From 01ab2f279488689bf26db8a0fda2e112f1d3348b Mon Sep 17 00:00:00 2001
From: Shantur Rathore <i@shantur.com>
Date: Mon, 9 Feb 2026 23:56:33 +0000
Subject: [PATCH] fix(ui): boot Monaco diff workers via workerMain

---
 packages/ui/src/lib/monaco/setup.ts           | 21 ++++++++++++-------
 .../ui/src/renderer/public/monaco.worker.js   |  7 +++++++
 2 files changed, 21 insertions(+), 7 deletions(-)
 create mode 100644 packages/ui/src/renderer/public/monaco.worker.js

diff --git a/packages/ui/src/lib/monaco/setup.ts b/packages/ui/src/lib/monaco/setup.ts
index 6411dfba..f28fb2ee 100644
--- a/packages/ui/src/lib/monaco/setup.ts
+++ b/packages/ui/src/lib/monaco/setup.ts
@@ -53,15 +53,22 @@ function ensureLoaderScript(): Promise<void> {
 
 function configureWorkers() {
   const globalAny = globalThis as any
-  if (globalAny.MonacoEnvironment?.getWorkerUrl) return
+  const prevEnv = globalAny.MonacoEnvironment ?? {}
+
+  // Monaco's AMD build no longer ships `editor.worker.js` (and language workers are
+  // `jsonWorker.js`, `cssWorker.js`, etc). The robust approach is to always boot
+  // `vs/base/worker/workerMain.js` and let it `require(...)` the requested module.
+  //
+  // Important: `workerMain.js` expects `MonacoEnvironment.baseUrl` to be the
+  // directory containing the `vs/` folder (so `/monaco/`, not `/monaco/vs`).
+  // Use a static worker bootstrap script rather than a `data:` URL.
+  // This avoids CSP issues and makes worker requests visible in DevTools.
+  const workerUrl = "/monaco.worker.js"
 
   globalAny.MonacoEnvironment = {
-    getWorkerUrl(_moduleId: string, label: string) {
-      if (label === "json") return `${LOCAL_VS_ROOT}/language/json/json.worker.js`
-      if (label === "css" || label === "scss" || label === "less") return `${LOCAL_VS_ROOT}/language/css/css.worker.js`
-      if (label === "html" || label === "handlebars" || label === "razor") return `${LOCAL_VS_ROOT}/language/html/html.worker.js`
-      if (label === "typescript" || label === "javascript") return `${LOCAL_VS_ROOT}/language/typescript/ts.worker.js`
-      return `${LOCAL_VS_ROOT}/editor/editor.worker.js`
+    ...prevEnv,
+    getWorkerUrl(_moduleId: string, _label: string) {
+      return workerUrl
     },
   }
 }
diff --git a/packages/ui/src/renderer/public/monaco.worker.js b/packages/ui/src/renderer/public/monaco.worker.js
new file mode 100644
index 00000000..275a7f99
--- /dev/null
+++ b/packages/ui/src/renderer/public/monaco.worker.js
@@ -0,0 +1,7 @@
+// Monaco web worker bootstrap.
+//
+// `workerMain.js` expects `MonacoEnvironment.baseUrl` to be the directory that
+// contains the `vs/` folder (so `/monaco/`, not `/monaco/vs`).
+self.MonacoEnvironment = { baseUrl: "/monaco/" }
+
+importScripts("/monaco/vs/base/worker/workerMain.js")