rollup.config.js

import babel from "rollup-plugin-babel";
import commonjs from "rollup-plugin-commonjs";
import nodeResolve from "rollup-plugin-node-resolve";
import replace from "rollup-plugin-replace";
import { sizeSnapshot } from "rollup-plugin-size-snapshot";
import sourcemaps from "rollup-plugin-sourcemaps";
import { terser } from "rollup-plugin-terser";
import pkg from "./package.json";

const CJS_DEV = "CJS_DEV";
const CJS_PROD = "CJS_PROD";
const ES = "ES";
const UMD_DEV = "UMD_DEV";
const UMD_PROD = "UMD_PROD";

const input = "./compiled/index.js";

const getGlobals = bundleType => {
  const baseGlobals = {
    "react-dom": "ReactDOM",
    react: "React"
  };

  switch (bundleType) {
    case UMD_DEV:
      return { ...baseGlobals, "prop-types": "PropTypes" };
    case UMD_PROD:
      return baseGlobals;
    default:
      return {};
  }
};

const getExternal = bundleType => {
  const peerDependencies = Object.keys(pkg.peerDependencies);
  const dependencies = Object.keys(pkg.dependencies);

  // Hat-tip: https://github.com/rollup/rollup-plugin-babel/issues/148#issuecomment-399696316.
  const makeExternalPredicate = externals => {
    if (externals.length === 0) {
      return () => false;
    }
    const pattern = new RegExp(`^(${externals.join("|")})($|/)`);
    return id => pattern.test(id);
  };

  switch (bundleType) {
    case CJS_DEV:
    case CJS_PROD:
    case ES:
      return makeExternalPredicate([...peerDependencies, ...dependencies]);
    case UMD_DEV:
      return makeExternalPredicate([...peerDependencies, "prop-types"]);
    default:
      return makeExternalPredicate(peerDependencies);
  }
};

const isProduction = bundleType =>
  bundleType === CJS_PROD || bundleType === UMD_PROD;

const getBabelConfig = bundleType => {
  const options = {
    babelrc: false,
    exclude: "node_modules/**",
    presets: [["@babel/env", { loose: true, modules: false }], "@babel/react"],
    plugins: ["@babel/transform-runtime"],
    runtimeHelpers: true
  };

  switch (bundleType) {
    case ES:
      return {
        ...options,
        plugins: [
          ...options.plugins,
          ["transform-react-remove-prop-types", { mode: "wrap" }]
        ]
      };
    case UMD_PROD:
    case CJS_PROD:
      return {
        ...options,
        plugins: [
          ...options.plugins,
          ["transform-react-remove-prop-types", { removeImport: true }]
        ]
      };
    default:
      return options;
  }
};

const getPlugins = bundleType => [
  nodeResolve(),
  commonjs({
    include: "node_modules/**",
    namedExports: {
      "node_modules/prop-types/index.js": [
        "any",
        "array",
        "arrayOf",
        "bool",
        "element",
        "exact",
        "func",
        "instanceOf",
        "node",
        "number",
        "object",
        "objectOf",
        "oneOf",
        "oneOfType",
        "shape",
        "string",
        "symbol"
      ]
    }
  }),
  babel(getBabelConfig(bundleType)),
  replace({
    "process.env.NODE_ENV": JSON.stringify(
      isProduction(bundleType) ? "production" : "development"
    )
  }),
  sourcemaps(),
  sizeSnapshot(),
  isProduction(bundleType) &&
    terser({
      sourcemap: true,
      output: { comments: false },
      compress: {
        keep_infinity: true, // eslint-disable-line @typescript-eslint/camelcase
        pure_getters: true // eslint-disable-line @typescript-eslint/camelcase
      },
      warnings: true,
      ecma: 5,
      toplevel: false
    })
];

const getCjsConfig = bundleType => ({
  input,
  external: getExternal(bundleType),
  output: {
    file: `dist/react-fiber-traverse.cjs.${
      isProduction(bundleType) ? "production" : "development"
    }.js`,
    format: "cjs",
    sourcemap: true
  },
  plugins: getPlugins(bundleType)
});

const getEsConfig = () => ({
  input,
  external: getExternal(ES),
  output: {
    file: pkg.module,
    format: "es",
    sourcemap: true
  },
  plugins: getPlugins(ES)
});

const getUmdConfig = bundleType => ({
  input,
  external: getExternal(bundleType),
  output: {
    file: `dist/react-fiber-traverse.umd.${
      isProduction(bundleType) ? "production" : "development"
    }.js`,
    format: "umd",
    globals: getGlobals(bundleType),
    name: "reactFiberTraverse",
    sourcemap: true
  },
  plugins: getPlugins(bundleType)
});

export default [
  getCjsConfig(CJS_DEV),
  getCjsConfig(CJS_PROD),
  getEsConfig(),
  getUmdConfig(UMD_DEV),
  getUmdConfig(UMD_PROD)
];