvProduction
? 'static/js/[name].[contenthash:8].chunk.js'
: isEnvDevelopment && 'static/js/[name].chunk.js',
// We inferred the "public path" (such as / or /my-project) from homepage.
// We use "/" in development.
publicPath: publicPath,
// Point sourcemap entries to original disk location (format as URL on Windows)
devtoolModuleFilenameTemplate: isEnvProduction
? info =>
path
.relative(paths.appSrc, info.absoluteResourcePath)
.replace(/\\/g, '/')
: isEnvDevelopment &&
(info => path.resolve(info.absoluteResourcePath).replace(/\\/g, '/')),
},
optimization: {
minimize: isEnvProduction,
minimizer: [
// This is only used in production mode
new TerserPlugin({
terserOptions: {
parse: {
// we want terser to parse ecma 8 code. However, we don't want it
// to apply any minfication steps that turns valid ecma 5 code
// into invalid ecma 5 code. This is why the 'compress' and 'output'
// sections only apply transformations that are ecma 5 safe
// https://github.com/facebook/create-react-app/pull/4234
ecma: 8,
},
compress: {
ecma: 5,
warnings: false,
// Disabled because of an issue with Uglify breaking seemingly valid code:
// https://github.com/facebook/create-react-app/issues/2376
// Pending further investigation:
// https://github.com/mishoo/UglifyJS2/issues/2011
comparisons: false,
// Disabled because of an issue with Terser breaking valid code:
// https://github.com/facebook/create-react-app/issues/5250
// Pending futher investigation:
// https://github.com/terser-js/terser/issues/120
inline: 2,
},
mangle: {
safari10: true,
},
output: {
ecma: 5,
comments: false,
// Turned on because emoji and regex is not minified properly using default
// https://github.com/facebook/create-react-app/issues/2488
ascii_only: true,
},
},
// Use multi-process parallel running to improve the build speed
// Default number of concurrent runs: os.cpus().length - 1
parallel: true,
// Enable file caching
cache: true,
sourceMap: shouldUseSourceMap,
}),
// This is only used in production mode
new OptimizeCSSAssetsPlugin({
cssProcessorOptions: {
parser: safePostCssParser,
map: shouldUseSourceMap
? {
// `inline: false` forces the sourcemap to be output into a
// separate file
inline: false,
// `annotation: true` appends the sourceMappingURL to the end of
// the css file, helping the browser find the sourcemap
annotation: true,
}
: false,
},
}),
],
// Automatically split vendor and commons
// https://twitter.com/wSokra/status/969633336732905474
// https://medium.com/webpack/webpack-4-code-splitting-chunk-graph-and-the-splitchunks-optimization-be739a861366
splitChunks: {
chunks: 'all',
name: false,
},
// Keep the runtime chunk separated to enable long term caching
// https://twitter.com/wSokra/status/969679223278505985
runtimeChunk: true,
},
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/facebook/create-react-app/issues/253
modules: ['node_modules'].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/facebook/create-react-app/issues/290
// `web` extension prefixes have been added for better support
// for React Native Web.
extensions: paths.moduleFileExtensions
.map(ext => `.${ext}`)
.filter(ext => useTypeScript || !ext.includes('ts')),
alias: {
// Support React Native Web
// https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
'react-native': 'react-native-web',
},
plugins: [
// Adds support for installing with Plug'n'Play, leading to faster installs and adding
// guards against forgotten dependencies and such.
PnpWebpackPlugin,
// Prevents users from importing files from outside of src/ (or node_modules/).
// This often causes confusion because we only process files within src/ with babel.
// To fix this, we prevent you from importing files out of src/ -- if you'd like to,
// please link the files into your node_modules/ and let module-resolution kick in.
// Make sure your source files are compiled, as they will not be processed in any way.
new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
],
},
resolveLoader: {
plugins: [
// Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
// from the current package.
PnpWebpackPlugin.moduleLoader(module),
],
},
module: {
strictExportPresence: true,
rules: [
// Disable require.ensure as it's not a standard language feature.
{ parser: { requireEnsure: false } },
// First, run the linter.
// It's important to do this before Babel processes the JS.
{
test: /\.(js|mjs|jsx)$/,
enforce: 'pre',
use: [
{
options: {
formatter: require.resolve('react-dev-utils/eslintFormatter'),
eslintPath: require.resolve('eslint'),
},
loader: require.resolve('eslint-loader'),
},
],
include: paths.appSrc,
},
{
// "oneOf" will traverse all following loaders until one will
// match the requirements. When no loader matches it will fall
// back to the "file" loader at the end of the loader list.
oneOf: [
// "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 application JS with Babel.
// The preset includes JSX, Flow, TypeScript, and some ESnext features.
{
test: /\.(js|mjs|jsx|ts|tsx)$/,
include: paths.appSrc,
loader: require.resolve('babel-loader'),
options: {
customize: require.resolve(
'babel-preset-react-app/webpack-overrides'
),
plugins: [
[
require.resolve('babel-plugin-named-asset-import'),
{
loaderMap: {
svg: {
ReactComponent: '@svgr/webpack?-svgo,+ref![path]',
},
},
},
],
],
// This is a feature of `babel-loader` for webpack (not Babel itself).
// It enables caching results in ./node_modules/.cache/babel-loader/
// directory for faster rebuilds.
cacheDirectory: true,
cacheCompression: isEnvProduction,
compact: isEnvProduction,
},
},
// Process any JS outside of the app with Babel.
// Unlike the application JS, we only compile the standard ES features.
{
test: /\.(js|mjs)$/,
exclude: /@babel(?:\/|\\{1,2})runtime/,
loader: require.resolve('babel-loader'),
options: {
babelrc: false,
configFile: false,
compact: false,
presets: [
[
require.resolve('babel-preset-react-app/dependencies'),
{ helpers: true },
],
],
cacheDirectory: true,
cacheCompression: isEnvProduction,
// If an error happens in a package, it's possible to be
// because it was compiled. Thus, we don't want the browser
// debugger to show the original code. Instead, the code
// being evaluated would be much more helpful.
sourceMaps: false,
},
},
// "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