From b439ab18e829e436542a2b4a965f258d749bfc36 Mon Sep 17 00:00:00 2001
From: Danielku15 <danielku15@coderline.net>
Date: Sun, 20 Feb 2022 16:55:58 +0100
Subject: [PATCH] Improve WebPack Support

---
 src/Environment.ts                         | 44 +++++++++++++++++++---
 src/platform/javascript/BrowserUiFacade.ts |  5 ++-
 2 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/src/Environment.ts b/src/Environment.ts
index 4297599eb..0166bdf10 100644
--- a/src/Environment.ts
+++ b/src/Environment.ts
@@ -188,6 +188,11 @@ export class Environment {
      */
     public static webPlatform: WebPlatform = Environment.detectWebPlatform();
 
+    /**
+     * @target web
+     */
+    public static isWebPackBundled: boolean = Environment.detectWebPack();
+
     /**
      * @target web
      */
@@ -216,13 +221,25 @@ export class Environment {
      * @target web
      */
     public static createAlphaTabWorker(scriptFile: string): Worker {
-        if (Environment.webPlatform === WebPlatform.BrowserModule) {
-            let script: string = `import * as alphaTab from '${scriptFile}'`;
-            let blob: Blob = new Blob([script], { type: 'text/javascript' });
+        if (Environment.isWebPackBundled) {
+            // WebPack currently requires this exact syntax: new Worker(new URL(..., import.meta.url)))
+            // The module `@coderline/alphatab` will be resolved by WebPack to alphaTab consumed as library
+            // this will not work with CDNs because worker start scripts need to have the same origin like
+            // the current browser. 
+
+            // https://github.com/webpack/webpack/discussions/14066
+
+            return new Worker(
+                // @ts-ignore
+                /* webpackChunkName: "alphatab.worker" */ new URL('@coderline/alphatab', import.meta.url)
+            );
+        } else if (Environment.webPlatform === WebPlatform.BrowserModule) {
+            const script: string = `import * as alphaTab from '${scriptFile}'`;
+            const blob: Blob = new Blob([script], { type: 'text/javascript' });
             return new Worker(URL.createObjectURL(blob), { type: 'module' });
         } else {
-            let script: string = `importScripts('${scriptFile}')`;
-            let blob: Blob = new Blob([script]);
+            const script: string = `importScripts('${scriptFile}')`;
+            const blob: Blob = new Blob([script]);
             return new Worker(URL.createObjectURL(blob));
         }
     }
@@ -521,6 +538,21 @@ export class Environment {
         }
     }
 
+    /**
+     * @target web
+     */
+    private static detectWebPack(): boolean {
+        try {
+            // @ts-ignore
+            if (typeof __webpack_require__ !== 'function') {
+                return true;
+            }
+        } catch (e) {
+            // ignore any errors
+        }
+        return false;
+    }
+
     /**
      * @target web
      */
@@ -541,7 +573,7 @@ export class Environment {
         try {
             // @ts-ignore
             const url: any = import.meta.url;
-            if (url && typeof url === 'string') {
+            if (url && typeof url === 'string' && !url.startsWith('file://')) {
                 return WebPlatform.BrowserModule;
             }
         } catch (e) {
diff --git a/src/platform/javascript/BrowserUiFacade.ts b/src/platform/javascript/BrowserUiFacade.ts
index 42b975b3a..92b84fd23 100644
--- a/src/platform/javascript/BrowserUiFacade.ts
+++ b/src/platform/javascript/BrowserUiFacade.ts
@@ -498,7 +498,10 @@ export class BrowserUiFacade implements IUiFacade<unknown> {
 
         let player: AlphaSynthWebWorkerApi | null = null;
         let supportsScriptProcessor: boolean = 'ScriptProcessorNode' in window;
-        let supportsAudioWorklets: boolean = window.isSecureContext && 'AudioWorkletNode' in window;
+
+        // Once https://github.com/webpack/webpack/issues/11543 is decided
+        // we can support audio worklets together with WebPack
+        let supportsAudioWorklets: boolean = window.isSecureContext && 'AudioWorkletNode' in window && !Environment.isWebPackBundled;
 
         if (supportsAudioWorklets) {
             Logger.debug('Player', 'Will use webworkers for synthesizing and web audio api with worklets for playback');