I am new to Webpack.
My team is using Golang for the server, and starting to use ReactJS + MobX on the front end. We use Webpack to bundle/transpile all the code into one bundle file per page. (It is multipage application.)
My PM has me looking into moving all this front-end code from static to a new folder called src, and to do the following:
setup the environment such that:
if running localhost, simply copy the files to that folder (we're debugging it)
else, minify the files to that folder (we don't want the end user to be able to reverse-engineer our stuff/see its source code)
Since Golang is running the server and not Webpack (our use case is merely the transpilation at development time), is there way that I can get Webpack to work like this?
NOTE: our entry files are not necessarily on the same level, but have path like static/js/[relative path of one or more levels]/entry.js
Use webpack merge you can do that
Basically you will need 3 file
Main webpack.config.js file
webpack.dev.js for dev enviroment
webpack.prod.js for production enviroment
Example: webpack.dev.js
const merge = require('webpack-merge');
const baseConfig = require('./webpack.config.js');
const webpack = require("webpack");
module.exports = merge(baseConfig, {
plugins: [
new webpack.DefinePlugin({
'process.env': {
'NODE_ENV': JSON.stringify('development'),
'BASE_URL': JSON.stringify('http://localhost:5000/')
}
})
],
watch: true
});
webpack.prod.js. You can see that I'm using some optimization packge in prod mode only like OptimizeCSSAssetsPlugin, CompressionPlugin, UglifyJsPlugin to uglify and gzip the file content to improve performance. You can adjust accordingly with your need.
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CompressionPlugin = require("compression-webpack-plugin");
const merge = require('webpack-merge');
const baseConfig = require('./webpack.config.js');
const webpack = require("webpack");
module.exports = merge(baseConfig, {
optimization: {
minimizer: [
new UglifyJsPlugin({
cache: true,
parallel: true,
sourceMap: false,
extractComments: 'all',
uglifyOptions: {
compress: true,
output: null
}
}),
new OptimizeCSSAssetsPlugin({
cssProcessorOptions: {
safe: true,
discardComments: {
removeAll: true,
},
},
})
]
},
plugins: [
new webpack.DefinePlugin({
'process.env': {
'NODE_ENV': JSON.stringify('production'),
'BASE_URL': JSON.stringify('a/')
}
}),
new CompressionPlugin({
test: /\.(js|css)/
}),
new UglifyJsPlugin(),
]
});
To run it simply use these 2 command in your package.json
"prod": "webpack -p --mode=production --config webpack.prod.js",
"start": "webpack --mode=development --config webpack.dev.js",
I'm trying to convert an angular app from gulp to webpack. in gulp I use gulp-preprocess to replace some variables in the html page (e.g. database name) depending on the NODE_ENV. What is the best way of achieving a similar result with webpack?
There are two basic ways to achieve this.
DefinePlugin
new webpack.DefinePlugin({
'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV || 'development')
}),
Note that this will just replace the matches "as is". That's why the string is in the format it is. You could have a more complex structure, such as an object there but you get the idea.
EnvironmentPlugin
new webpack.EnvironmentPlugin(['NODE_ENV'])
EnvironmentPlugin uses DefinePlugin internally and maps the environment values to code through it. Terser syntax.
Alias
Alternatively you could consume configuration through an aliased module. From consumer side it would look like this:
var config = require('config');
Configuration itself could look like this:
resolve: {
alias: {
config: path.join(__dirname, 'config', process.env.NODE_ENV)
}
}
Let's say process.env.NODE_ENV is development. It would map into ./config/development.js then. The module it maps to can export configuration like this:
module.exports = {
testing: 'something',
...
};
Just another option, if you want to use only a cli interface, just use the define option of webpack. I add the following script in my package.json :
"build-production": "webpack -p --define process.env.NODE_ENV='\"production\"' --progress --colors"
So I just have to run npm run build-production.
I investigated a couple of options on how to set environment-specific variables and ended up with this:
I have 2 webpack configs currently:
webpack.production.config.js
new webpack.DefinePlugin({
'process.env':{
'NODE_ENV': JSON.stringify('production'),
'API_URL': JSON.stringify('http://localhost:8080/bands')
}
}),
webpack.config.js
new webpack.DefinePlugin({
'process.env':{
'NODE_ENV': JSON.stringify('development'),
'API_URL': JSON.stringify('http://10.10.10.10:8080/bands')
}
}),
In my code I get the value of API_URL in this (brief) way:
const apiUrl = process.env.API_URL;
EDIT 3rd of Nov, 2016
Webpack docs has an example: https://webpack.js.org/plugins/define-plugin/#usage
new webpack.DefinePlugin({
PRODUCTION: JSON.stringify(true),
VERSION: JSON.stringify("5fa3b9"),
BROWSER_SUPPORTS_HTML5: true,
TWO: "1+1",
"typeof window": JSON.stringify("object")
})
With ESLint you need to specifically allow undefined variables in code, if you have no-undef rule on. http://eslint.org/docs/rules/no-undef like this:
/*global TWO*/
console.log('Running App version ' + TWO);
EDIT 7th of Sep, 2017 (Create-React-App specific)
If you're not into configuring too much, check out Create-React-App: Create-React-App - Adding Custom Environment Variables. Under the hood CRA uses Webpack anyway.
You can pass environment variables without additional plugins using --env
Webpack 2-4
webpack --config webpack.config.js --env.foo=bar
Webpack 5+ (without.)
webpack --config webpack.config.js --env foo=bar
Then, use the variable in webpack.config.js:
module.exports = function(env) {
if (env.foo === 'bar') {
// do something
}
}
Further Reading: Webpack 2.0 doesn't support custom command line arguments?
#2254
You can directly use the EnvironmentPlugin available in webpack to have access to any environment variable during the transpilation.
You just have to declare the plugin in your webpack.config.js file:
var webpack = require('webpack');
module.exports = {
/* ... */
plugins: [
new webpack.EnvironmentPlugin(['NODE_ENV'])
]
};
Note that you must declare explicitly the name of the environment variables you want to use.
To add to the bunch of answers personally I prefer the following:
const webpack = require('webpack');
const prod = process.argv.indexOf('-p') !== -1;
module.exports = {
...
plugins: [
new webpack.DefinePlugin({
process: {
env: {
NODE_ENV: prod? `"production"`: '"development"'
}
}
}),
...
]
};
Using this there is no funky env variable or cross-platform problems (with env vars). All you do is run the normal webpack or webpack -p for dev or production respectively.
Reference: Github issue
Since my Edit on the above post by thevangelist wasn't approved, posting additional information.
If you want to pick value from package.json like a defined version number and access it through DefinePlugin inside Javascript.
{"version": "0.0.1"}
Then, Import package.json inside respective webpack.config, access the attribute using the import variable, then use the attribute in the DefinePlugin.
const PACKAGE = require('../package.json');
const _version = PACKAGE.version;//Picks the version number from package.json
For example certain configuration on webpack.config is using METADATA for DefinePlugin:
const METADATA = webpackMerge(commonConfig({env: ENV}).metadata, {
host: HOST,
port: PORT,
ENV: ENV,
HMR: HMR,
RELEASE_VERSION:_version//Version attribute retrieved from package.json
});
new DefinePlugin({
'ENV': JSON.stringify(METADATA.ENV),
'HMR': METADATA.HMR,
'process.env': {
'ENV': JSON.stringify(METADATA.ENV),
'NODE_ENV': JSON.stringify(METADATA.ENV),
'HMR': METADATA.HMR,
'VERSION': JSON.stringify(METADATA.RELEASE_VERSION)//Setting it for the Scripts usage.
}
}),
Access this inside any typescript file:
this.versionNumber = process.env.VERSION;
The smartest way would be like this:
// webpack.config.js
plugins: [
new webpack.DefinePlugin({
VERSION: JSON.stringify(require("./package.json").version)
})
]
Thanks to Ross Allen
Just another answer that is similar to #zer0chain's answer. However, with one distinction.
Setting webpack -p is sufficient.
It is the same as:
--define process.env.NODE_ENV="production"
And this is the same as
// webpack.config.js
const webpack = require('webpack');
module.exports = {
//...
plugins:[
new webpack.DefinePlugin({
'process.env.NODE_ENV': JSON.stringify('production')
})
]
};
So you may only need something like this in package.json Node file:
{
"name": "projectname",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"debug": "webpack -d",
"production": "webpack -p"
},
"author": "prosti",
"license": "ISC",
"dependencies": {
"webpack": "^2.2.1",
...
}
}
Just a few tips from the DefinePlugin:
The DefinePlugin allows you to create global constants which can be configured at compile time. This can be useful for allowing different behavior between development builds and release builds. For example, you might use a global constant to determine whether logging takes place; perhaps you perform logging in your development build but not in the release build. That's the sort of scenario the DefinePlugin facilitates.
That this is so you can check if you type webpack --help
Config options:
--config Path to the config file
[string] [default: webpack.config.js or webpackfile.js]
--env Enviroment passed to the config, when it is a function
Basic options:
--context The root directory for resolving entry point and stats
[string] [default: The current directory]
--entry The entry point [string]
--watch, -w Watch the filesystem for changes [boolean]
--debug Switch loaders to debug mode [boolean]
--devtool Enable devtool for better debugging experience (Example:
--devtool eval-cheap-module-source-map) [string]
-d shortcut for --debug --devtool eval-cheap-module-source-map
--output-pathinfo [boolean]
-p shortcut for --optimize-minimize --define
process.env.NODE_ENV="production"
[boolean]
--progress Print compilation progress in percentage [boolean]
I found the following solution to be easiest to setup environment variable for Webpack 2:
For example we have a webpack settings:
var webpack = require('webpack')
let webpackConfig = (env) => { // Passing envirmonment through
// function is important here
return {
entry: {
// entries
},
output: {
// outputs
},
plugins: [
// plugins
],
module: {
// modules
},
resolve: {
// resolves
}
}
};
module.exports = webpackConfig;
Add Environment Variable in Webpack:
plugins: [
new webpack.EnvironmentPlugin({
NODE_ENV: 'development',
}),
]
Define Plugin Variable and add it to plugins:
new webpack.DefinePlugin({
'NODE_ENV': JSON.stringify(env.NODE_ENV || 'development')
}),
Now when running webpack command, pass env.NODE_ENV as argument:
webpack --env.NODE_ENV=development
// OR
webpack --env.NODE_ENV development
Now you can access NODE_ENV variable anywhere in your code.
I prefer using .env file for different environment.
Use webpack.dev.config to copy env.dev to .env into root folder
Use webpack.prod.config to copy env.prod to .env
and in code
use
require('dotenv').config();
const API = process.env.API ## which will store the value from .env file
My workaround for the webpack version "webpack": "^4.29.6" is very simple.
//package.json
{
...
"scripts": {
"build": "webpack --mode production",
"start": "webpack-dev-server --open --mode development"
},
}
you can pass --mode parameter with your webpack commnad then in webpack.config.js
// webpack.config.json
module.exports = (env,argv) => {
return {
...
externals: {
// global app config object
config: JSON.stringify({
apiUrl: (argv.mode==="production") ? '/api' : 'localhost:3002/api'
})
}
}
And I use baseurl in my code like this
// my api service
import config from 'config';
console.log(config.apiUrl) // like fetch(`${config.apiUrl}/users/user-login`)
To add to the bunch of answers:
Use ExtendedDefinePlugin instead of DefinePlugin
npm install extended-define-webpack-plugin --save-dev.
ExtendedDefinePlugin is much simpler to use and is documented :-)
link
Because DefinePlugin lacks good documentation, I want to help out, by saying that it actually works like #DEFINE in c#.
#if (DEBUG)
Console.WriteLine("Debugging is enabled.");
#endif
Thus, if you want to understand how DefinePlugin works, read the c# #define doucmentation. link
Since Webpack v4, simply setting mode in your Webpack config will set the NODE_ENV for you (via DefinePlugin). Docs here.
Here is a way that has worked for me and has allowed me keep my environment variables DRY by reusing a json file.
const webpack = require('webpack');
let config = require('./settings.json');
if (__PROD__) {
config = require('./settings-prod.json');
}
const envVars = {};
Object.keys(config).forEach((key) => {
envVars[key] = JSON.stringify(config[key]);
});
new webpack.DefinePlugin({
'process.env': envVars
}),
dotenv-webpack
A secure webpack plugin that supports dotenv and other environment variables and only exposes what you choose and use.
with some workaround with configuration based on defaults option to achieve that, once the package has .env.defaults file to as initial values for env variables you can use it for development and let .env for your production.
Usage
install the package
npm install dotenv-webpack --save-dev
Create a .env.defaults file
API_URL='dev_url/api/'
create a .env file leave it empty, let defaults works, update it on your deploy process
config webpack - webpack.config.js
new Dotenv({
defaults: true
})
dev environement test file.js
console.log(process.env.API_URL)
// Outputs: dev_url/api/
on build, update empty .env file
API_URL='prod_url/api/'
dotenv-webpack will use this to and override env.defaults
prod environement test file.js
console.log(process.env.API_URL)
// Outputs: prod_url/api/
dotenv-webpack
dotenv-defaults
I'm not a huge fan of...
new webpack.DefinePlugin({
'process.env': envVars
}),
...as it does not provides any type of security. instead, you end up boosting your secret stuff, unless you add a webpack to gitignore 🤷♀️ there is a better solution.
Basically with this config once you compile your code all the process env variables will be removed from the entire code, there is not going to be a single process.env.VAR up thanks to the babel plugin transform-inline-environment-variables
PS if you do not want to end up with a whole bunch of undefines, make sure you call the env.js before webpack calls babel-loader, that's why it is the first thing webpack calls. the array of vars in babel.config.js file must match the object on env.js. now there is only one mow thing to do.
add a .env file put all your env variables there, the file must be at the root of the project or feel free to add it where ever u want, just make sure to set the same location on the env.js file and also add it to gitignore
const dotFiles = ['.env'].filter(Boolean);
if (existsSync(dotFiles)) {
require("dotenv-expand")(require("dotenv").config((dotFiles)));
}
If you want to see the whole babel + webpack + ts get it from heaw
https://github.com/EnetoJara/Node-typescript-babel-webpack.git
and same logic applies to react and all the other 💩
config
---webpack.js
---env.js
src
---source code world
.env
bunch of dotFiles
env.js
"use strict";
/***
I took the main idea from CRA, but mine is more cooler xD
*/
const {realpathSync, existsSync} = require('fs');
const {resolve, isAbsolute, delimiter} = require('path');
const NODE_ENV = process.env.NODE_ENV || "development";
const appDirectory = realpathSync(process.cwd());
if (typeof NODE_ENV !== "string") {
throw new Error("falle and stuff");
}
const dotFiles = ['.env'].filter(Boolean);
if (existsSync(dotFiles)) {
require("dotenv-expand")(require("dotenv").config((dotFiles)));
}
process.env.NODE_PATH = (process.env.NODE_PATH || "")
.split(delimiter)
.filter(folder => folder && isAbsolute(folder))
.map(folder => resolve(appDirectory, folder))
.join(delimiter);
const ENETO_APP = /^ENETO_APP_/i;
module.exports = (function () {
const raw = Object.keys ( process.env )
.filter ( key => ENETO_APP.test ( key ) )
.reduce ( ( env, key ) => {
env[ key ] = process.env[ key ];
return env;
},
{
BABEL_ENV: process.env.ENETO_APP_BABEL_ENV,
ENETO_APP_DB_NAME: process.env.ENETO_APP_DB_NAME,
ENETO_APP_DB_PASSWORD: process.env.ENETO_APP_DB_PASSWORD,
ENETO_APP_DB_USER: process.env.ENETO_APP_DB_USER,
GENERATE_SOURCEMAP: process.env.ENETO_APP_GENERATE_SOURCEMAP,
NODE_ENV: process.env.ENETO_APP_NODE_ENV,
PORT: process.env.ENETO_APP_PORT,
PUBLIC_URL: "/"
} );
const stringyField = {
"process.env": Object.keys(raw).reduce((env, key)=> {
env[key]=JSON.stringify(raw[key]);
return env;
},{}),
};
return {
raw, stringyField
}
})();
webpack file with no plugins troll
"use strict";
require("core-js");
require("./env.js");
const path = require("path");
const nodeExternals = require("webpack-node-externals");
module.exports = env => {
return {
devtool: "source-map",
entry: path.join(__dirname, '../src/dev.ts'),
externals: [nodeExternals()],
module: {
rules: [
{
exclude: /node_modules/,
test: /\.ts$/,
use: [
{
loader: "babel-loader",
},
{
loader: "ts-loader"
}
],
},
{
test: /\.(png|jpg|gif)$/,
use: [
{
loader: "file-loader",
},
],
},
],
},
node: {
__dirname: false,
__filename: false,
},
optimization: {
splitChunks: {
automaticNameDelimiter: "_",
cacheGroups: {
vendor: {
chunks: "initial",
minChunks: 2,
name: "vendor",
test: /[\\/]node_modules[\\/]/,
},
},
},
},
output: {
chunkFilename: "main.chunk.js",
filename: "name-bundle.js",
libraryTarget: "commonjs2",
},
plugins: [],
resolve: {
extensions: ['.ts', '.js']
} ,
target: "node"
};
};
babel.config.js
module.exports = api => {
api.cache(() => process.env.NODE_ENV);
return {
plugins: [
["#babel/plugin-proposal-decorators", { legacy: true }],
["#babel/plugin-transform-classes", {loose: true}],
["#babel/plugin-external-helpers"],
["#babel/plugin-transform-runtime"],
["#babel/plugin-transform-modules-commonjs"],
["transform-member-expression-literals"],
["transform-property-literals"],
["#babel/plugin-transform-reserved-words"],
["#babel/plugin-transform-property-mutators"],
["#babel/plugin-transform-arrow-functions"],
["#babel/plugin-transform-block-scoped-functions"],
[
"#babel/plugin-transform-async-to-generator",
{
method: "coroutine",
module: "bluebird",
},
],
["#babel/plugin-proposal-async-generator-functions"],
["#babel/plugin-transform-block-scoping"],
["#babel/plugin-transform-computed-properties"],
["#babel/plugin-transform-destructuring"],
["#babel/plugin-transform-duplicate-keys"],
["#babel/plugin-transform-for-of"],
["#babel/plugin-transform-function-name"],
["#babel/plugin-transform-literals"],
["#babel/plugin-transform-object-super"],
["#babel/plugin-transform-shorthand-properties"],
["#babel/plugin-transform-spread"],
["#babel/plugin-transform-template-literals"],
["#babel/plugin-transform-exponentiation-operator"],
["#babel/plugin-proposal-object-rest-spread"],
["#babel/plugin-proposal-do-expressions"],
["#babel/plugin-proposal-export-default-from"],
["#babel/plugin-proposal-export-namespace-from"],
["#babel/plugin-proposal-logical-assignment-operators"],
["#babel/plugin-proposal-throw-expressions"],
[
"transform-inline-environment-variables",
{
include: [
"ENETO_APP_PORT",
"ENETO_APP_NODE_ENV",
"ENETO_APP_BABEL_ENV",
"ENETO_APP_DB_NAME",
"ENETO_APP_DB_USER",
"ENETO_APP_DB_PASSWORD",
],
},
],
],
presets: [["#babel/preset-env",{
targets: {
node: "current",
esmodules: true
},
useBuiltIns: 'entry',
corejs: 2,
modules: "cjs"
}],"#babel/preset-typescript"],
};
};
now 2020, i am face to same question, but for this old question, there are so many new answer, just list some of it:
this is webpack.config.js
plugins: [
new HtmlWebpackPlugin({
// 1. title is the parameter, you can use in ejs template
templateParameters:{
title: JSON.stringify(someting: 'something'),
},
}),
//2. BUILT_AT is a parameter too. can use it.
new webpack.DefinePlugin({
BUILT_AT: webpack.DefinePlugin.runtimeValue(Date.now,"some"),
}),
//3. for webpack5, you can use global variable: __webpack_hash__
//new webpack.ExtendedAPIPlugin()
],
//4. this is not variable, this is module, so use 'import tt' to use it.
externals: {
'ex_title': JSON.stringify({
tt: 'eitentitle',
})
},
the 4 ways only basic, there are even more ways that i believe. but i think maybe this 4ways is the most simple.