Global plugins not mapped on scene when render type is Phaser.HEADLESS

Version

• Phaser Version: 3.88-3.90
• Operating system: Windows/Linux (Not specific to any)
• Browser: Tested in Firefox/Chrome

Description

As of https://github.com/phaserjs/phaser/commit/8736f0e844c8f924bf129d9364468c2cfa8c250d, plugin keys are not correctly populated on scenes. e.g. a global plugin with a mapping of "test" is not available as scene.test

Example Test Code

This repros with the "global scene plugin" example with no changes other than swapping type to HEADLESS:

class TestPlugin extends Phaser.Plugins.BasePlugin {

    constructor (pluginManager)
    {
        super(pluginManager);
    }

    wibble ()
    {
        console.log('hello');
    }

}

var config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.HEADLESS,
    parent: 'game-container',
    width: 800,
    height: 600,
    plugins: {
        global: [
            { key: 'TestPlugin', plugin: TestPlugin, start: false, mapping: 'test' }
        ]
    },
    scene: {
        preload: preload,
        create: create
    }
};

var game = new Phaser.Game(config);

function preload ()
{
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
    this.load.image('elephant', 'assets/sprites/elephant.png');
}

function create ()
{
    this.test.wibble(); // Error: this.test is undefined
}

Start by comparing Phaser's global scene plugin example with the supplied HEADLESS configuration and inspect commit 8736f0e844c8f924bf129d9364468c2cfa8c250d. Trace how the global plugin mapping is applied to scenes; done means the mapped plugin is available as scene.test in HEADLESS mode, with the relevant regression covered by a test or reproducible example.