3 files changed, 36 insertions, 0 deletions
diff --git a/cli/tests/subdir/worker_globals.ts b/cli/tests/subdir/worker_globals.ts
new file mode 100644
index 000000000..a9e7efd85
--- /dev/null
+++ b/cli/tests/subdir/worker_globals.ts
@@ -0,0 +1,10 @@
+onmessage = function (): void {
+  postMessage(
+    [
+      self instanceof DedicatedWorkerGlobalScope,
+      self instanceof WorkerGlobalScope,
+      self instanceof EventTarget,
+    ].join(", "),
+  );
+  close();
+};
diff --git a/cli/tests/unit/globals_test.ts b/cli/tests/unit/globals_test.ts
index 6c83b1b44..53fafc5b6 100644
--- a/cli/tests/unit/globals_test.ts
+++ b/cli/tests/unit/globals_test.ts
@@ -36,6 +36,14 @@ unitTest(function globalThisEqualsSelf(): void {
   assert(globalThis === self);
 });
 
+unitTest(function globalThisInstanceofWindow(): void {
+  assert(globalThis instanceof Window);
+});
+
+unitTest(function globalThisInstanceofEventTarget(): void {
+  assert(globalThis instanceof EventTarget);
+});
+
 unitTest(function DenoNamespaceExists(): void {
   assert(Deno != null);
 });
diff --git a/cli/tests/workers_test.ts b/cli/tests/workers_test.ts
index 395b1da24..06349efa0 100644
--- a/cli/tests/workers_test.ts
+++ b/cli/tests/workers_test.ts
@@ -106,6 +106,24 @@ Deno.test({
 });
 
 Deno.test({
+  name: "worker globals",
+  fn: async function (): Promise<void> {
+    const promise = createResolvable();
+    const w = new Worker(
+      new URL("subdir/worker_globals.ts", import.meta.url).href,
+      { type: "module" },
+    );
+    w.onmessage = (e): void => {
+      assertEquals(e.data, "true, true, true");
+      promise.resolve();
+    };
+    w.postMessage("Hello, world!");
+    await promise;
+    w.terminate();
+  },
+});
+
+Deno.test({
   name: "worker fetch API",
   fn: async function (): Promise<void> {
     const promise = createResolvable();