Develop Reference

Webpack url() path resolution with css-loader

I am developing a site and using webpack for obvious reasons. The problem I am having is with path resolution for images which are imported into my project via my SCSS files. The issue is that css-loader isn't resolving the correct path. What seems to be happening is the following:
If I allow css-loader to handle the url() imports (leaving the url option to true) it rewrites the file path relative to the output directory specified in ExtractCSSChunksPlugin(), for example:
url('../img/an-image.jpg') should be rewritten to url('http://localhost:3000/assets/img/an-image.jpg'), however, what is actually being outputted is url('http://localhost:3000/assets/css/assets/img/an-image.jpg').
If I change it to false the correct path is resolved but the file-loader isn't able to find the images and then emit them.
I know that the images are being outputted when the css-loader is handling url resolution as I can see the emitted message when the bundle is compiled -- it does not fail.
I can also get the images to display if I manually add import calls to them in the JS entry point, set in the entry: field, and then call the absolute path in SCSS. But this is not desirable as it becomes tedious with the growing project.
I have tried to use resolve-url-loader and changing multiple settings but I just can't seem to get this to work.
I have also tried using the resolve: { alias: { Images: path.resolve(__dirname, 'src/assets/img/' } } option provided by webpack and then calling url('~Images/an-image.jpg') in my SCSS but it just reproduces the same results.
So, overall, my issue is that I need to be able to use relative paths in my SCSS and then have them rewritten to the correct path by one of my loaders.
My current webpack config (outputting the files with file loader but prepending assets/css/ to the start of the url) is as follows:
"use strict";
const webpack = require('webpack');
const merge = require('webpack-merge');
const common = require('./webpack.common');
const ExtractCSSChunksPlugin = require('extract-css-chunks-webpack-plugin');
module.exports = merge(common, {
mode: 'development',
devtool: 'inline-source-map',
entry: [
'webpack-hot-middleware/client',
],
module: {
rules: [
{
test: /\.js$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader',
options: {
presets: ['#babel/preset-env'],
}
}
},
{
test: /\.scss$/,
use: [
{
loader: ExtractCSSChunksPlugin.loader,
options: {
hot: true,
}
},
{
loader: 'css-loader',
options: {
sourceMap: true,
}
},
{
loader: 'sass-loader',
options: {
sourceMap: true,
}
}
]
},
{
test: /\.html$/,
use:['html-loader']
},
{
test:/\.(svg|jpg|png|gif)$/,
use: [{
loader:'file-loader',
options: {
publicPath: 'assets/img',
outputPath: 'assets/img',
name: '[name].[ext]',
esModule: false
}
}],
},
]
},
plugins: [
new webpack.HotModuleReplacementPlugin(),
new ExtractCSSChunksPlugin({
filename: 'assets/css/[name].css',
chunkFilename: 'assets/css/[id].css',
}),
]
});
Thank you in advance.

Ok, so it seems I have fixed the issue by resolving the publicPath set in the file loader config field: publicPath: path.resolve(__dirname, '/assets/img').
My config is now:
"use strict";
const webpack = require('webpack');
const merge = require('webpack-merge');
const common = require('./webpack.common');
const path = require('path');
const ExtractCSSChunksPlugin = require('extract-css-chunks-webpack-plugin');
module.exports = merge(common, {
mode: 'development',
devtool: 'inline-source-map',
entry: [
'webpack-hot-middleware/client',
],
module: {
rules: [
{
test: /\.js$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader',
options: {
presets: ['#babel/preset-env'],
}
}
},
{
test: /\.scss$/,
use: [
{
loader: ExtractCSSChunksPlugin.loader,
options: {
hot: true,
}
},
{
loader: 'css-loader',
options: {
sourceMap: true,
}
},
{
loader: 'sass-loader',
options: {
sourceMap: true,
}
}
]
},
{
test: /\.html$/,
use:['html-loader']
},
{
test:/\.(svg|jpg|png|gif)$/,
use: [{
loader:'file-loader',
options: {
publicPath: path.resolve(__dirname, '/assets/img'),
outputPath: 'assets/img',
name: '[name].[ext]',
esModule: false
}
}],
},
]
},
plugins: [
new webpack.HotModuleReplacementPlugin(),
new ExtractCSSChunksPlugin({
filename: 'assets/css/[name].css',
chunkFilename: 'assets/css/[id].css',
}),
]
});

I think adding url loader in the webpack configuration would help.
{
test: /\.(jpg|png)$/,
use: {
loader: "url-loader",
options: {
limit: 25000,
},
},
},

webpack 4 gives background: url([object Module]) as bg image

I'm having issues with setting up web-pack 4 and svg-sprite-loader to render svg icons as background images. I was following these instructions from official docs for svg-sprite-loader (https://github.com/kisenka/svg-sprite-loader/tree/master/examples/extract-mode).
I have successfully managed to create sprite.svg file in my dist folder and use it as reference for my use tags inside of html. However, i was also trying to use svg icons from my src/images/icons folder for a background image like this:
background: url('../images/icons/upload_icon.svg') 10% 50% no-repeat;
when doing this, webpack compiles correctly, but creates this in dist css file:
background: url([object Module]) 10% 50% no-repeat;
Any help would be great.
here is my webpack config file:
const path = require("path");
const webpack = require("webpack");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CleanWebpackPlugin = require("clean-webpack-plugin");
const SpriteLoaderPlugin = require("svg-sprite-loader/plugin");
module.exports = {
mode: "development",
devtool: "source-map",
output: {
filename: "bundle.js",
path: path.resolve(__dirname, "dist")
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: "babel-loader",
options: {
sourceMap: true
}
}
},
{
// scss configuration
test: /\.scss$/,
use: [
MiniCssExtractPlugin.loader,
{
loader: "css-loader"
},
{
loader: "postcss-loader"
},
{
loader: "sass-loader",
options: {
sourceMap: true
}
}
]
},
{
// html configuration
test: /\.html$/,
use: {
loader: "html-loader"
}
},
{
// images configuration
test: /\.(jpg|jpeg|gif|png|woff|woff2)$/,
use: [
{
loader: "file-loader",
options: {
name: "[path][name].[ext]"
}
}
]
},
{
test: /\.svg$/,
use: [
{
loader: "svg-sprite-loader",
options: {
extract: true,
spriteFilename: "sprite.svg"
}
}
]
}
]
},
plugins: [
// all plugins used for compiling by webpack
new CleanWebpackPlugin(),
new HtmlWebpackPlugin({
title: "Style Guide",
template: path.resolve(__dirname, "src", "index.html")
}),
new MiniCssExtractPlugin({
filename: "app.css"
}),
new SpriteLoaderPlugin()
]
};

Adding esModule: false to the file-loader options did the trick for me.
{
test: /\.(jpg|png|gif|svg)$/,
use: {
loader: 'file-loader',
options: {
name: "[name].[ext]",
outputPath: "img",
esModule: false
}
},

You have to pass esModule: false for svg-sprite-loader options.
By the way (it is not related to esModule): With MiniCssExtractPlugin you can not to extract svg sprite. I've faced this problem one hour ago..

After a few hours, I have managed to make this thing to work, thanks to #WimmDeveloper for pointing me in right direction. Main change from prior webpack config file is that I have added esModule: false in svg-sprite-loader options and replaced MiniCssExtractPlugin with extract-text-webpack-plugin. Mind you that this solution is not ideal since this webpack plugin is deprecated.
here is my full webpack config file:
const path = require("path");
const webpack = require("webpack");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const CleanWebpackPlugin = require("clean-webpack-plugin");
const SpriteLoaderPlugin = require("svg-sprite-loader/plugin");
const ExtractTextPlugin = require("extract-text-webpack-plugin");
module.exports = {
mode: "development",
devtool: "source-map",
output: {
filename: "bundle.js",
path: path.resolve(__dirname, "dist")
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: "babel-loader",
options: {
sourceMap: true
}
}
},
{
test: /\.(s*)css$/,
use: ExtractTextPlugin.extract({
use: ["css-loader", "postcss-loader", "sass-loader"]
})
},
{
// html configuration
test: /\.html$/,
use: {
loader: "html-loader"
}
},
{
test: /\.svg$/,
use: [
{
loader: "svg-sprite-loader",
options: {
esModule: false,
extract: true,
spriteFilename: "sprite.svg"
}
}
]
},
{
// files configuration
test: /\.(jpg|jpeg|gif|png|woff|woff2)$/,
use: [
{
loader: "file-loader",
options: {
name: "[path][name].[ext]"
}
}
]
}
]
},
plugins: [
// all plugins used for compiling by webpack
new CleanWebpackPlugin(),
new HtmlWebpackPlugin({
title: "Style Guide",
template: path.resolve(__dirname, "src", "index.html")
}),
new ExtractTextPlugin({ filename: "app.css" }),
new SpriteLoaderPlugin()
]
};

Adding a csv file to a webpack build

I have placed a csv file in my assets folder for my react app, however, that file is not getting picked up and added to my dist build via webpack (the images are still added as assets to the build but the csv file is not). You can see my webpack build below. So how do I add a csv file to my dist build via webpack (the goal is for users of my app to be able to download this file)? Thanks!
webpack.dev.js
const merge = require('webpack-merge');
const common = require('./webpack.common.js');
const config = merge(common, {
mode: 'development',
devtool: 'inline-source-map',
devServer: {
contentBase: './dist',
historyApiFallback: true,
hot: true,
proxy: {
'/api': {
target: 'http://localhost:5001',
secure: false,
},
},
allowedHosts: [
'localhost',
'fatpandadev'
],
public: 'fatpandadev:8080'
},
});
module.exports = config;
webpack.common.js
const path = require('path');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const DIST_DIR = path.resolve(__dirname, "dist");
const SRC_DIR = path.resolve(__dirname, "src");
const config = {
entry: [
"babel-polyfill",
`${SRC_DIR}/app/index.js`,
`${SRC_DIR}/app/assets/stylesheets/application.scss`,
`${SRC_DIR}/app/components/index.scss`,
"font-awesome/scss/font-awesome.scss",
"react-datepicker/dist/react-datepicker.css",
"rc-time-picker/assets/index.css",
"react-circular-progressbar/dist/styles.css",
"#trendmicro/react-toggle-switch/dist/react-toggle-switch.css",
],
output: {
path: `${DIST_DIR}/app/`,
filename: "bundle.js",
publicPath: "/app/"
},
module: {
rules: [
{
enforce: "pre",
test: /\.js$/,
exclude: /node_modules/,
loader: "eslint-loader",
options: {
failOnWarning: false,
failOnError: true
}
},
{
test: /\.js$/,
include: SRC_DIR,
loader: 'babel-loader',
query: {
presets: ['react', 'stage-2']
}
},
{
test: /\.css$/,
use: [
MiniCssExtractPlugin.loader,
'css-loader'
]
},
{
test: /\.scss$/,
use: [
MiniCssExtractPlugin.loader,
'css-loader',
'sass-loader'
]
},
{
test: /\.(jpe?g|png|gif|svg)$/i,
loaders: ['file-loader?context=src/images&name=images/[path][name].[ext]', {
loader: 'image-webpack-loader',
query: {
mozjpeg: {
progressive: true,
},
gifsicle: {
interlaced: false,
},
optipng: {
optimizationLevel: 7,
},
pngquant: {
quality: '75-90',
speed: 3,
},
},
}],
exclude: path.resolve(__dirname, "node_modules"),
include: __dirname,
},
{
test: /\.woff2?(\?v=[0-9]\.[0-9]\.[0-9])?$/,
// loader: "url?limit=10000"
use: "url-loader"
},
{
test: /\.(ttf|eot|svg)(\?[\s\S]+)?$/,
use: 'file-loader'
},
{
test: /\.(txt|csv)$/,
use: [
{
loader: 'file-loader',
options: {}
}
]
},
]
},
plugins: [
new MiniCssExtractPlugin({
filename: "application.css"
})
]
};
module.exports = config;

(this answer is only referenced on the server side)
In addition to #PlayMa256,
On Server side(Nodejs runtime), you may need emitFile: true
{
test: /\.(txt|csv|mmdb)$/,
use: [
{
loader: 'file-loader',
options: {
name: "[path][name].[ext]",
emitFile: true,
},
},
],
},
Refer to this PR: https://github.com/webpack-contrib/file-loader/pull/135
In my opinion, file-loader way seem to better than copy-webpack-plugin way.
You can test like below:
import csvPath from './assets/data.csv'
console.log(csvPath) // assets/data.csv
Tested version:
$ cat node_modules/webpack/package.json | jq .version
"4.29.5"
$ cat node_modules/file-loader/package.json | jq .version
"3.0.1"

You might want to check the CopyWebpackPlugin if you have no need to process/parse the files, but only to copy them to your dist folder.
Copy Webpack Plugin
Copies individual files or entire directories to the build directory
Install
npm i -D copy-webpack-plugin
Usage
webpack.config.js
const CopyWebpackPlugin = require('copy-webpack-plugin')
const config = {
plugins: [
new CopyWebpackPlugin([ ...patterns ], options)
]
}
Patterns
A simple pattern looks like this
{ from: 'source', to: 'dest' }

{
test: /\.(txt|csv)$/,
use: [
{
loader: 'file-loader',
options: {}
}
]
}
You should import you csv file as you import your images too.

import your csv files using raw-loader,
{
test: /\.csv$/i,
use: 'raw-loader',
}

Webpack4: Process CSS and SCSS file with separate entry point

How can I target all CSS and SCSS files in a folder with an entry point, process them and then output the result into a single file in Webpack 4?
For JavaScript seems very straightforward: In the following example, I'm getting all files with js extension located in assets/js then they are transpiled and saved into /dist/bundle.js:
const path = require("path")
const glob = require("glob")
module.exports = {
devtool: 'source-map',
entry: glob.sync("./assets/js/*.js"),
output: {
path: path.resolve(__dirname, "./dist/js/"),
filename: 'bundle.js',
publicPath: '/dist'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader',
options: { presets: ["es2015"] }
}
}
]
},
}
I'd like to do the same (along with the previous example) but with CSS and SCSS files. I've tried:
const path = require("path")
const glob = require("glob")
const mcep = require("mini-css-extract-plugin")
module.exports = {
devtool: 'source-map',
entry: {
javascript: glob.sync("./assets/js/*.js"),
css: glob.sync("./assets/css/**/"),
},
output: {
path: path.resolve(__dirname, "./dist/js/"),
filename: 'bundle.js',
publicPath: '/dist'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader',
options: { presets: ["es2015"] }
}
},
{
test: /\.(sa|sc|c)css$/,
use: [
{
loader: mcep.loader
},
{
loader: "file-loader",
/*options: {
name: "bundle.css",
outputPath: "dist/css/"
}*/
},
{
loader: "style-loader" // creates style nodes from JS strings
},
{
loader: "css-loader" // translates CSS into CommonJS
},
{
loader: "sass-loader" // compiles Sass to CSS
}
]
}
]
},
plugins: [
new mcep({
filename: "./dist/css/[name].css",
chunks: ['css']
})
]
}
but it does not work. Again, I'd like to target all files within a specific folder, process them and ouput them into /dist/css/something.css, I don't want to import them into a js file.
Thanks

Vuejs / Webpack exclude json file from bundle

I have a no-sql database in the root of my project and I don't want webpack to include it in its bundle. Now I have to rebuild everytime the db gets updated. I'm using webpack 2.2.1. This is what I have:
var path = require('path')
var utils = require('./utils')
var config = require('../config')
var vueLoaderConfig = require('./vue-loader.conf')
function resolve (dir) {
return path.join(__dirname, '..', dir)
}
module.exports = {
entry: {
app: './resources/main.js'
},
output: {
path: config.build.assetsRoot,
filename: '[name].js',
publicPath: process.env.NODE_ENV === 'production'
? config.build.assetsPublicPath
: config.dev.assetsPublicPath
},
resolve: {
extensions: ['.js', '.vue', '.json'],
modules: [
resolve('resources'),
resolve('node_modules')
],
alias: {
'vue$': 'vue/dist/vue.common.js',
'src': resolve('resources'),
'assets': resolve('resources/assets'),
'components': resolve('resources/components')
}
},
module: {
rules: [
{
test: /\.(js|vue)$/,
loader: 'eslint-loader',
enforce: "pre",
include: [resolve('resources'), resolve('test')],
options: {
formatter: require('eslint-friendly-formatter')
}
},
{
test: /\.vue$/,
loader: 'vue-loader',
options: vueLoaderConfig
},
{
test: /\.js$/,
loader: 'babel-loader',
include: [resolve('resources'), resolve('test')]
},
{
test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
loader: 'url-loader',
query: {
limit: 10000,
name: utils.assetsPath('img/[name].[hash:7].[ext]')
}
},
{
test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
loader: 'url-loader',
query: {
limit: 10000,
name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
}
}
]
}
}
I tried to exclude it by adding it to the externals like so
externals: ['./../db.json'],
Or adding a rule like so
{
test: /\.json$/,
exclude: resolve('db.json')
}

as long as you require()/import it, you will always have to re-build, because webpack will convert it into a new file, as a webpack module.
What you really have to do is load it via AJAX from the browser after your app has started, with your AJAX tool of choice.