Webpack style-loader / css-loader: url() 路径解析不起作用
Webpack style-loader / css-loader: url() path resolution not working
有一些关于 style-loader 和 css-loader 的 SO 帖子，但尽管如此，我仍无法找到解决问题的方法。
简而言之，当我在其他 css 文件中 @import css 文件时，导入的 css 包含 url() 具有相对路径，路径未正确解析。
基本上，错误消息显示 Webpack 最终认为导入的 css 中的 url() 路径是相对于 src（主入口点），而不是相对于导入到的 css 文件：
// css-one.scss
@import "./assets/open-iconic-master/font/css/open-iconic-bootstrap.css";
// open-iconic-bootstrap.css
@font-face {
src: url('../fonts/open-iconic.eot');
}
错误：
ERROR in ./src/main.scss
(./node_modules/css-loader??ref--5-1!./node_modules/postcss-loader/src??ref--5-2!./node_modules/sass-loader/lib/loader.js??ref--5-3!./src/main.scss)
Module not found: Error: Can't resolve '../fonts/open-iconic.eot' in
'C:\Users\...\src'
@ ./src/main.scss
(./node_modules/css-loader??ref--5-1!./node_modules/postcss-loader/src??ref--5-2!./node_modules/sass-loader/lib/loader.js??ref--5-3!./src/main.scss) 7:106-141 7:172-207 @ ./src/main.scss @ ./src/index.js
我尝试过的：
- 我尝试在 style-loader
中使用 convertToAbsoluteUrls 标志
- 我已经尝试关闭所有源映射(mentioned in style-loader docs)
我的 Webpack 配置文件（加载程序在底部）：
const path = require('path');
const webpack = require('webpack'); // for webpack built-in plugins
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
// const WriteFilePlugin = require('write-file-webpack-plugin');
// const ManifestPlugin = require('webpack-manifest-plugin');
// const InlineManifestWebpackPlugin = require('inline-manifest-webpack-plugin');
// const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
const PATHS = {
// when using __dirname, resolve and join gives same result,
// because __dirname is absolute path to directory of this file.
// OK to use no slashes,
// both resolve and join adds platform-specific separators by default
src: path.resolve(__dirname, 'src'),
dist: path.resolve(__dirname, 'dist'),
build: path.resolve(__dirname, 'build'),
test: path.resolve(__dirname, 'test')
};
const NAMES = {
// JS FILES
index: 'index',
print: 'print',
// Chrome Extension Development
popup: 'popup',
options: 'options',
background: 'background',
contentScript: 'contentScript',
// FOLDERS
assets: 'assets',
utilities: 'utilities',
images: 'images',
fonts: 'fonts',
include: 'include'
};
const FILE_PATHS = {
// JS
indexJs: `${path.join(PATHS.src, NAMES.index)}.js`,
printJs: `${path.join(PATHS.src, NAMES.print)}.js`,
// Chrome Extension Development
popupJs: `${path.join(PATHS.src, NAMES.popup)}.js`,
optionsJs: `${path.join(PATHS.src, NAMES.options)}.js`,
backgroundJs: `${path.join(PATHS.src, NAMES.background)}.js`,
contentScriptJs: `${path.join(
PATHS.src,
NAMES.include,
NAMES.contentScript
)}.js`,
// HTML
indexHtml: `${path.join(PATHS.src, NAMES.index)}.html`,
printHtml: `${path.join(PATHS.src, NAMES.print)}.html`,
// Chrome Extension Development
popupHtml: `${path.join(PATHS.src, NAMES.popup)}.html`,
optionsHtml: `${path.join(PATHS.src, NAMES.options)}.html`,
backgroundHtml: `${path.join(PATHS.src, NAMES.background)}.html`
};
// Third-party (vendor) libraries to include
// const VENDORS = ['react', 'bootstrap', 'lodash', 'jQuery']; // Relative paths to node_modules
// Note: These are relative
const ASSETS = {
images: path.join(NAMES.assets, NAMES.images),
fonts: path.join(NAMES.assets, NAMES.fonts)
};
// CleanWebpackPlugin config
const pathsToClean = [PATHS.dist, PATHS.build];
const cleanOptions = {
root: __dirname,
exclude: ['shared.js'],
verbose: true,
dry: false
};
// CopyWebpackPlugin config
const copyPattern = [
// {
// from: NAMES.assets,
// to: NAMES.assets
// },
// {
// from: path.join(NAMES.include, 'contentScript.css')
// },
// {
// from: 'manifest.json',
// transform(content, copyPath) {
// // generates the manifest file using the package.json informations
// return Buffer.from(
// JSON.stringify({
// ...JSON.parse(content.toString())
// // description: env.npm_package_description,
// // version: env.npm_package_version
// })
// );
// }
// }
];
const copyOptions = {
// ignore: ['*.js'],
context: PATHS.src
};
module.exports = (env = {}) => {
// webpack injects env variable, into webpack config.
// perfect to check for production.
// remember to specify --env.production in command
// (if in production mode).
const isProduction = env.production === true;
return {
entry: {
index: FILE_PATHS.indexJs
// Chrome Extension Development
// popup: FILE_PATHS.popupJs,
// contentScript: FILE_PATHS.contentScriptJs
// options: FILE_PATHS.optionsJs,
// background: FILE_PATHS.backgroundJs,
// vendor: VENDORS
},
mode: isProduction ? 'production' : 'development',
devtool: isProduction ? 'source-map' : 'inline-source-map',
optimization: {
splitChunks: {
chunks: 'all'
}
},
output: {
filename: isProduction ? '[name].[chunkhash:8].js' : '[name].js',
// chunkFilename determine name of non-entry chunk files,
// for example dynamic imports in the app
chunkFilename: isProduction ? '[name].[chunkhash:8].js' : '[name].js',
path: PATHS.dist
},
plugins: [
// new webpack.SourceMapDevToolPlugin({
// filename: '[file].map',
// exclude: ['vendor', 'runtime']
// }),
new webpack.DefinePlugin({
// specifies environment variable for dependencies.
// does not apply to browser runtime environment
// (process.env is provisioned by Node)
'process.env.NODE_ENV': isProduction ?
JSON.stringify('production') :
JSON.stringify('development')
}),
// new BundleAnalyzerPlugin(),
new CleanWebpackPlugin(pathsToClean, cleanOptions),
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
// does not work with Hot Module Replacement (HMR)
// allows HMR in development (will only use this plugin in production)
filename: isProduction ? '[name].[contenthash].css' : '[name].css',
chunkFilename: isProduction ? '[id].[contenthash].css' : '[id].css'
}),
new webpack.HashedModuleIdsPlugin(),
isProduction ?
new UglifyJSPlugin({
cache: true,
parallel: true,
sourceMap: true // set to true if you want JS source maps
}) :
() => {},
new CopyWebpackPlugin(copyPattern, copyOptions),
// new WriteFilePlugin(),
new HtmlWebpackPlugin({
template: FILE_PATHS.indexHtml,
filename: `${NAMES.index}.html`
})
// new HtmlWebpackPlugin({
// template: FILE_PATHS.popupHtml,
// filename: `${NAMES.popup}.html`,
// excludeChunks: [NAMES.contentScript]
// In dev mode, chunks excluded vendor chunk (which holds CSS).
// Above check fixes it.
// }),
// new HtmlWebpackPlugin({
// filename: `${NAMES.contentScript}.html`,
// excludeChunks: [NAMES.popup, 'runtime'] // Runtime only needed in one HTML
// }),
// new HtmlWebpackPlugin({
// template: FILE_PATHS.optionsHtml,
// filename: `${NAMES.options}.html`,
// chunks: isProduction ? [NAMES.options] : ''
// }),
// new HtmlWebpackPlugin({
// template: FILE_PATHS.backgroundHtml,
// filename: `${NAMES.background}.html`,
// chunks: isProduction ? [NAMES.background] : ''
// }),
// no need for CSS minimization here <-- Done by PostCSS (cssnano)
// new InlineManifestWebpackPlugin(),
// new ManifestPlugin({fileName: 'webpack-manifest.json'}),
],
module: {
rules: [{
test: /\.js$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader',
options: {
presets: ['@babel/preset-env']
}
}
},
{
test: /\.s?[ac]ss$/,
exclude: /node_modules/,
use: [
isProduction ?
MiniCssExtractPlugin.loader :
{
// creates style nodes from JS strings
loader: 'style-loader',
options: {
sourceMap: true,
convertToAbsoluteUrls: true
}
},
{
// CSS to CommonJS (resolves CSS imports into exported CSS strings)
loader: 'css-loader',
options: {
sourceMap: true,
importLoaders: 2
}
},
{
loader: 'postcss-loader',
options: {
config: {
ctx: {
cssnext: {},
cssnano: {},
autoprefixer: {}
}
},
sourceMap: true
}
},
{
// compiles Sass to CSS
loader: 'sass-loader',
options: {
sourceMap: true
}
}
]
},
{
test: /\.(png|svg|jpg|gif)$/,
use: [{
loader: 'file-loader',
options: {
name: '[name].[hash:4].[ext]',
outputPath: ASSETS.images
}
}]
},
{
test: /\.(woff|woff2|eot|ttf|otf)$/,
use: [{
loader: 'file-loader',
options: {
name: '[name].[hash:4].[ext]',
outputPath: ASSETS.fonts
}
}]
},
{
test: /\.(csv|tsv)$/,
use: ['csv-loader']
},
{
test: /\.xml$/,
use: ['xml-loader']
},
{
test: /\.(html)$/,
use: {
loader: 'html-loader',
options: {
interpolate: 'require',
minimize: true
}
}
}
// {
// test: /\.tsx?$/,
// exclude: /(node_modules|bower_components)/,
// use: 'ts-loader'
// }
]
},
devServer: {
// contentBase: path.join(__dirname, 'dist'),
contentBase: PATHS.dist,
compress: false,
port: 8080,
open: false
}
};
};
我自己解决了这个问题。如果以后对其他人有帮助，请在下面找到解决方案。
- 首先，如果您同时使用带有
postcss-import 插件的 postcss-loader 和 css-loader，请关闭/删除 postcss-import 插件。您不需要一种以上的工具来解决 @import 规则。如果加载程序的顺序正确，这不是真正的问题，但您最好将其删除。
- 在sass-loader docs, you can read the following中：
Since Sass/libsass does not provide url rewriting, all linked assets
must be relative to the output.
If you're just generating CSS without passing it to the css-loader, it must be relative to your web root.
If you pass the generated CSS on to the css-loader, all urls must be relative to the entry-file (e.g. main.scss).
More likely you will be disrupted by this second issue. It is natural to expect relative references to be resolved against the .scss file in which they are specified (like in regular .css files). Thankfully there are two solutions to this problem:
Add the missing url rewriting using the resolve-url-loader. Place it before the sass-loader in the loader chain.
Library authors usually provide a variable to modify the asset path. bootstrap-sass for example has an $icon-font-path. Check out this working bootstrap example.
我决定遵循第二点，并在 Webpack 配置中的 sass-loader 上方添加 resolve-url-loader。它现在按预期工作。
我的最终 Webpack 配置（目前）如下所示：
{
test: /\.s?[ac]ss$/,
exclude: /node_modules/,
use: [
isProduction
? MiniCssExtractPlugin.loader
: {
// creates style nodes from JS strings
loader: 'style-loader',
options: {
sourceMap: true,
// convertToAbsoluteUrls: true
}
},
{
// CSS to CommonJS (resolves CSS imports into exported CSS strings)
loader: 'css-loader',
options: {
sourceMap: true,
importLoaders: 2
// url: false,
// import: false
}
},
{
loader: 'postcss-loader',
options: {
config: {
ctx: {
cssnext: {},
cssnano: {},
autoprefixer: {}
}
},
sourceMap: true
}
},
{
loader: 'resolve-url-loader',
options: {
attempts: 1,
sourceMap: true
}
},
{
// compiles Sass to CSS
loader: 'sass-loader',
options: { sourceMap: true }
}
]
},
旁注
- 我注意到 Chrome 调试器中 "no domain" 下的源映射路径重复。如果有人知道原因，请分享
请记住在 package.json 中包含以下副作用，因此在生产模式下发生的 tree shaking 不会删除提取的 css
"sideEffects":[
".css",
“.scss”
],
我花了大约 5 天的时间才理解这个 webpack 混乱的工作原理。老实说，我可以说这是我真的不明白为什么它们是当下 "defacto" 工具的事情之一。我无法理解让配置文件正常工作有多困难，在 gulp 中我花了 1 小时才完成同样的工作。
我的问题是所有 url() 规则（包括字体和图像）都由 css-loader 作为 [object Module] 加载，并且它们由 file-loader 导出但从未加载过，所以如果我将 ?url=false 添加到 css-loader，它就不会复制文件并导出它们。我不得不说这完全是一个 PITA，但我让它工作了，我希望它对世界上的其他人有用，这是用 webpack 4 制作的。
const webpack = require("webpack");
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const ImageminPlugin = require('imagemin-webpack-plugin').default;
const CopyPlugin = require('copy-webpack-plugin');
module.exports = {
entry: "./src/index.js",
mode: "development",
module: {
rules: [
{
test: /\.(js|jsx)$/,
exclude: /(node_modules|bower_components)/,
loader: "babel-loader",
options: { presets: ["@babel/env"] }
},
{
test: /\.(gif|png|jpe?g|svg)$/i,
use: [
{
loader: 'image-webpack-loader',
options: {
mozjpeg: {
progressive: true,
quality: 65
},
optipng: {
enabled: false,
},
pngquant: {
quality: [0.65, 0.90],
speed: 4
},
gifsicle: {
interlaced: false,
},
webp: {
quality: 75
},
}
},
{
loader: 'file-loader',
options:{
name: '[name].[ext]',
outputPath: 'images/',
publicPath: 'images/'
}
},
'url-loader?limit=100000'
],
},
{
test: /\.(woff(2)?|ttf|eot)(\?v=\d+\.\d+\.\d+)?$/,
use: [
{
loader: 'file-loader',
options: {
name: '[name].[ext]',
outputPath: 'fonts/'
}
}
]
},
{
test: /\.s[ac]ss$/i,
use: [
MiniCssExtractPlugin.loader,
{ loader: 'css-loader?url=false'},
{ loader: 'sass-loader', options: { sourceMap: true } }
],
},
]
},
resolve: { extensions: ["*", ".js", ".jsx"] },
output: {
path: path.resolve(__dirname, "dist/"),
publicPath: "",
filename: "bundle.js"
},
devServer: {
contentBase: path.join(__dirname, "dist/"),
port: 3000,
publicPath: "http://localhost:3000/dist/",
hotOnly: true
},
plugins: [ new MiniCssExtractPlugin(),
new CopyPlugin([{ from: 'src/images/', to: 'images/' }]),
new CopyPlugin([{ from: 'src/fonts/', to: 'fonts/' }]),
new ImageminPlugin({ test: /\.(jpe?g|png|gif|svg)$/i }),
new HtmlWebpackPlugin({
hash: true,
template: './src/index.html',
filename: './index.html' //relative to root of the application
}),
]
};
顺便说一下，您可以关闭 url() 规则的处理。我不知道为什么这是默认行为。
{
loader: 'css-loader',
options: {
...
url: false,
}
},
如果有人正在使用 Webpack 5 解决这个问题并尝试从 css-loader 5 升级到 css-loader 6，您可能需要检查 this issue poster 与 OP 有类似的问题：
With css-loader 5.2.7 the images in the input stylus were embedded as data-
URL in the output CSS. With css-loader 6, the images are instead moved
to the output directory.
请参阅注释 here 了解如何升级到 css-loader 6 - 要点是：
using ~ is deprecated when the esModules option is enabled ... and can
be removed from your code
和
file-loader and url-loader are deprecated, please migrate on asset
modules, since v6 css-loader is generating new URL(...) syntax, it
enables by default built-in assets modules, i.e. type: 'asset' for all
url()
因此我做了以下事情：
- 删除了我的 .scss 文件中的所有“~”
即
$font-path: "~/src/fonts" !default;
变成
$font-path: "/src/fonts" !default;
- 我还完全删除了 'file-loader' 模块。
所有 NPM 包现在都是最新的并且 CSS 中的 URL 工作正常。
IE 不兼容新 URL()
有一些关于 style-loader 和 css-loader 的 SO 帖子，但尽管如此，我仍无法找到解决问题的方法。
简而言之，当我在其他 css 文件中 @import css 文件时，导入的 css 包含 url() 具有相对路径，路径未正确解析。
基本上，错误消息显示 Webpack 最终认为导入的 css 中的 url() 路径是相对于 src（主入口点），而不是相对于导入到的 css 文件：
// css-one.scss
@import "./assets/open-iconic-master/font/css/open-iconic-bootstrap.css";
// open-iconic-bootstrap.css
@font-face {
src: url('../fonts/open-iconic.eot');
}
错误：
ERROR in ./src/main.scss (./node_modules/css-loader??ref--5-1!./node_modules/postcss-loader/src??ref--5-2!./node_modules/sass-loader/lib/loader.js??ref--5-3!./src/main.scss)
Module not found: Error: Can't resolve '../fonts/open-iconic.eot' in 'C:\Users\...\src' @ ./src/main.scss (./node_modules/css-loader??ref--5-1!./node_modules/postcss-loader/src??ref--5-2!./node_modules/sass-loader/lib/loader.js??ref--5-3!./src/main.scss) 7:106-141 7:172-207 @ ./src/main.scss @ ./src/index.js
我尝试过的：
- 我尝试在 style-loader 中使用
- 我已经尝试关闭所有源映射(mentioned in style-loader docs)
convertToAbsoluteUrls 标志
我的 Webpack 配置文件（加载程序在底部）：
const path = require('path');
const webpack = require('webpack'); // for webpack built-in plugins
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
// const WriteFilePlugin = require('write-file-webpack-plugin');
// const ManifestPlugin = require('webpack-manifest-plugin');
// const InlineManifestWebpackPlugin = require('inline-manifest-webpack-plugin');
// const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
const PATHS = {
// when using __dirname, resolve and join gives same result,
// because __dirname is absolute path to directory of this file.
// OK to use no slashes,
// both resolve and join adds platform-specific separators by default
src: path.resolve(__dirname, 'src'),
dist: path.resolve(__dirname, 'dist'),
build: path.resolve(__dirname, 'build'),
test: path.resolve(__dirname, 'test')
};
const NAMES = {
// JS FILES
index: 'index',
print: 'print',
// Chrome Extension Development
popup: 'popup',
options: 'options',
background: 'background',
contentScript: 'contentScript',
// FOLDERS
assets: 'assets',
utilities: 'utilities',
images: 'images',
fonts: 'fonts',
include: 'include'
};
const FILE_PATHS = {
// JS
indexJs: `${path.join(PATHS.src, NAMES.index)}.js`,
printJs: `${path.join(PATHS.src, NAMES.print)}.js`,
// Chrome Extension Development
popupJs: `${path.join(PATHS.src, NAMES.popup)}.js`,
optionsJs: `${path.join(PATHS.src, NAMES.options)}.js`,
backgroundJs: `${path.join(PATHS.src, NAMES.background)}.js`,
contentScriptJs: `${path.join(
PATHS.src,
NAMES.include,
NAMES.contentScript
)}.js`,
// HTML
indexHtml: `${path.join(PATHS.src, NAMES.index)}.html`,
printHtml: `${path.join(PATHS.src, NAMES.print)}.html`,
// Chrome Extension Development
popupHtml: `${path.join(PATHS.src, NAMES.popup)}.html`,
optionsHtml: `${path.join(PATHS.src, NAMES.options)}.html`,
backgroundHtml: `${path.join(PATHS.src, NAMES.background)}.html`
};
// Third-party (vendor) libraries to include
// const VENDORS = ['react', 'bootstrap', 'lodash', 'jQuery']; // Relative paths to node_modules
// Note: These are relative
const ASSETS = {
images: path.join(NAMES.assets, NAMES.images),
fonts: path.join(NAMES.assets, NAMES.fonts)
};
// CleanWebpackPlugin config
const pathsToClean = [PATHS.dist, PATHS.build];
const cleanOptions = {
root: __dirname,
exclude: ['shared.js'],
verbose: true,
dry: false
};
// CopyWebpackPlugin config
const copyPattern = [
// {
// from: NAMES.assets,
// to: NAMES.assets
// },
// {
// from: path.join(NAMES.include, 'contentScript.css')
// },
// {
// from: 'manifest.json',
// transform(content, copyPath) {
// // generates the manifest file using the package.json informations
// return Buffer.from(
// JSON.stringify({
// ...JSON.parse(content.toString())
// // description: env.npm_package_description,
// // version: env.npm_package_version
// })
// );
// }
// }
];
const copyOptions = {
// ignore: ['*.js'],
context: PATHS.src
};
module.exports = (env = {}) => {
// webpack injects env variable, into webpack config.
// perfect to check for production.
// remember to specify --env.production in command
// (if in production mode).
const isProduction = env.production === true;
return {
entry: {
index: FILE_PATHS.indexJs
// Chrome Extension Development
// popup: FILE_PATHS.popupJs,
// contentScript: FILE_PATHS.contentScriptJs
// options: FILE_PATHS.optionsJs,
// background: FILE_PATHS.backgroundJs,
// vendor: VENDORS
},
mode: isProduction ? 'production' : 'development',
devtool: isProduction ? 'source-map' : 'inline-source-map',
optimization: {
splitChunks: {
chunks: 'all'
}
},
output: {
filename: isProduction ? '[name].[chunkhash:8].js' : '[name].js',
// chunkFilename determine name of non-entry chunk files,
// for example dynamic imports in the app
chunkFilename: isProduction ? '[name].[chunkhash:8].js' : '[name].js',
path: PATHS.dist
},
plugins: [
// new webpack.SourceMapDevToolPlugin({
// filename: '[file].map',
// exclude: ['vendor', 'runtime']
// }),
new webpack.DefinePlugin({
// specifies environment variable for dependencies.
// does not apply to browser runtime environment
// (process.env is provisioned by Node)
'process.env.NODE_ENV': isProduction ?
JSON.stringify('production') :
JSON.stringify('development')
}),
// new BundleAnalyzerPlugin(),
new CleanWebpackPlugin(pathsToClean, cleanOptions),
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
// does not work with Hot Module Replacement (HMR)
// allows HMR in development (will only use this plugin in production)
filename: isProduction ? '[name].[contenthash].css' : '[name].css',
chunkFilename: isProduction ? '[id].[contenthash].css' : '[id].css'
}),
new webpack.HashedModuleIdsPlugin(),
isProduction ?
new UglifyJSPlugin({
cache: true,
parallel: true,
sourceMap: true // set to true if you want JS source maps
}) :
() => {},
new CopyWebpackPlugin(copyPattern, copyOptions),
// new WriteFilePlugin(),
new HtmlWebpackPlugin({
template: FILE_PATHS.indexHtml,
filename: `${NAMES.index}.html`
})
// new HtmlWebpackPlugin({
// template: FILE_PATHS.popupHtml,
// filename: `${NAMES.popup}.html`,
// excludeChunks: [NAMES.contentScript]
// In dev mode, chunks excluded vendor chunk (which holds CSS).
// Above check fixes it.
// }),
// new HtmlWebpackPlugin({
// filename: `${NAMES.contentScript}.html`,
// excludeChunks: [NAMES.popup, 'runtime'] // Runtime only needed in one HTML
// }),
// new HtmlWebpackPlugin({
// template: FILE_PATHS.optionsHtml,
// filename: `${NAMES.options}.html`,
// chunks: isProduction ? [NAMES.options] : ''
// }),
// new HtmlWebpackPlugin({
// template: FILE_PATHS.backgroundHtml,
// filename: `${NAMES.background}.html`,
// chunks: isProduction ? [NAMES.background] : ''
// }),
// no need for CSS minimization here <-- Done by PostCSS (cssnano)
// new InlineManifestWebpackPlugin(),
// new ManifestPlugin({fileName: 'webpack-manifest.json'}),
],
module: {
rules: [{
test: /\.js$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader',
options: {
presets: ['@babel/preset-env']
}
}
},
{
test: /\.s?[ac]ss$/,
exclude: /node_modules/,
use: [
isProduction ?
MiniCssExtractPlugin.loader :
{
// creates style nodes from JS strings
loader: 'style-loader',
options: {
sourceMap: true,
convertToAbsoluteUrls: true
}
},
{
// CSS to CommonJS (resolves CSS imports into exported CSS strings)
loader: 'css-loader',
options: {
sourceMap: true,
importLoaders: 2
}
},
{
loader: 'postcss-loader',
options: {
config: {
ctx: {
cssnext: {},
cssnano: {},
autoprefixer: {}
}
},
sourceMap: true
}
},
{
// compiles Sass to CSS
loader: 'sass-loader',
options: {
sourceMap: true
}
}
]
},
{
test: /\.(png|svg|jpg|gif)$/,
use: [{
loader: 'file-loader',
options: {
name: '[name].[hash:4].[ext]',
outputPath: ASSETS.images
}
}]
},
{
test: /\.(woff|woff2|eot|ttf|otf)$/,
use: [{
loader: 'file-loader',
options: {
name: '[name].[hash:4].[ext]',
outputPath: ASSETS.fonts
}
}]
},
{
test: /\.(csv|tsv)$/,
use: ['csv-loader']
},
{
test: /\.xml$/,
use: ['xml-loader']
},
{
test: /\.(html)$/,
use: {
loader: 'html-loader',
options: {
interpolate: 'require',
minimize: true
}
}
}
// {
// test: /\.tsx?$/,
// exclude: /(node_modules|bower_components)/,
// use: 'ts-loader'
// }
]
},
devServer: {
// contentBase: path.join(__dirname, 'dist'),
contentBase: PATHS.dist,
compress: false,
port: 8080,
open: false
}
};
};
我自己解决了这个问题。如果以后对其他人有帮助，请在下面找到解决方案。
- 首先，如果您同时使用带有
postcss-import插件的postcss-loader和css-loader，请关闭/删除postcss-import插件。您不需要一种以上的工具来解决@import规则。如果加载程序的顺序正确，这不是真正的问题，但您最好将其删除。 - 在sass-loader docs, you can read the following中：
Since Sass/libsass does not provide url rewriting, all linked assets must be relative to the output.
If you're just generating CSS without passing it to the css-loader, it must be relative to your web root.
If you pass the generated CSS on to the css-loader, all urls must be relative to the entry-file (e.g. main.scss).
More likely you will be disrupted by this second issue. It is natural to expect relative references to be resolved against the .scss file in which they are specified (like in regular .css files). Thankfully there are two solutions to this problem:
Add the missing url rewriting using the resolve-url-loader. Place it before the sass-loader in the loader chain.
Library authors usually provide a variable to modify the asset path. bootstrap-sass for example has an $icon-font-path. Check out this working bootstrap example.
我决定遵循第二点，并在 Webpack 配置中的 sass-loader 上方添加 resolve-url-loader。它现在按预期工作。
我的最终 Webpack 配置（目前）如下所示：
{
test: /\.s?[ac]ss$/,
exclude: /node_modules/,
use: [
isProduction
? MiniCssExtractPlugin.loader
: {
// creates style nodes from JS strings
loader: 'style-loader',
options: {
sourceMap: true,
// convertToAbsoluteUrls: true
}
},
{
// CSS to CommonJS (resolves CSS imports into exported CSS strings)
loader: 'css-loader',
options: {
sourceMap: true,
importLoaders: 2
// url: false,
// import: false
}
},
{
loader: 'postcss-loader',
options: {
config: {
ctx: {
cssnext: {},
cssnano: {},
autoprefixer: {}
}
},
sourceMap: true
}
},
{
loader: 'resolve-url-loader',
options: {
attempts: 1,
sourceMap: true
}
},
{
// compiles Sass to CSS
loader: 'sass-loader',
options: { sourceMap: true }
}
]
},
旁注
- 我注意到 Chrome 调试器中 "no domain" 下的源映射路径重复。如果有人知道原因，请分享
请记住在
package.json中包含以下副作用，因此在生产模式下发生的 tree shaking 不会删除提取的 css"sideEffects":[ ".css", “.scss” ],
我花了大约 5 天的时间才理解这个 webpack 混乱的工作原理。老实说，我可以说这是我真的不明白为什么它们是当下 "defacto" 工具的事情之一。我无法理解让配置文件正常工作有多困难，在 gulp 中我花了 1 小时才完成同样的工作。
我的问题是所有 url() 规则（包括字体和图像）都由 css-loader 作为 [object Module] 加载，并且它们由 file-loader 导出但从未加载过，所以如果我将 ?url=false 添加到 css-loader，它就不会复制文件并导出它们。我不得不说这完全是一个 PITA，但我让它工作了，我希望它对世界上的其他人有用，这是用 webpack 4 制作的。
const webpack = require("webpack");
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const ImageminPlugin = require('imagemin-webpack-plugin').default;
const CopyPlugin = require('copy-webpack-plugin');
module.exports = {
entry: "./src/index.js",
mode: "development",
module: {
rules: [
{
test: /\.(js|jsx)$/,
exclude: /(node_modules|bower_components)/,
loader: "babel-loader",
options: { presets: ["@babel/env"] }
},
{
test: /\.(gif|png|jpe?g|svg)$/i,
use: [
{
loader: 'image-webpack-loader',
options: {
mozjpeg: {
progressive: true,
quality: 65
},
optipng: {
enabled: false,
},
pngquant: {
quality: [0.65, 0.90],
speed: 4
},
gifsicle: {
interlaced: false,
},
webp: {
quality: 75
},
}
},
{
loader: 'file-loader',
options:{
name: '[name].[ext]',
outputPath: 'images/',
publicPath: 'images/'
}
},
'url-loader?limit=100000'
],
},
{
test: /\.(woff(2)?|ttf|eot)(\?v=\d+\.\d+\.\d+)?$/,
use: [
{
loader: 'file-loader',
options: {
name: '[name].[ext]',
outputPath: 'fonts/'
}
}
]
},
{
test: /\.s[ac]ss$/i,
use: [
MiniCssExtractPlugin.loader,
{ loader: 'css-loader?url=false'},
{ loader: 'sass-loader', options: { sourceMap: true } }
],
},
]
},
resolve: { extensions: ["*", ".js", ".jsx"] },
output: {
path: path.resolve(__dirname, "dist/"),
publicPath: "",
filename: "bundle.js"
},
devServer: {
contentBase: path.join(__dirname, "dist/"),
port: 3000,
publicPath: "http://localhost:3000/dist/",
hotOnly: true
},
plugins: [ new MiniCssExtractPlugin(),
new CopyPlugin([{ from: 'src/images/', to: 'images/' }]),
new CopyPlugin([{ from: 'src/fonts/', to: 'fonts/' }]),
new ImageminPlugin({ test: /\.(jpe?g|png|gif|svg)$/i }),
new HtmlWebpackPlugin({
hash: true,
template: './src/index.html',
filename: './index.html' //relative to root of the application
}),
]
};
顺便说一下，您可以关闭 url() 规则的处理。我不知道为什么这是默认行为。
{
loader: 'css-loader',
options: {
...
url: false,
}
},
如果有人正在使用 Webpack 5 解决这个问题并尝试从 css-loader 5 升级到 css-loader 6，您可能需要检查 this issue poster 与 OP 有类似的问题：
With css-loader 5.2.7 the images in the input stylus were embedded as data- URL in the output CSS. With css-loader 6, the images are instead moved to the output directory.
请参阅注释 here 了解如何升级到 css-loader 6 - 要点是：
using ~ is deprecated when the esModules option is enabled ... and can be removed from your code
和
file-loader and url-loader are deprecated, please migrate on asset modules, since v6 css-loader is generating new URL(...) syntax, it enables by default built-in assets modules, i.e. type: 'asset' for all url()
因此我做了以下事情：
- 删除了我的 .scss 文件中的所有“~”
即
$font-path: "~/src/fonts" !default;
变成
$font-path: "/src/fonts" !default;
- 我还完全删除了 'file-loader' 模块。
所有 NPM 包现在都是最新的并且 CSS 中的 URL 工作正常。
IE 不兼容新 URL()