rollup.config.dev.js

import babel from "rollup-plugin-babel";
import commonjs from "rollup-plugin-commonjs";
import { eslint } from "rollup-plugin-eslint";
import livereload from "rollup-plugin-livereload";
import image from "rollup-plugin-img";
import omit from "object.omit";
import path from "path";
import postcss from "rollup-plugin-postcss";
import replace from "rollup-plugin-replace";
import resolve from "rollup-plugin-node-resolve";
import serve from "rollup-plugin-serve";

var pkg = require("./package.json");
var cache;

const plugins = [
  image({
    limit: 10000
  }),
  postcss({
    extensions: [".css", ".scss"],
    extract: "dev/script/style.css",
    minimize: true,
    modules: {
      // customize the name of the css classes that are created
      generateScopedName: "[local]___[hash:base64:5]"
    },
    sourceMap: "inline" // true, "inline" or false
  }),
  resolve({
    browser: true,
    customResolveOptions: {
      moduleDirectory: "node_modules"
    },
    extensions: [".js", ".jsx"],
    jsnext: true,
    main: true,
    module: true
  }),
  replace({ "process.env.NODE_ENV": JSON.stringify("development") }),
  commonjs({
    include: ["node_modules/**"],
    exclude: ["node_modules/process-es6/**"],
    namedExports: {
      "node_modules/react/index.js": [
        "Children",
        "Component",
        "Fragment",
        "PureComponent",
        "createElement",
        "lazy",
        "useState",
        "Suspense"
      ],
      "node_modules/react-dom/index.js": ["render"],
      "node_modules/react-is/index.js": ["isValidElementType"]
    }
  }),
  eslint({
    exclude: ["**/*.scss", "**/*.css", "node_modules/**"]
  }),
  babel({
    exclude: ["node_modules/**", "__tests__/**"]
  }),
];

if (process.env.npm_lifecycle_event === 'start') {
  plugins.push(
    serve({
      open: true,
      verbose: true,
      contentBase: ["dev"],
      historyApiFallback: false,
      host: "localhost",
      port: 10001
    }),
    livereload()
  )
}

export default {
  input: "src/app.js",
  cache: cache,
  output: {
    file: "dev/script/index.umd.js",
    format: "umd",
    name: "pureReactCarousel",
    sourcemap: true,
    sourcemapFile: path.resolve("dev/main.umd.js")
  },
  // exclude peerDependencies from our bundle, except for react, react-dom, prop-types when dev'ing
  external: Object.keys(omit(pkg.peerDependencies, ["react", "react-dom"])),
  plugins
};