From 2cf210371c432a4400ad4a8eff069f8309148f85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Mangeonjean?= <loic@coderpad.io>
Date: Tue, 30 Jan 2024 14:44:14 +0100
Subject: [PATCH] feat: allow crossorigin workers

---
 src/features/viewPanels.ts     |  1 +
 src/tools/crossOriginWorker.ts | 15 +++++++++++++++
 src/worker.ts                  |  1 +
 3 files changed, 17 insertions(+)
 create mode 100644 src/tools/crossOriginWorker.ts

diff --git a/src/features/viewPanels.ts b/src/features/viewPanels.ts
index 206195a..34187d7 100644
--- a/src/features/viewPanels.ts
+++ b/src/features/viewPanels.ts
@@ -2,6 +2,7 @@ import getMarkersServiceOverride from '@codingame/monaco-vscode-markers-service-
 import getOutputServiceOverride from '@codingame/monaco-vscode-output-service-override'
 import { registerServices } from '../services'
 import { registerWorkerLoader } from '../worker'
+import { Worker } from '../tools/crossOriginWorker'
 import '@codingame/monaco-vscode-references-view-default-extension'
 
 registerWorkerLoader('outputLinkComputer', () => new Worker(new URL('@codingame/monaco-vscode-output-service-override/worker', import.meta.url)))
diff --git a/src/tools/crossOriginWorker.ts b/src/tools/crossOriginWorker.ts
new file mode 100644
index 0000000..74cef34
--- /dev/null
+++ b/src/tools/crossOriginWorker.ts
@@ -0,0 +1,15 @@
+/**
+ * Cross origin workers don't work
+ * The workaround used by vscode is to start a worker on a blob url containing a short script calling 'importScripts'
+ * importScripts accepts to load the code inside the blob worker
+ */
+class CrossOriginWorker extends Worker {
+  constructor (url: string | URL, options: WorkerOptions = {}) {
+    const fullUrl = new URL(url, window.location.href).href
+    const js = options.type === 'module' ? `import '${fullUrl}';` : `importScripts('${fullUrl}');`
+    const blob = new Blob([js], { type: 'application/javascript' })
+    super(URL.createObjectURL(blob), options)
+  }
+}
+
+export { CrossOriginWorker as Worker }
diff --git a/src/worker.ts b/src/worker.ts
index 5f5bc57..5c0d289 100644
--- a/src/worker.ts
+++ b/src/worker.ts
@@ -1,3 +1,4 @@
+import { Worker } from './tools/crossOriginWorker'
 export type WorkerLoader = () => Worker
 
 const workerLoaders: Partial<Record<string, WorkerLoader>> = {