rollup.base-config.js

import * as path from "path";
import filesize from "rollup-plugin-filesize";
import resolve from "rollup-plugin-node-resolve";
import { terser } from "rollup-plugin-terser";
import replace from "rollup-plugin-replace";

const devPlugins = () => [resolve(), filesize()];

// For umd builds, set process.env.NODE_ENV to "development" since 'process' is not available in the browser
const devPluginsUmd = () => [
  resolve(),
  replace({ "process.env.NODE_ENV": JSON.stringify("development") }),
  filesize(),
];

const prodPlugins = () => [
  resolve(),
  replace({ "process.env.NODE_ENV": JSON.stringify("production") }),
  terser(),
  filesize(),
];

export const baseConfig = ({
  input,
  globals,
  umdName,
  external,
  outFile,
  format,
  mode,
}) => ({
  input,
  output: {
    file: path.join("./dist", outFile),
    format: format,
    globals,
    name: format === "umd" ? umdName : undefined,
  },
  external,
  plugins:
    mode === "production"
      ? prodPlugins()
      : format === "umd"
      ? devPluginsUmd()
      : devPlugins(),
});