rollup.config.js

import * as meta from "./package.json" with { type: "json" };

// ------ JavaScript
import { babel } from "@rollup/plugin-babel";
import commonjs from "@rollup/plugin-commonjs";
import eslint from "@rollup/plugin-eslint";
import terser from "@rollup/plugin-terser";

// ------ CSS
import sass from "rollup-plugin-sass";

// ------ global
import resolve from "@rollup/plugin-node-resolve";

const plugins = [
  eslint({
    include: ["src/**/*.js"],
  }),
  babel({
    babelHelpers: "bundled",
    include: "src/**",
    presets: ["@babel/preset-env"],
  }),
  // terser(),
  sass({ output: true }),
  resolve(),
  commonjs(),
];

const config = {
  input: "src/index.js",
  external: Object.keys(meta.default.dependencies || {}).filter((key) =>
    /^d3-/.test(key),
  ),
  output: {
    file: `dist/${meta.default.name}.js`,
    name: "d3",
    format: "umd",
    indent: false,
    extend: true,
    banner: `// ${meta.default.homepage} v${meta.default.version} Copyright ${new Date().getFullYear()} ${meta.default.author.name}`,
    globals: Object.assign(
      {},
      ...Object.keys(meta.default.dependencies || {})
        .filter((key) => /^d3-/.test(key))
        .map((key) => ({ [key]: "d3" })),
    ),
  },
  watch: {
    chokidar: false,
    include: ["src/**", "styles/**", "example/*.html", "example/data/*.*"],
  },
  plugins,
};

export default [
  config,
  {
    ...config,
    output: {
      ...config.output,
      file: `dist/${meta.default.name}.min.js`,
    },
    plugins: [
      ...config.plugins,
      terser({
        output: {
          preamble: config.output.banner,
        },
      }),
    ],
  },
];