rollup.config.mjs

import resolve from "@rollup/plugin-node-resolve";
import typescript from "rollup-plugin-typescript2";
import commonjs from "@rollup/plugin-commonjs";
import json from "@rollup/plugin-json";
import terser from "@rollup/plugin-terser";
import pkg from "./package.json" with { type: "json" };

const external = ["assert"];

const banner = `/*!
 * ${pkg.name} v${pkg.version}
 * github.com/samber/chartjs-plugin-datasource-prometheus
 * (c) ${new Date().getFullYear()} chartjs-plugin-datasource-prometheus Contributors
 * Released under the MIT License
 */`;

export default [
  // browser-friendly UMD build
  {
    input: "src/index.ts",
    output: [
      {
        name: "ChartDatasourcePrometheusPlugin",
        file: pkg.browser,
        format: "umd",
        banner,
        globals: {
          "chart.js": "Chart",
        },
        sourcemap: true,
      },
    ],
    external: ["chart.js"],
    plugins: [
      json(),
      // so Rollup can find `axios`
      resolve({
        browser: true,
      }),
      typescript({
        useTsconfigDeclarationDir: true,
        tsconfigOverride: { compilerOptions: { module: "es2015" } },
      }),
      // so Rollup can convert `axios` to an ES module
      commonjs({
        extensions: [".js", ".ts"],
      }),
      terser({
        output: {
          preamble: banner,
        },
      }),
    ],
  },

  // CommonJS (for Node) and ES module (for bundlers) build.
  // (We could have three entries in the configuration array
  // instead of two, but it's quicker to generate multiple
  // builds from a single configuration where possible, using
  // an array for the `output` option, where we can specify
  // `file` and `format` for each target)
  {
    input: "src/index.ts",
    external: [],
    output: [
      {
        file: pkg.main,
        format: "cjs",
        globals: {
          "chart.js": "Chart",
        },
        sourcemap: true,
      },
      {
        file: pkg.module,
        format: "es",
        globals: {
          "chart.js": "Chart",
        },
        sourcemap: true,
      },
    ],
    external: ["chart.js"],
    plugins: [
      typescript({
        tsconfigOverride: { compilerOptions: { module: "es2015" } },
      }),
    ],
  },
];