I try to use `importmap` with Phaser 4 but I have an error

Phaser 4
1

Hello, guys! I try to use importmap with Phaser 4 but I have this error on Plunker: VM535 +esm:29 Uncaught ReferenceError: Cannot access 'jn' before initialization and null on PlayCode.

Playgrounds:

index.html

<!doctype html>

<html>
<head>
    <title>Example</title>
    <link rel="stylesheet" href="css/style.css">
</head>

<body>
    <canvas id="renderCanvas"></canvas>

    <!-- Since importmap is not yet supported by all browsers, it is
        necessary to add the polyfill es-module-shims.min.js -->
    <script async src="https://unpkg.com/es-module-shims@0.1.7/dist/es-module-shims.min.js"></script>

    <script type="importmap">
        {
            "imports": {
                "phaser": "https://cdn.jsdelivr.net/npm/@phaserjs/phaser@0.2.2/+esm"
            }
        }
    </script>

    <script type="module" src="./js/main.js"></script>
</body>
</html>

js/main.js

import phaser from "phaser";

console.log(phaser);
2

I don’t need Phaser 4 because Phaser 3 supports ESM:

Sandboxes:

index.html

<!doctype html>

<html>
<head>
    <title>Example</title>
    <link rel="stylesheet" href="css/style.css">
</head>

<body>
    <canvas id="renderCanvas"></canvas>

    <!-- Since importmap is not yet supported by all browsers, it is
        necessary to add the polyfill es-module-shims.min.js -->
    <script async src="https://unpkg.com/es-module-shims@0.1.7/dist/es-module-shims.min.js"></script>

    <script type="importmap">
        {
            "imports": {
                "@box2d/core": "https://cdn.jsdelivr.net/npm/@box2d/core@0.10.0/+esm",
                "phaser": "https://cdn.jsdelivr.net/npm/phaser@3.60.0/dist/phaser.esm.js"
            }
        }
    </script>

    <script type="module" src="./js/main.js"></script>
</body>
</html>

js/main.js

import { b2World } from "@box2d/core";
import { AUTO, Scene, Game } from "phaser";

// Box2D
const world = b2World.Create({ x: 0, y: 3 });
console.log(world.GetGravity());

// Phaser
console.log(Game);
3

Scripts to create debug and release bundles with Rollup (you don’t need to install Phaser locally):

  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "dev": "rollup -cwm",
    "del-bundle-map": "del /f /q /s .\\public\\js\\bundle.js.map",
    "bundle": "rollup -cm",
    "minify": "uglifyjs public/js/bundle.js -o public/js/bundle.js",
    "release": "npm run bundle && npm run minify && npm run del-bundle-map"
  },

rollup-config.js

export default {
    input: "./src/main.js",
    output: {
        file: "public/js/bundle.js"
    }
}
4