Develop Reference

Webpack 5 IgnorePlugin - Not ignoring JS file from output on CSS files only?

I am trying to use the Webpack's IngorePlugin. I am using my Webpack file only to create a CSS file. On build, it outputs a JS file. But I don't want that. Tried ignoring JS files but still outputs it.
new webpack.IgnorePlugin(/^\.\/js\/(?!admin)/),
Outputs in the ROOT folder. So I want to disable all JS files from the output in the root folder. "admin" is the file being created.
How can I do this?

To properly answer your question, it'd be helpful if you posted a link to the full WP config file and an example of the file that's being processed.
Also, you mentioned you're only using WP to create a CSS file, does that mean you're just trying to use something like SASS, Stylus, Less, etc? If so, you could probably just set up a package.json script to compile your CSS without WP.
For example, if you have a .scss file, you could install node-sass, and create a simple Node script to compile what file you pass in as an arg.
bin/
- build-css.js
src/
- styles.sass
Within build-css.js
#!/usr/bin/env node
const { basename, resolve } = require('path');
const sass = require('node-sass');
const [...files] = process.argv.slice(2);
if (files.length) {
files.forEach((relativeFilePath) => {
const fileName = basename(relativeFilePath, '.scss');
sass.render(
{
file: resolve(__dirname, relativeFilePath),
outFile: resolve(__dirname, `./public/css/${fileName}.css`),
},
(err, result) => { console.log(err); }
);
});
}
else {
console.log('No files were provided to process');
}
Within package.json
"scripts": {
"build:css": "node ./bin/build-css.js"
}
The above has the benefit of giving you the control of how your files are processed at a more granular level, and you're only locked in to any SCSS changes, instead of Webpack and SCSS.
If you're using WP for it's file watching capabilities, you could instead wire up chokidar to run the new script when you change files.

Add a JavaScript file to webpack build without using Manifest

I have a plain webpack app, index.html, main.js, that builds just fine.
I also have a self contained javascript file iframe.js, to be added to 3rd party sites that will add an iframe container referencing the webpack app:
<iframe src="https://webpack-app-domain.com/index.html">
I would like the webpack build to process iframe.js with process.env substitutions of the sort:
<%= process.env.IFRAME_URL %>
and let babel convert it to ES5 javascript and minify the output for production, but I do NOT want iframe.js to be part of the Manifest nor other dependencies introduced into the script.
It is not a webpack "entry".
If I place it in the /static folder it will get deployed, unaltered, but I cannot then customise it with any process.env variables, nor transpile, nor minify it.
If I add it as a separate webpack "entry", it gets transpiled and minified, but it also gets wrapped in a manifest function call: webpackJsonp(), yet I need the javascript to be self-contained.
How can I process this javascript file with the webpack build to satisfy my requirements?
Edit: Thanks for your replies. I applied an inline transform with the CopyWebpackPlugin to achieve my desired outcome:
const UglifyJS = require('uglify-js')
const babel = require("babel-core")
...
new CopyWebpackPlugin([
{
from: 'src/iframe.js',
to: '',
transform(content, path) {
let js = content.toString('utf8')
js = js.replace(new RegExp("process.env.IFRAME_URL", 'g'), env.IFRAME_URL)
.replace(new RegExp("process.env.ROOT_API", 'g'), env.ROOT_API)
let t = babel.transform(js, {
presets: ["env"]
})
if (t.error) throw t.error
js = t.code
let min = UglifyJS.minify(js)
if (min.error) throw min.error
js = min.code.toString()
return Buffer.from(js)
},
},
])
I'm not sure if this is the most elegant way but it does the job. It's duplicating the plugin pipeline that's otherwise bypassed.

I fail to see where manifest.json relates to this question.
My answer: Use externals paired with a custom command for a separate webpack build. It's not uncommon to have more than one compilation step in a project.
If you are using package.json, then you could add this to the scripts section, and if you are using command line then just make shell script or something.
NODE_ENV=some_env webpack --config webpack.iframe.config.js --progress --colors -d --output-path 'assets' --display verbose
Then you're free to separate the dependency build from the project build, and include the results as an external in your main project.

Have you tried using using copy-webpack-plugin?
This way you would run your normal build in parallel to copying a single file.
You can use the transform method to replace the contents of the file for process.env.* and output it to the destination you want.
const CopyPlugin = require('copy-webpack-plugin');
module.exports = {
plugins: [
new CopyPlugin([
{
from: 'src/*.png',
to: 'dest/',
transform(content, path) {
return optimize(content);
},
},
]),
],
};

ES6 Dynamic Imports using Webpack and Babel

I've been using Webpack for my ES6 JS project and has been going well until I started to play with dynamic imports.
What I had that worked (router.js):
import { navigo } from "Navigo"; // router
import { clients } from "Controllers/clients.js";
const navigo = new Navigo();
navigo_router.on({
'/clients': () => {
clients.init();
}
});
But the more pages/routes I add, the more imports get stacked up in the head of the module. This is a relatively large app and I have a lot of pages/routes to add and therefore I need to load them dynamically to reduce the size of the initial page load.
So, following Webpack's documentation for dynamic imports, I tried the following which loads the controller module only when the relative route is called:
import { navigo } from "Navigo"; // router
const navigo = new Navigo();
navigo_router.on({
'/clients': () => {
import("Controllers/clients.js").then((clients) => {
clients.init();
});
}
});
But saving this in my editor resulted in a Babel transpiling error; SyntaxError: 'import' and 'export' may only appear at the top level, and clients.init() is not being called when tested in browser.
After a bit of reading, I discovered I needed a Babel plugin to transpile dynamic import() to require.ensure. So, I installed the plugin using the following command:
npm install babel-plugin-dynamic-import-webpack --save-dev
And declared the plugin in my babel.rc file
{ "plugins": ["dynamic-import-webpack"] }
After installing the plugin, the transpiling error disappeared and checking my transpiled code I found that the dynamic import()s has in fact been changed to require.ensure as expected. But now I get the following browser errors when testing:
Error: Loading chunk 0 failed.
Stack trace:
u#https://<mydomain.com>/js/app.bundle.js:1:871
SyntaxError: expected expression, got '<' 0.app.bundle.js:1
Error: Loading chunk 0 failed.
I didn't understand why it was referencing 0.app.bundle.js with the 0. prefix, so I checked my output/dist folder and I now have a new file in there called 0.app.bundle.js:
0.app.bundle.js 1,962bytes
app.bundle.js 110,656bytes
I imagine this new bundled file is the dynamically imported module, clients.js.
I only added dynamic importing to that one route and have left all the other routes as they were. So, during testing, I can view all routes except that one /clients route that now throws the above errors.
I'm totally lost at this point and hoped somebody could help push me over the finish line. What is this new file 0.app.bundle.js and how am I supposed to be using it/including it in my application?
I hope I've explained myself clearly enough and look forward to any responses.

I managed to fix my own problem in the end, so I will share what I discovered in an answer.
The reason the chunk file wasn't loading was because Webpack was looking in the wrong directory for it. I noticed in the Network tab of my developer console that the the chunk file/module was being called from my root directory / and not in /js directory where it belongs.
As per Webpack's documentation, I added the following to my Webpack config file:
output: {
path: path.resolve(__dirname, 'dist/js'),
publicPath: "/js/", //<---------------- added this
filename: 'app.bundle.js'
},
From what I understand, path is for Webpack's static modules and publicPath is for dynamic modules.
This made the chunk load correctly but I also had further issues to deal with, as client.init() wasn't being called and yielded the following error:
TypeError: e.init is not a function
To fix this, I also had to change:
import("Controllers/clients.js").then((clients) => {
clients.init();
});
To:
import("Controllers/clients.js").then(({clients}) => {
clients.init();
});
Note the curly braces in the arrow function parameter.
I hope this helps somebody else.

For debugging, you need to do
import("Controllers/clients.js").then((clients) => {
console.log(clients);
});
maybe working
import("Controllers/clients.js").then((clients) => {
clients.default.init();
});

WebPack execute function before build starts

I need to execute one JavaScript function before the Webpack starts its building process. The function just takes .scss files and concatenate them into one.
After that Webpack should take the result file. Is there an option to do that?
At the moment I run the function before the module.exports in webpack.config.js, but it seems that its not synchronous operation. Module.exports execute before the concat() function ends and Webpack can't find .scss file.
function concat(opts) {
(...)
}
concat({ src : styles, dest : './css/style.scss' });
module.exports = [
(...)
]

It seems a little bit odd to concat scss files before running Webpack as those kind of operations are usually handled by Webpack itself.
That being said, there's a few way of solving this.
The most obvious way would be to extract the concat parts to a separate file (e.g. prepare.js) and then run start the build process by running something along this line: node prepare.js && webpack. That'll first run prepare and if that exits without error webpack will be run. Usually that'll be added to the scripts part of your package.json, e.g.
"scripts": {
"build": "node prepare.js && webpack"
}
To achieve the same but in a more Webpack integrated way you could do the same thing where you extract the concat part to a separate file and then let Webpack execute that file, before build starts, with the help of Webpack Shell Plugin, e.g.
const WebpackShellPlugin = require('webpack-shell-plugin');
module.exports = {
...
plugins: [
new WebpackShellPlugin({
onBuildStart:['node prepare.js']
})
],
...
}

You can add any code at any phase of the building, using the Compiler Hooks.
The compile hook is called before (and every time) the compilation begins, so you probably want to use that:
config = {
//...
plugins: [
{
apply: (compiler) => {
compiler.hooks.compile.tap("MyPlugin_compile", () => {
console.log("This code is executed before the compilation begins.");
});
},
},
],
//...
};

Simple solution to share modules loaded via NPM across multiple Browserify or Webpack bundles

Pulling my hair out here looking for a simple solution to share code, required via NPM, across multiple Browserify or Webpack bundles. Thinking, is there such a thing as a file "bridge"?
This isn't due to compile time (I'm aware of watchify) but rather the desire to extract out all of my vendor specific libs into vendor.js so to keep my app.js filesize down and to not crash the browser with massive sourcemaps. Plus, I find it way cleaner should the need to view the compiled js arise. And so:
// vendor.js
require('react');
require('lodash');
require('other-npm-module');
require('another-npm-module');
Its very important that the code be loaded from NPM as opposed to Bower, or saved into some 'vendor' directory in order to be imported via a relative path and identified via a shim. I'd like to keep every library reference pulled via NPM except for my actual application source.
In app.js I keep all of my sourcecode, and via the externals array, exclude vendor libraries listed above from compilation:
// app.js
var React = require('react');
var _ = require('lodash');
var Component = React.createClass()
// ...
And then in index.html, I require both files
// index.html
<script src='vendor.js'></script>
<script src='app.js'></script>
Using Browserify or Webpack, how can I make it so that app.js can "see" into those module loaded via npm? I'm aware of creating a bundle with externals and then referencing the direct file (in, say, node_modules) via an alias, but I'm hoping to find a solution that is more automatic and less "Require.js" like.
Basically, I'm wondering if it is possible to bridge the two so that app.js can look inside vendor.js in order to resolve dependencies. This seems like a simple, straightforward operation but I can't seem to find an answer anywhere on this wide, wide web.
Thanks!

Listing all the vendor files/modules and using CommonChunkPlugin is indeed the recommended way. This gets pretty tedious though, and error prone.
Consider these NPM modules: fastclick and mprogress. Since they have not adopted the CommonJS module format, you need to give webpack a hand, like this:
require('imports?define=>false!fastclick')(document.body);
require('mprogress/mprogress.min.css');
var Mprogress = require('mprogress/mprogress.min.js'),
Now assuming you would want both fastclick and mprogress in your vendor chunk, you would probably try this:
module.exports = {
entry: {
app: "./app.js",
vendor: ["fastclick", "mprogress", ...]
Alas, it doesn't work. You need to match the calls to require():
module.exports = {
entry: {
app: "./app.js",
vendor: [
"imports?define=>false!fastclick",
"mprogress/mprogress.min.css",
"mprogress/mprogress.min.js",
...]
It gets old, even with some resolve.alias trickery. Here is my workaround. CommonChunkPlugin lets you specify a callback that will return whether or not you want a module to be included in the vendor chunk. If your own source code is in a specific src directory, and the rest is in the node_modules directory, just reject the modules based on their path:
var node_modules_dir = path.join(__dirname, 'node_modules'),
app_dir = path.join(__dirname, 'src');
module.exports = {
entry: {
app: "./app.js",
},
output: {
filename: "bundle.js"
},
plugins: [
new webpack.optimize.CommonsChunkPlugin(
/* chunkName= */"vendor",
/* filename= */"vendor.bundle.js"
function (module, count) {
return module.resource && module.resource.indexOf(app_dir) === -1;
}
)
]
};
Where module.resource is the path to the module being considered. You could also do the opposite, and include only the module if it is inside node_modules_dir, i.e.:
return module.resource && module.resource.indexOf(node_modules_dir) === 0;
but in my situation, I'd rather say: "put everything that is not in my source source tree in a vendor chunk".
Hope that helps.

With webpack you'd use multiple entry points and the CommonChunkPlugin.
Taken from the webpack docs:
To split your app into 2 files, say app.js and vendor.js, you can require the vendor files in vendor.js. Then pass this name to the CommonChunkPlugin as shown below.
module.exports = {
entry: {
app: "./app.js",
vendor: ["jquery", "underscore", ...],
},
output: {
filename: "bundle.js"
},
plugins: [
new webpack.optimize.CommonsChunkPlugin(
/* chunkName= */"vendor",
/* filename= */"vendor.bundle.js"
)
]
};
This will remove all modules in the vendor chunk from the app chunk. The bundle.js will now contain just your app code, without any of it’s dependencies. These are in vendor.bundle.js.
In your HTML page load vendor.bundle.js before bundle.js.
<script src="vendor.bundle.js"></script>
<script src="bundle.js"></script>

// vendor anything coming from node_modules
minChunks: module => /node_modules/.test(module.resource)
Source: https://github.com/webpack/webpack/issues/2372#issuecomment-213149173