rollup.config.js

import { nodeResolve } from '@rollup/plugin-node-resolve';
import { createFilter } from '@rollup/pluginutils';
import terser from '@rollup/plugin-terser';

function string(opts = {}) {
  if (!opts.include) {
    throw Error('include option should be specified');
  }

  const filter = createFilter(opts.include, opts.exclude);

  return {
    name: 'string',

    transform(code, id) {
      if (filter(id)) {
        return {
          code: `export default ${JSON.stringify(code)};`,
          map: { mappings: '' },
        };
      }
    },

    renderChunk(code, chunk, outputOptions = {}) {
      return (
        `/*!
 * Live2D Widget
 * https://github.com/stevenjoezhang/live2d-widget
 */
` + code
      );
    },
  };
}

export default {
  input: 'build/index.js',
  output: {
    name: 'live2d_widget',
    file: 'dist/waifu-tips.js',
    format: 'iife',
  },
  plugins: [
    nodeResolve(),
    string({
      include: '**/*.svg',
    }),
    terser(),
  ],
  context: 'this',
};