How to use rollup-plugin-scss - 1 common examples

// Compile TypeScript files
      // Allow bundling cjs modules (unlike webpack, rollup doesn't understand cjs)
      commonjs(),
      // Allow node_modules resolution, so you can use 'external' to control
      // which external modules to include in the bundle
      // https://github.com/rollup/rollup-plugin-node-resolve#usage
      resolve(),
      babel({
        babelrc: true,
        exclude: 'node_modules/**',
        compact: false
      }),

      // Resolve source maps to the original source
      sourceMaps(),
      scss({
        output: styles => {
          if (styles && styles.length) {
            const cssOutput = css || output[0].file.replace(/\.(umd|es|iife).js/, '.css');
            mkdirp(cssOutput.replace(/[^\/]*$/, ''));
            fs.writeFileSync(cssOutput, styles);
          }
        }
      }),
      ...plugins
    ]
  };
}