rollup.config.mjs

import copy from "rollup-plugin-copy";
import sass from "rollup-plugin-sass";
import typescript from "@rollup/plugin-typescript";
import terser from "@rollup/plugin-terser";
import commonjs from '@rollup/plugin-commonjs';

import autoprefixer from "autoprefixer";
import fs from "fs";
import path from "path";
import postcss from "postcss";

import pkg from "./package.json" with { type: "json" };

const entries = {
  index: "src/plugins/bootstrap.ts",
  scss: "src/assets/scss",
};

const exits = {
  directory: "dist",
  css: "dist/bootstrap.css",
  esm: `${pkg.module}`,
  cjs: `${pkg.main}`,
};

const commonSassPluginOptions = {
  processor: async (css) => {
    const { css: processedCss } = await postcss([autoprefixer]).process(css, {
      from: undefined,
    });
    return processedCss;
  },
  options: {
    includePaths: ["node_modules"],
  },
};

const typescriptPluginOptions = {
  sourceMap: false,
  // skip type checking of declaration files
  skipLibCheck:true,
  // enabling declaration (.d.ts) emit
  declaration: true,
  //  decouple declaration files from actual transpiled JavaScript files
  declarationDir: "dist/types",
  // define included files
  include: "src/plugins/**",
};

function createDirectoryIfDoesNotExist(filePath) {
  const directoryName = path.dirname(filePath);
  if (fs.existsSync(directoryName)) {
    return true;
  }
  createDirectoryIfDoesNotExist(directoryName);
  fs.mkdirSync(directoryName);
}

function createMinifiedFileName(fileName) {
  const fileNameParts = fileName.split(".");
  const fileExtIndex = fileNameParts.length - 1;
  const minifiedFileName = [
    ...fileNameParts.slice(0, fileExtIndex),
    "min",
    fileNameParts[fileExtIndex],
  ].join(".");
  return minifiedFileName;
}

function writeCssFile(fileName, styles) {
  createDirectoryIfDoesNotExist(exits.css);
  fs.writeFileSync(fileName, styles);
}

export default function () {
  const config = [
    {
      input: entries.index,
      external: ["vue", /oruga\/.*/],
      output: [
        {
          format: "esm",
          file: `${exits.esm}`,
        },
        {
          format: "esm",
          file: `${createMinifiedFileName(exits.esm)}`,
          plugins: [terser()],
        },
        {
          format: "cjs",
          name: "OrugaThemeBootstrap",
          file: `${exits.cjs}`,
        },
        {
          format: "cjs",
          name: "OrugaThemeBootstrap",
          file: `${createMinifiedFileName(exits.cjs)}`,
          plugins: [terser()],
        },
      ],
      plugins: [
        copy({
          targets: [{ src: `${entries.scss}`, dest: `${exits.directory}` }],
        }),
        commonjs(),
        sass({
          ...commonSassPluginOptions,
          output(styles) {
            writeCssFile(`${exits.css}`, styles);
          },
        }),
        sass({
          ...commonSassPluginOptions,
          output(styles) {
            writeCssFile(`${createMinifiedFileName(exits.css)}`, styles);
          },
          ...{
            options: {
              outputStyle: "compressed",
              ...commonSassPluginOptions.options,
            },
          },
        }),
        typescript(typescriptPluginOptions),
      ],
    },
  ];
  return config;
}