rollup-app.config.js

import merge from 'deepmerge';
import copy from 'rollup-plugin-copy';
// use createSpaConfig for bundling a Single Page App
import { createSpaConfig } from '@open-wc/building-rollup';

// use createBasicConfig to do regular JS to JS bundling
// import { createBasicConfig } from '@open-wc/building-rollup';

const baseConfig = createSpaConfig({
    // use the outputdir option to modify where files are output
    outputDir: 'dist-app',

    // if you need to support older browsers, such as IE11, set the legacyBuild
    // option to generate an additional build just for this browser
    // legacyBuild: true,

    // development mode creates a non-minified build for debugging or development
    developmentMode: process.env.ROLLUP_WATCH === 'true',

    // set to true to inject the service worker registration into your index.html
    injectServiceWorker: false,

});

export default merge(baseConfig, {
    // if you use createSpaConfig, you can use your index.html as entrypoint,
    // any <script type="module"> inside will be bundled by rollup
    //input: ['./demo-app/index.html'],
    input: './demo-app/index.html',

    // alternatively, you can use your JS as entrypoint for rollup and
    // optionally set a HTML template manually
    // input: './app.js',

    plugins: [
        copy({
          targets: [
            { src: ['./demo-app/applications.json'], dest: 'dist-app' },
          ]
        })
    ]
});