fix(runtime): navigator.userAgent in web worker (#20129)

Fixes https://github.com/denoland/deno/issues/20079

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

2 files changed, 24 insertions, 15 deletions

diff --git a/runtime/js/98_global_scope.js b/runtime/js/98_global_scope.js
index 1084f5c24..c916ef819 100644
--- a/runtime/js/98_global_scope.js
+++ b/runtime/js/98_global_scope.js
@@ -225,21 +225,29 @@ ObjectDefineProperties(WorkerNavigator.prototype, {
       webidl.assertBranded(this, WorkerNavigatorPrototype);
       return numCpus;
     },
-    language: {
-      configurable: true,
-      enumerable: true,
-      get() {
-        webidl.assertBranded(this, WorkerNavigatorPrototype);
-        return language;
-      },
+  },
+  userAgent: {
+    configurable: true,
+    enumerable: true,
+    get() {
+      webidl.assertBranded(this, WorkerNavigatorPrototype);
+      return userAgent;
+    },
+  },
+  language: {
+    configurable: true,
+    enumerable: true,
+    get() {
+      webidl.assertBranded(this, WorkerNavigatorPrototype);
+      return language;
     },
-    languages: {
-      configurable: true,
-      enumerable: true,
-      get() {
-        webidl.assertBranded(this, WorkerNavigatorPrototype);
-        return [language];
-      },
+  },
+  languages: {
+    configurable: true,
+    enumerable: true,
+    get() {
+      webidl.assertBranded(this, WorkerNavigatorPrototype);
+      return [language];
     },
   },
 });
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index dc6839646..c8fdabc25 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -567,7 +567,7 @@ function bootstrapWorkerRuntime(
     10: pid,
     11: target,
     12: v8Version,
-    // 13: userAgent,
+    13: userAgent,
     // 14: inspectFlag,
     15: enableTestingFeaturesFlag,
   } = runtimeOptions;
@@ -633,6 +633,7 @@ function bootstrapWorkerRuntime(
   location.setLocationHref(location_);
 
   setNumCpus(cpuCount);
+  setUserAgent(userAgent);
   setLanguage(locale);
 
   globalThis.pollForMessages = pollForMessages;