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, 31 insertions, 0 deletions

diff --git a/cli/tests/testdata/workers/test.ts b/cli/tests/testdata/workers/test.ts
index 506bb4c31..90cc6a649 100644
--- a/cli/tests/testdata/workers/test.ts
+++ b/cli/tests/testdata/workers/test.ts
@@ -120,6 +120,26 @@ Deno.test({
 });
 
 Deno.test({
+  name: "worker navigator",
+  fn: async function () {
+    const workerOptions: WorkerOptions = { type: "module" };
+    const w = new Worker(
+      import.meta.resolve("./worker_navigator.ts"),
+      workerOptions,
+    );
+
+    const promise = deferred();
+    w.onmessage = (e) => {
+      promise.resolve(e.data);
+    };
+
+    w.postMessage("Hello, world!");
+    assertEquals(await promise, "string, object, string, number");
+    w.terminate();
+  },
+});
+
+Deno.test({
   name: "worker fetch API",
   fn: async function () {
     const fetchingWorker = new Worker(
diff --git a/cli/tests/testdata/workers/worker_navigator.ts b/cli/tests/testdata/workers/worker_navigator.ts
new file mode 100644
index 000000000..bd364a8f9
--- /dev/null
+++ b/cli/tests/testdata/workers/worker_navigator.ts
@@ -0,0 +1,11 @@
+onmessage = function () {
+  postMessage(
+    [
+      typeof navigator.language,
+      typeof navigator.languages,
+      typeof navigator.userAgent,
+      typeof navigator.hardwareConcurrency,
+    ].join(", "),
+  );
+  close();
+};