samme/base.js

## base.js
export class BaseScene extends Phaser.Scene
{
    constructor(config)
    {
        super(config);
    }

    init()
    {
        this.user = this.registry.get('user');
    }
}

## boot.js
export class Boot extends Phaser.Scene
{
    constructor()
    {
        super({ key: 'boot' });
    }

    preload() {}

    create()
    {
        this.scene.start('preloader');
    }
}

## home.js
import { BaseScene } from './base.js';

export class Home extends BaseScene
{
    constructor()
    {
        super({
            key: 'home'
        });
    }

    init (data)
    {
        super.init();
    }

    create ()
    {
        this.add.text(20, 15, 'BaseScene Test', { fontFamily: 'Courier', fontSize: 30, color: 'white', align: 'left' }).setOrigin(0);
        this.add.text(20, 65, this.user.username, { fontFamily: 'Courier', fontSize: 30, color: 'white', align: 'left' }).setOrigin(0);
    }

    update () {}
}

## index.html
<html>

<head>
    <title>BaseScene Test</title>
</head>

<body style="margin:0px">

    <script src="https://cdn.jsdelivr.net/npm/phaser@3.22.0/dist/phaser.js"></script>
    <script type="module" src="index.js"></script>

</body>

</html>

## index.js
import { Boot } from './boot';
import { Preloader } from './preloader';
import { Home } from './home';

const config = {
    scale: {
        mode: Phaser.Scale.FIT,
        parent: 'phaser-example',
        autoCenter: Phaser.Scale.CENTER_BOTH,
        width: 1136,
        height: 640
    },
    scene: [
        Boot,
        Preloader,
        Home
    ],
    callbacks: {
        postBoot: function (game) {
            game.scene.dump();
        }
    }
};

const game = new Phaser.Game(config);

## preloader.js
export class Preloader extends Phaser.Scene
{
    constructor()
    {
        super({
            key: 'preloader'
        });
    }

    preload()
    {
        this.load.json('userData', 'user.json');
    }

    create()
    {
        var user = this.cache.json.get('userData');
        this.registry.set('user', user);

        this.scene.start('home');
    }
}

## user.json
{"id":1,"username":"batman"}
	export class BaseScene extends Phaser.Scene
	{
	constructor(config)
	{
	super(config);
	}

	init()
	{
	this.user = this.registry.get('user');
	}
	}
	export class Boot extends Phaser.Scene
	{
	constructor()
	{
	super({ key: 'boot' });
	}

	preload() {}

	create()
	{
	this.scene.start('preloader');
	}
	}
	import { BaseScene } from './base.js';

	export class Home extends BaseScene
	{
	constructor()
	{
	super({
	key: 'home'
	});
	}

	init (data)
	{
	super.init();
	}

	create ()
	{
	this.add.text(20, 15, 'BaseScene Test', { fontFamily: 'Courier', fontSize: 30, color: 'white', align: 'left' }).setOrigin(0);
	this.add.text(20, 65, this.user.username, { fontFamily: 'Courier', fontSize: 30, color: 'white', align: 'left' }).setOrigin(0);
	}

	update () {}
	}
	<html>

	<head>
	<title>BaseScene Test</title>
	</head>

	<body style="margin:0px">

	<script src="https://cdn.jsdelivr.net/npm/phaser@3.22.0/dist/phaser.js"></script>
	<script type="module" src="index.js"></script>

	</body>

	</html>
	import { Boot } from './boot';
	import { Preloader } from './preloader';
	import { Home } from './home';

	const config = {
	scale: {
	mode: Phaser.Scale.FIT,
	parent: 'phaser-example',
	autoCenter: Phaser.Scale.CENTER_BOTH,
	width: 1136,
	height: 640
	},
	scene: [
	Boot,
	Preloader,
	Home
	],
	callbacks: {
	postBoot: function (game) {
	game.scene.dump();
	}
	}
	};

	const game = new Phaser.Game(config);
	export class Preloader extends Phaser.Scene
	{
	constructor()
	{
	super({
	key: 'preloader'
	});
	}

	preload()
	{
	this.load.json('userData', 'user.json');
	}

	create()
	{
	var user = this.cache.json.get('userData');
	this.registry.set('user', user);

	this.scene.start('home');
	}
	}