@untool/webpack

 

@untool/webpack is the largest and most complex of untool's core packages. It contains half of its total lines of code and provides both a preset and a core mixin. It provides a comprehensive, but rather minimal Webpack setup as a basis for your own configurations.

Based on @untool/express, it also features development and production servers. The former even comes with hot module replacement (HMR).

During application startup, @untool/webpack runs a check to determine if Webpack is installed multiple times. If you see warnings telling you that this is the case, you will want to make sure you get rid of these duplicates, as they will almost certainly break things in interesting ways.

Installation

$ yarn add @untool/webpack # OR npm install @untool/webpack

CLI

build

This is the most basic of @untool/webpack's commands - and it simply performs a Webpack build according to its arguments and configuration. It will not only start an usual browser build, but also one for the server-side version of your application.

Whether it uses said server-side build to generate static HTML pages depends on the arguments it is being called with - and it works best in tandem with @untool/express' serve command;

$ un build -ps && un serve -ps

Arguments

-p / --production

If un build is called with the production argument, untool itself sets the shell environment variable $NODE_ENV to "production". This variable is generally used in lots of places, for example to fine-tune @untool/webpack's Webpack configurations.

$ un build -p # OR un build --production

This is equivalent to manually setting $NODE_ENV before calling the actual command. Use whatever works best in your specific setting.

$ NODE_ENV=production un build

-s / --static (deprecated)

In static mode, static HTML pages will be generated for the locations configured for your application. In no-static mode, server.js and stats.json files will be created instead.

Note: Static rendering is deprecated and will be removed in a future major release.

develop

Using this command, you can start a full-featured development server that is as similar to a production system as possible. It does, however, ensure the browser and server versions of your application are being recompiled and redeployed whenever you change your code.

$ un develop

start

This is probably the untool command your will use most of the time - we certainly do. It is, essentially, just a shorthand for other untool commands.

$ un start # OR un start -p

Arguments

-p / --production

If called in production mode, un start will first perform a build and start an express server afterwards. Otherwise it will start a development server. un start -ps is thus equivalent to un start -ps && un serve -ps, while un start -s is equivalent to un develop -s. All arguments are used as documented with those other commands.

Of course, once again, you can also manually set $NODE_ENV.

$ NODE_ENV=production un start

-s / --static

In static mode, static HTML pages will be generated for the locations configured for your application.

API

@untool/webpack provides a couple of configurable exports for your convenience: mixin hooks marked with 'callable' below can be called like in the following example example:

const { build } = require('@untool/webpack');
build();

If you need to provide config overrides or options to these kinds of calls, you can do so like in the next example.

const { configure } = require('@untool/webpack');
const { build } = configure(configOverrides, options);
build();

The above example is functionally equivalent to directly working with @untool/core's bootstrap export.

configureBuild(webpackConfig, loaderConfigs, target) (sequence)

If you implement this mixin hook in your @untool/core core mixin, you will be able to modify the different Webpack configs untool uses in any way you like.

In addition to the actual webpackConfig, which, by the way, your implementation is expected to return, you will receive an object containing all loaderConfigs and a target argument. This last argument can be build, develop, or node.

const { Mixin } = require('@untool/core');

module.exports = class MyMixin extends Mixin {
  configureBuild(webpackConfig, loaderConfigs, target) {
    webpackConfig.resolve.extensions.push('.ftw');
  }
};

You can use whatever mechanism you like to modify the complicated structures Webpack configs unfortunately have to be. For convenience, loaderConfigs contains the following properties for you to inspect and modify specific loader configs directly:

Property	Explanation
jsLoaderConfig	babel-loader config
urlLoaderConfig	url-loader config
fileLoaderConfig	file-loader config
allLoaderConfigs	Array of loader configs passed to oneOf module loader rule

Caveat: please be advised that, while we strive to provide very stable webpackConfig and loaderConfigs arguments, these may change in subtle ways between minor versions of @untool/webpack. For example, specific loader options may stop working. Additionally, other mixins may alter these arguments in relevant ways, so code accordingly.

inspectBuild(stats, config) (sequence)

If you want to programmatically determine whether a build went well, your mixin can implement this method. It will be called with a Webpack stats object and the actual configuration used for the specific build you are inspecting.

build() (callable)

If you want to intialize a build of your application, you can do so using this utility mixin method. It returns a Promise resolving to a stats object.

This method is also exported so that you can use it in your own, non-mixin code. Import it like so: import { build } from '@untool/webpack';. In this mode, it also accepts another argument, options, which you can pass any CLI argument to.

clean() (callable)

Using this utility mixin method, you can delete your buildDir and all of its contents. It returns a Promise.

This method is also exported so that you can use it in your own, non-mixin code. Import it like so: import { clean } from '@untool/webpack';. In this mode, it also accepts another argument, options, which you can pass any CLI argument to.

getWebpackBuildConfig(target) (callable)

Returns the webpack config for the production build after configureBuild has been applied. target argument can be browser or none and will determine which mixins should be bundled.

This method is also exported so that you can use it in your own, non-mixin code. Import it like so: import { getWebpackBuildConfig } from '@untool/webpack';. In this mode, it also accepts another argument, options, which you can pass any CLI argument to.

getWebpackDevelopConfig(target) (callable)

Returns the webpack config for the development build after configureBuild has been applied. target argument can be browser or none and will determine which mixins should be bundled.

This method is also exported so that you can use it in your own, non-mixin code. Import it like so: import { getWebpackDevelopConfig } from '@untool/webpack';. In this mode, it also accepts another argument, options, which you can pass any CLI argument to.

getWebpackNodeConfig(target) (callable)

Returns the webpack config for the server-side Node.js build after configureBuild has been applied. target argument can be server or none and will determine which mixins should be bundled.

This method is also exported so that you can use it in your own, non-mixin code. Import it like so: import { getWebpackNodeConfig } from '@untool/webpack';. In this mode, it also accepts another argument, options, which you can pass any CLI argument to.

Settings

Property	Type	Default
browsers	[string]	['defaults']
node	string	'current'
locations	[string]	[]
basePath	string	''
assetPath	string	'<basePath>'
buildDir	string	'<distDir>'
serverDir	string	'<rootDir>/node_modules/.cache/untool'
serverFile	string	'server.js'
statsFile	string	'stats.json'

browsers

This is a browserslist configuration that is being used and Babel's preset-env to determine what language features need to be transpiled and/or polyfilled for your target platforms.

{
  "browsers": ["last 1 Chrome versions"]
}

node

This is the target Node.js version Babel's preset-env transpiles features for. Usually you will want to keep its default, as it is best practice to develop and build your application on the same Node version as you run in production.

{
  "node": "12.13"
}

locations

Using this setting, you can define the locations used for prerendering of static HTML pages at build time. Simply list all URL paths you want to prerender and perform a build in static mode, e.g. by running un build -ps.

Locations are treated as relative to your configured basePath: you will not have to add it as a prefix to your locations yourself.

{
  "locations": ["/foo", "/bar"]
}

Note: the prerendering of static HTML pages has been deprecated and will be removed in the next major release of untool.

basePath

This is the URL base path, i.e. subfolder, your application will be served from. If set, this folder will be created in your buildDir during static builds.

{
  "basePath": "<name>"
}

assetPath

This is the URL base path, i.e. subfolder, your application's assets will be served from. If set, this folder will be created in your buildDir at build time.

{
  "assetPath": "<basePath>/assets"
}

buildDir

Path of your browser build output. By default, this folder is usually removed before building. Make sure the contents of this folder can be served by your webserver.

{
  "buildDir": "<rootDir>/build"
}

serverDir

Path of your server build output. It will only be used in production, non-static mode. By default, this folder is located inside your node_modules folder and it is usually removed before building.

{
  "serverDir": "<buildDir>"
}

serverFile

Path of your server output file, relative to serverDir. It will only be generated in production, non-static mode and is being used internally.

{
  "serverFile": "server.js"
}

statsFile

Path of your stats file, relative to serverDir. It will only be generated in production, non-static mode and is being used internally.

{
  "assetFile": "stats.json"
}