Blog Post : https://medium.com/@ardatan/meteor-with-webpack-in-2018-faster-compilation-better-source-handling-benefit-from-bc5ccc5735ef

Meteor-Webpack provides you a development environment that integrates modern web bundler Webpack, and modern perfect full-stack JavaScript framework Meteor.

You need just one atmosphere package to start; ardatan:webpack

This project includes some examples with popular Frontend frameworks and a compiler package that replaces Meteor's bundler with modern web project bundler Webpack. You have to create a webpack.config.js file that has the compilation configurations for both client and server code. You are to free to choose the directory structure in your project, Webpack will compile your project regarding to your entry definition.

Meteor-Webpack would make you feel you are using Webpack CLI. Just use same cases in Webpack's own documentation.

Meteor-Webpack can resolve any atmosphere packages and Meteor modules like you are using without Meteor-Webpack

• Vanilla
• Angular
• React
• Vue

• Faster compilation thanks to Webpack good caching during compilation
• ES2015 Modules support instead of loading modules on runtime like Meteor's bundle does in CommonJS way, because Meteor only converts ES2015 import syntax,import module from 'module',to CommonJS import syntax; const module = require('module').
• Tree-shaking for smaller final production bundle
• You can migrate your existing Webpack project to Meteor easily.
• You can use your existing Webpack loaders and plugins without a great modification including the ones don't exist as an atmosphere package.
• Hot Module Replacement without reloading in each compilation using Webpack Dev Middleware together with Meteor's connect-compatible HTTP Server
• HMR is available for server-side code, so your re-compiled server-side code will be replaced in 'already running' server without restart. So, the recompilation of server-side code takes less time than regular Meteor bundler's.
• Comparisons with other bundlers are explained here.

Regular Meteor Bundler uses babel which tranpiles your ES2015 syntax to ES5 even imports to CommonJS which creates some limitation for you. For instance, you cannot use ES2015 modules, then you need to import UMD modules which would probably contain unused submodules of this module. Despite you can use atmosphere packages with Meteor-Webpack, you don't need to add extra atmosphere packages for sass, typescript and others' compilation. For an extra compiler such as sass, less and pug etc; you can just install necessary webpack loader plugins, and add them into webpack.config.js. Meteor-Webpack runs exactly same way with webpack-dev-server.

As in its documentation; meteor-client-bundler is a module bundler which will take a bunch of Atmosphere package and put them into a single module, so we can load Meteor's client scripts regardless of what framework we're using to run our server. But you cannot use this client bundle with Server Side Rendering, and you must have two different projects which run on two different servers. With Meteor-Webpack, you can extract webpack.config.js from Angular CLI, create-react-app and any other CLI tools', then easily use it with Meteor.

• Remove existing compiler packages; meteor remove ecmascript es5-shim static-html
• If you are using Meteor entry points, you have to remove them from your package.json

"meteor": {
  "mainModule": {
    "client": "client/main.js",
    "server": "server/main.js"
  }
}

• You have to install webpack and necessary plugins with your favorite package manager; yarn or npm
• Add Meteor package webpack by the command meteor add ardatan:webpack
• Create webpack.config.js, and define entry module which is necessary for webpack.
• If you have seperate client and server codes, you have to declare two configurations like we have in our example.

• You have to add target field by node value in the configuration object you want to use as server's;

    const clientConfig = {
        //...
    }
    const serverConfig = {
        //...
        target: 'node',
    }

• If you are using Meteor's package imports such as import { Meteor } from 'meteor/meteor', import { Mongo } from 'meteor/mongo' and also non-global package references such as import { publishComposite } from 'meteor/reywood:publish-composite'. You have to install webpack-meteor-externals npm package, and add it to both client and server entries in webpack.config.js.
• If you are using all of them by their global references without imports, you don't need that package.

    meteor npm install webpack-meteor-externals --save-dev

    const meteorExternals = require('webpack-meteor-externals');
    //...
    externals: [
        meteorExternals()
    ]
    //...

• If you have an existing meteor app and do not want to change the pathnames from '/imports/...' to relative paths, use the following in your webpack.config.js

    //...
    resolve: {
        modules: [
          path.resolve(__dirname, 'node_modules'),
          path.resolve(__dirname, './'), // enables you to use 'imports/...' instead of '/imports/...'
        ],
        alias: {
          '/imports': path.resolve(__dirname, './imports'),
          '/ui': path.resolve(__dirname, './ui'),
          // ... and any other directories you might have
        }
    }
    //...

If you want to use Webpack's Development Server instead of Meteor's, you have to add devServer field in the client configuration;

    devServer: {}

then you have to add another atmosphere package to packages;

    meteor add ardatan:webpack-dev-middleware

NOTE Make sure ardatan:webpack-dev-middleware is at the bottom of your .packages list for the best compatibility with other Meteor packages.

don't forget to install webpack-dev-middleware package from NPM;

    meteor npm install webpack-dev-middleware --save-dev

• Install webpack-node-externals

    meteor npm install webpack-node-externals --save-dev

• Add externals into the server configuration in webpack.config.js

    externals: [nodeExternals()], // in order to ignore all modules in node_modules folder

• Process is the same with Webpack; so you have to just change your client and server configuration;

• Add hot field for both client and server which is true,

    devServer: {
        hot: true
    }

• and add the necessary plugin only for client; do not add this plugin for server, hot: true is enough for server-side HMR!

    plugins: {
        new webpack.HotModuleReplacementPlugin()
    }

• Then install webpack-dev-middleware,

• Install client-side HMR middleware webpack-hot-middleware in your project

• Install server-side HMR middleware webpack-hot-server-middleware in your project

• Meteor's bundler may restart your server which is not good for HMR's working process; so we need to disable it by adding .meteorignore on the root with the following content;

    *
    !.meteor/
    !node_modules/
    !webpack.config.js

• Meteor's server-render will work as expected if you use webpack to include HTML via HtmlWebpackPlugin. Important: Be sure that server-render is listed BELOW webpack-dev-server in meteor/packages

• You can use WebAppInternals.registerBoilerplateCallback to dynamically change the CSS and JS served to visitors via data.js and data.css. In order to use this feature with webpack, you must set inject: false on HtmlWebpackPlugin and set the environment variable DYNAMIC_ASSETS=true.

meteor deploy command doesn't set NODE_ENV=production environment variable. That's why, webpack compiler recognizes that it is still a development build. You have two options to fix issue;

• You have to provide GALAXY_NODE_OPTIONS=--production to make webpack recognize that it is a production build. or

• Create a seperate configuration file for webpack which doesn't contain development settings such as devServer, and includes UglifyJs plugins. Then, set environment variable WEBPACK_CONFIG_FILE=<filename>.

• Using meteor test requires the option --test-app-path $(pwd)/.meteortest. This will run the test inside the .meteortest directory in your project. Normally, meteor test runs a test version of the application inside your /tmp directory, but webpack needs to be able to access the project's node_modules folder.

• You may also run into permissions issues after the .meteortest folder is created. I recommend adding rm -r .meteortest to the beginning of your test command.

• All DDP connections are closed when the dev server recompiles in test mode. This will trigger testing libraries that use DDP (Chimpy) to re-run if they are in watch mode.