Incoporate SASS (SCSS) Webpack with Angular 4 Application

Question

Sorry, this is another webpack/scss/sass question. Looking for answers has me going dizzy, especially still being new to webpack and angular.

I want to use sass/scss files with an Angular 4 application I have created using Visual Studio 2017 ASP.NET Core Angular project template.

Out of the box, it generates the files to get you going. I just want to create a new scss file for the app.component - app.component.scss.

I've done this and tried to best guess how to get something to manipulate the scss files. I'm totally unclear on what is required. I see sass-loader used in most examples on the net, but they have different configurations - which does confuse me.

So I'm sending out a big SOS here. What do I need to do to get scss files working in my scenario?

Here is what I have:

package.json

This is the initial file generated from the Visual Studio template:

{
  "name": "AngularShell_Web",
  "private": true,
  "version": "0.0.0",
  "scripts": {
    "test": "karma start ClientApp/test/karma.conf.js"
  },
  "dependencies": {
    "@angular/animations": "4.2.5",
    "@angular/common": "4.2.5",
    "@angular/compiler": "4.2.5",
    "@angular/compiler-cli": "4.2.5",
    "@angular/core": "4.2.5",
    "@angular/forms": "4.2.5",
    "@angular/http": "4.2.5",
    "@angular/platform-browser": "4.2.5",
    "@angular/platform-browser-dynamic": "4.2.5",
    "@angular/platform-server": "4.2.5",
    "@angular/router": "4.2.5",
    "@ngtools/webpack": "1.5.0",
    "@types/webpack-env": "1.13.0",
    "angular2-template-loader": "0.6.2",
    "aspnet-prerendering": "^3.0.1",
    "aspnet-webpack": "^2.0.1",
    "awesome-typescript-loader": "3.2.1",
    "bootstrap": "3.3.7",
    "css": "2.2.1",
    "css-loader": "0.28.4",
    "es6-shim": "0.35.3",
    "event-source-polyfill": "0.0.9",
    "expose-loader": "0.7.3",
    "extract-text-webpack-plugin": "2.1.2",
    "file-loader": "0.11.2",
    "html-loader": "0.4.5",
    "isomorphic-fetch": "2.2.1",
    "jquery": "3.2.1",
    "json-loader": "0.5.4",
    "preboot": "4.5.2",
    "raw-loader": "0.5.1",
    "reflect-metadata": "0.1.10",
    "rxjs": "5.4.2",
    "style-loader": "0.18.2",
    "to-string-loader": "1.1.5",
    "typescript": "2.4.1",
    "url-loader": "0.5.9",
    "webpack": "2.5.1",
    "webpack-hot-middleware": "2.18.2",
    "webpack-merge": "4.1.0",
    "zone.js": "0.8.12"
  },
  "devDependencies": {
    "@types/chai": "4.0.1",
    "@types/jasmine": "2.5.53",
    "chai": "4.0.2",
    "jasmine-core": "2.6.4",
    "karma": "1.7.0",
    "karma-chai": "0.1.0",
    "karma-chrome-launcher": "2.2.0",
    "karma-cli": "1.0.1",
    "karma-jasmine": "1.1.0",
    "karma-webpack": "2.0.3"
  }
}

I have installed the following node modules using npm install --save and npm install --save-dev:

Module       | Version
---------    | -------
node-sass    | ^4.5.3 
sass-loader  | ^6.0.6
style-loader | https://registry.npmjs.org/style-loader/-/style-loader-0.18.2.tgz

NOTE: Not too sure why style-loader version is like that.

app\components\app.component.html

<div class='container-fluid'>
    <div class='row'>
        <div class='col-sm-3'>
            <nav-menu></nav-menu>
        </div>
        <div class='col-sm-9 body-content'>
            <router-outlet></router-outlet>
        </div>
    </div>
</div>

app\components\app.component.css

@media (max-width: 767px) {
    /* On small screens, the nav menu spans the full width of the screen. Leave a space for it. */
    .body-content {
        padding-top: 50px;
    }
}

app.component.ts

import { Component } from '@angular/core';

@Component({
    selector: 'app',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
}

webpack.config.js

This has my attempted changes to try and load the sass:

const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');
const AotPlugin = require('@ngtools/webpack').AotPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;

module.exports = (env) => {
    // Configuration in common to both client-side and server-side bundles
    const isDevBuild = !(env && env.prod);
    const sharedConfig = {
        stats: { modules: false },
        context: __dirname,
        resolve: { extensions: [ '.js', '.ts' ] },
        output: {
            filename: '[name].js',
            publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
        },
        module: {
            rules: [
                { test: /\.ts$/, include: /ClientApp/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '@ngtools/webpack' },
                { test: /\.html$/, use: 'html-loader?minimize=false' },
                { test: /\.css$/, use: [ 'to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
                { test: /\.scss$/, use: [ 'to-string-loader', isDevBuild ? 'sass-loader' : 'sass-loader?minimize' ] },
                { test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
            ]
        },
        plugins: [new CheckerPlugin()]
    };

    // Configuration for client-side bundle suitable for running in browsers
    const clientBundleOutputDir = './wwwroot/dist';
    const clientBundleConfig = merge(sharedConfig, {
        entry: { 'main-client': './ClientApp/boot.browser.ts' },
        output: { path: path.join(__dirname, clientBundleOutputDir) },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./wwwroot/dist/vendor-manifest.json')
            })
        ].concat(isDevBuild ? [
            // Plugins that apply in development builds only
            new webpack.SourceMapDevToolPlugin({
                filename: '[file].map', // Remove this line if you prefer inline source maps
                moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
            })
        ] : [
            // Plugins that apply in production builds only
            new webpack.optimize.UglifyJsPlugin(),
            new AotPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.module.browser#AppModule'),
                exclude: ['./**/*.server.ts']
            })
        ])
    });

    // Configuration for server-side (prerendering) bundle suitable for running in Node
    const serverBundleConfig = merge(sharedConfig, {
        resolve: { mainFields: ['main'] },
        entry: { 'main-server': './ClientApp/boot.server.ts' },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./ClientApp/dist/vendor-manifest.json'),
                sourceType: 'commonjs2',
                name: './vendor'
            })
        ].concat(isDevBuild ? [] : [
            // Plugins that apply in production builds only
            new AotPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.module.server#AppModule'),
                exclude: ['./**/*.browser.ts']
            })
        ]),
        output: {
            libraryTarget: 'commonjs',
            path: path.join(__dirname, './ClientApp/dist')
        },
        target: 'node',
        devtool: 'inline-source-map'
    });

    return [clientBundleConfig, serverBundleConfig];
};

webpack.config.vendor.js

const path = require('path');
const webpack = require('webpack');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const merge = require('webpack-merge');
const treeShakableModules = [
    '@angular/animations',
    '@angular/common',
    '@angular/compiler',
    '@angular/core',
    '@angular/forms',
    '@angular/http',
    '@angular/platform-browser',
    '@angular/platform-browser-dynamic',
    '@angular/router',
    'zone.js',
];
const nonTreeShakableModules = [
    'bootstrap',
    'bootstrap/dist/css/bootstrap.css',
    'es6-promise',
    'es6-shim',
    'event-source-polyfill',
    'jquery',
];
const allModules = treeShakableModules.concat(nonTreeShakableModules);

module.exports = (env) => {
    const extractCSS = new ExtractTextPlugin('vendor.css');
    const isDevBuild = !(env && env.prod);
    const sharedConfig = {
        stats: { modules: false },
        resolve: { extensions: ['.js'] },
        module: {
            rules: [
                { test: /\.(png|woff|woff2|eot|ttf|svg)(\?|$)/, use: 'url-loader?limit=100000' }
            ]
        },
        output: {
            publicPath: 'dist/',
            filename: '[name].js',
            library: '[name]_[hash]'
        },
        plugins: [
            new webpack.ProvidePlugin({ $: 'jquery', jQuery: 'jquery' }), // Maps these identifiers to the jQuery package (because Bootstrap expects it to be a global variable)
            new webpack.ContextReplacementPlugin(/\@angular\b.*\b(bundles|linker)/, path.join(__dirname, './ClientApp')), // Workaround for https://github.com/angular/angular/issues/11580
            new webpack.ContextReplacementPlugin(/angular(\\|\/)core(\\|\/)@angular/, path.join(__dirname, './ClientApp')), // Workaround for https://github.com/angular/angular/issues/14898
            new webpack.IgnorePlugin(/^vertx$/) // Workaround for https://github.com/stefanpenner/es6-promise/issues/100
        ]
    };

    const clientBundleConfig = merge(sharedConfig, {
        entry: {
            // To keep development builds fast, include all vendor dependencies in the vendor bundle.
            // But for production builds, leave the tree-shakable ones out so the AOT compiler can produce a smaller bundle.
            vendor: isDevBuild ? allModules : nonTreeShakableModules
        },
        output: { path: path.join(__dirname, 'wwwroot', 'dist') },
        module: {
            rules: [
                { test: /\.css(\?|$)/, use: extractCSS.extract({ use: isDevBuild ? 'css-loader' : 'css-loader?minimize' }) },
                { test: /\.scss(\?|$)/, use: extractCSS.extract({ use: isDevBuild ? 'sass-loader' : 'sass-loader?minimize' }) }
            ]
        },
        plugins: [
            extractCSS,
            new webpack.DllPlugin({
                path: path.join(__dirname, 'wwwroot', 'dist', '[name]-manifest.json'),
                name: '[name]_[hash]'
            })
        ].concat(isDevBuild ? [] : [
            new webpack.optimize.UglifyJsPlugin()
        ])
    });

    const serverBundleConfig = merge(sharedConfig, {
        target: 'node',
        resolve: { mainFields: ['main'] },
        entry: { vendor: allModules.concat(['aspnet-prerendering']) },
        output: {
            path: path.join(__dirname, 'ClientApp', 'dist'),
            libraryTarget: 'commonjs2',
        },
        module: {
            rules: [
                    { test: /\.css(\?|$)/, use: ['to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize'] },
                    { test: /\.scss(\?|$)/, use: ['to-string-loader', isDevBuild ? 'sass-loader' : 'sass-loader?minimize'] }
            ]
        },
        plugins: [
            new webpack.DllPlugin({
                path: path.join(__dirname, 'ClientApp', 'dist', '[name]-manifest.json'),
                name: '[name]_[hash]'
            })
        ]
    });

    return [clientBundleConfig, serverBundleConfig];
}

Updated app.component.ts

import { Component } from '@angular/core';

@Component({
selector: 'app',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css', './app.component.scss']
})
export class AppComponent {
}

Updated app.component.html

This now has a span with class test which is defined in sass:

<div class='container-fluid'>
    <div class='row'>
        <div class='col-sm-3'>
            <nav-menu></nav-menu>
        </div>
        <div class='col-sm-9 body-content'>
            <span class="test">Test</span>
            <router-outlet></router-outlet>
        </div>
    </div>
</div>

Finally, the new sass file app.component.scss

I want to use this in my app.

.test {
    color: red;
}

When I run the application (Visual Studio F5), I get the following error in Chrome:

NodeInvocationException: Prerendering failed because of error: Error: Module parse failed:       
G:\vs\AngularLearn\shell\src\AngularShell.Web\node_modules\sass-loader\lib\loader.js!     
G:\vs\AngularLearn\shell\src\AngularShell.Web\ClientApp\app\components\app\app.component.scss Unexpected token (1:0)
You may need an appropriate loader to handle this file type.
| .test {
| color: red; }
| 

This question might be related, but doesn't give me the information what I need - I'm still confused.

Answer 1

It looks like your prerendering is failing, which might make sense as you have the rules for scss in the clientBundleConfig but not the serverBundleConfig. Try adding the same rules to serverBundleConfig or in shared like I have:

const sharedConfig = {
    stats: { modules: false },
    context: __dirname,
    resolve: { extensions: [ '.js', '.ts' ] },
    output: {
        filename: '[name].js',
        publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
    },
    module: {
        rules: [
            { test: /\.ts$/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader'] : '@ngtools/webpack' },
            { test: /\.html$/, use: 'html-loader?minimize=false' },
            { test: /\.css$/, use: [ 'to-string-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
            { test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' },
            {
                test: /\.scss$/,
                // exclude: /node_modules/,
                use: extractCSS.extract({
                    use: ['css-loader', 'sass-loader']
                })
            },
        ]
    },
    plugins: [new CheckerPlugin(), extractCSS]
};

Answer 2

sass should be compiled automatically in angular with webpack, just place a .scss in you components and i should get compiled