vue.config.js

const path = require( 'path' );
const CKEditorWebpackPlugin = require( '@ckeditor/ckeditor5-dev-webpack-plugin' );
const { styles } = require( '@ckeditor/ckeditor5-dev-utils' );

module.exports = {
    parallel: false,
    // The source of CKEditor is encapsulated in ES6 modules. By default, the code
    // from the node_modules directory is not transpiled, so you must explicitly tell
    // the CLI tools to transpile JavaScript files in all ckeditor5-* modules.
    transpileDependencies: [
        /ckeditor5-[^/\\]+[/\\]src[/\\].+\.js$/,
    ],

    configureWebpack: {
        entry: 'src/index.js',
        plugins: [
            // CKEditor needs its own plugin to be built using webpack.
            new CKEditorWebpackPlugin( {
                // See https://ckeditor.com/docs/ckeditor5/latest/features/ui-language.html
                language: 'en',
                buildAllTranslationsToSeparateFiles: true
            } )
        ]
    },

    // Vue CLI would normally use its own loader to load .svg and .css files, however:
    //	1. The icons used by CKEditor must be loaded using raw-loader,
    //	2. The CSS used by CKEditor must be transpiled using PostCSS to load properly.
    chainWebpack: config => {
        // (1.) To handle the editor icons, get the default rule for *.svg files first:
        const svgRule = config.module.rule( 'svg' );

        // Then you can either:
        //
        // * clear all loaders for existing 'svg' rule:
        //
        svgRule.uses.clear();
        //
        // * or exclude ckeditor directory from node_modules:
        svgRule.exclude.add( path.join( __dirname, 'node_modules', '@ckeditor' ) );

        config.module
        .rule( 'svg' )
        .test( /ckeditor5-[^/\\]+[/\\]theme[/\\]icons[/\\][^/\\]+\.svg$/ )
        .use( 'file-loader' )
        .loader( 'raw-loader' );

        config.module
        .rule( 'svg' )
        .test( /^.*.svg$/ )
        .use( 'file-loader' )
        .loader( 'raw-loader' );

        // (2.) Transpile the .css files imported by the editor using PostCSS.
        // Make sure only the CSS belonging to ckeditor5-* packages is processed this way.
        config.module
            .rule( 'cke-css' )
            .test( /ckeditor5-[^/\\]+[/\\].+\.css$/ )
            .use( 'postcss-loader' )
            .loader( 'postcss-loader' )
            .tap( () => {
                return styles.getPostCssConfig( {
                    themeImporter: {
                        themePath: require.resolve( '@ckeditor/ckeditor5-theme-lark' ),
                    },
                    minify: true
                } );
            } );
    }
};