To Upgrade...

npm remove laravel-mix
npm install laravel-mix@4.0.0

After upgrading, if you encounter any vue-template-compiler issues, this is related to the fact that your installed version numbers of vue and vue-template-compiler must be identical. Update one or both to fix this issue.

New

• Faster compiles
• Faster npm installs.
• Upgraded to webpack 4
• Upgraded to vue-loader 15
• Upgraded to Babel 7
• Automatic vendor extraction. If you call mix.extract() with zero arguments, all vendor dependencies (any package from node_modules/ that you pull in) will automatically be extracted. Nifty!
• CSS minification (via cssnano) options may be provided 887808f8aea03b5dabc9e7350b66ee01a52e1610
• PostCSS plugins may be passed to mix.sass/less/stylus() on a per-call basis. This means you may provide unique PostCSS plugins for each mix.sass() call, if desired. 88690a2f770c071dc8160127c42a4f44decf2b56
• Switched JS optimizing/minification from Uglify to Terser. 5fb180e6e430e99b740a4bce330669cdd8fda29c
• Switched from node-sass to Dart Sass. While this comes with a small increased compile-time cost, the benefit is faster and more reliable npm installs. 320cecbdb77e222e32903219905d0d8f3754c5ff
• Improved Babel config merging strategy. You may now override or tweak any default Babel plugins and presets provided through Mix by creating a .babelrc file in your project root. 83f5052eb32c498a90edace47402d66eaf80f4b7

Bugfixes

• All npm audit alerts have been fixed, thanks to the upgrade to webpack 4.

Notes

• If your project heavily uses JavaScript dynamic imports, you may need to hold off until the release of webpack 5 early next year. There are known compile issues related to this that we cannot fix until then. Once webpack 5 is out, Mix will be updated shortly after. If you're unfamiliar with dynamic imports, then this very likely won't affect your project.
• Sass support is now an on-demand dependency. In prior versions of Mix, the node-sass and sass-loader dependencies were included out of the box, regardless of whether your project required Sass compilation or not. To help improve install times, these two dependencies will now be installed on-demand if, and only if, your project specifies Sass compilation with mix.sass(). The first time you run npm run dev, the dependencies will be installed and saved to your dev-dependencies list. 5b7a438bcf53bc87ccc08da09b1e816a6088dec8

Breaking

Importing ES Modules

Important: As part of the vue-loader 15 updates, if your code uses the CommonJS syntax for importing EcmaScript modules, you'll need to append .default, like so:

Before

Vue.component('example-component', require('./components/ExampleComponent.vue'));

After

// Option 1: Add .default

Vue.component('example-component', require('./components/ExampleComponent.vue').default);

// Option 2 (Recommended): Switch to EcmaScript imports.

import ExampleComponent from './components/ExampleComponent.vue';

Vue.component('example-component', ExampleComponent);

Babel 7 Updates

Important: Now that Mix has been updated to support Babel 7, you may need to address a few Babel-specific breaking changes. If your project pulls in extra Babel plugins that Mix does not provide out of the box, you'll need to update your local dependencies.

1. The naming convention for official Babel plugins has changed. They are now scoped under the @babel namespace. As such, in your package.json file, change all occurrences of "babel-plugin-[name]": "6.x" to "@babel/plugin-[name]": "7.x"
2. If you've created a .babelrc file in your project, update all plugin name references. For example, update "plugins": ["babel-plugin-transform-object-rest-spread"] to "plugins": ["@babel/plugin-proposal-object-rest-spread"]

Node Sass to Dart Sass

As part of our switch from node-sass to dart-sass, though support is largely identical, you may notice changes or warnings upon compilation. You may either address these one-by-one, or you can manually switch back to node-sass, like so:

npm install node-sass

mix.sass('resources/sass/app.sass', 'public/css', {
    implementation: require('node-sass')
});

fastSass() and standaloneSass() Removed

mix.fastSass() and mix.standaloneSass() (aliases) have been removed entirely. In an effort to improve performance for those who only need to compile CSS, this command provided Sass compilation that was separate from the core webpack build. However, it seems to be more confusing than helpful to newcomers. Migrate by switching from mix.fastSass() to mix.sass(). 3e478043f7d6cfc73442b2971727d8595b6a559f

Before

mix.fastSass('resources/sass/app.scss', 'public/css');

After

mix.sass('resources/sass/app.scss', 'public/css');

Deprecated .mix Property Removed

The deprecated mix property has now been removed. If you have require('laravel-mix').mix in your webpack.mix.js file, change it to require('laravel-mix'). 7dc010451870c0b23d8e22fe5d0fa67714d7df5f

Before

let mix = require('laravel-mix').mix;

After

let mix = require('laravel-mix');

Switching From Uglify to Terser

Due to the mandatory switch from Uglify to Terser, if your project was overriding our default config with Config.uglify = {}, you'll need to switch to Config.terser = {}. The options API is largely the same.

Before

// webpack.mix.js

mix.options({
    uglify: {
        uglifyOptions: {
            warnings: true
        }
    }
});

After

mix.options({
    terser: {
        terserOptions: {
            warnings: true
        }
    }
});

Vue Component Sass Preprocessing

If your project does not include a mix.sass() call (which automatically downloads all necessary dependencies), but does specify lang="sass" in your Vue components, you may need to install either node-sass or sass. Because Mix doesn't know which preprocessors you specify in your Vue components, you'll need to manually pull them in. Fix it with npm install node-sass sass-loader or npm install sass sass-loader. Please note that the same is true for Less and Stylus.