rollup.config.cjs

const peerDepsExternal = require("rollup-plugin-peer-deps-external");
const resolve  = require("@rollup/plugin-node-resolve");
const commonjs  = require("@rollup/plugin-commonjs");
const typescript  = require("rollup-plugin-typescript2");
const postcss  = require("rollup-plugin-postcss");
const copy  = require("rollup-plugin-copy");
const json  = require("@rollup/plugin-json");
const path  = require("path");

const packageJson = require("./package.json");
const outputDir = "dist";

const postcssOptions = () => ({
  extensions: [".scss"],
  extract: false,
  minimize: true,
  use: {
    stylus: undefined,
    less: undefined,
    sass: {
      includePaths: [
        "./node_modules",
        // This is only needed because we're using a local module. :-/
        // Normally, you would not need this line.
        path.resolve(__dirname, "..", "node_modules"),
      ],
    },
  },
});

module.exports = {
  input: "./src/index.ts",
  output: [
    {
      file: packageJson.main,
      format: "cjs",
      sourcemap: true,
    },
    {
      file: packageJson.module,
      format: "esm",
      sourcemap: true,
    },
  ],
  plugins: [
    peerDepsExternal(),
    resolve({ preferBuiltins: true }),
    commonjs(),
    typescript({
      exclude: ["src/stories/**/*.*"],
    }),
    postcss(postcssOptions()),
    json(),
    copy({
      targets: [
        {
          src: "src/styles/GridTheme.scss",
          dest: `${outputDir}`,
        },
      ],
    }),
  ],
};