4 files changed, 44 insertions, 0 deletions
diff --git a/cli/tests/integration/run_tests.rs b/cli/tests/integration/run_tests.rs
index d2997d747..2e2b0400c 100644
--- a/cli/tests/integration/run_tests.rs
+++ b/cli/tests/integration/run_tests.rs
@@ -1155,6 +1155,11 @@ itest!(error_import_map_unable_to_load {
   exit_code: 1,
 });
 
+itest!(worker_event_handler_test {
+  args: "run --quiet --reload --allow-read worker_event_handler_test.js",
+  output: "worker_event_handler_test.js.out",
+});
+
 #[test]
 fn no_validate_asm() {
   let output = util::deno_cmd()
diff --git a/cli/tests/worker_event_handler_test.js b/cli/tests/worker_event_handler_test.js
new file mode 100644
index 000000000..e0ce3d9f8
--- /dev/null
+++ b/cli/tests/worker_event_handler_test.js
@@ -0,0 +1,5 @@
+const w = new Worker(
+  new URL("./workers/worker_event_handlers.js", import.meta.url).href,
+  { type: "module" },
+);
+w.postMessage({});
diff --git a/cli/tests/worker_event_handler_test.js.out b/cli/tests/worker_event_handler_test.js.out
new file mode 100644
index 000000000..5556633b1
--- /dev/null
+++ b/cli/tests/worker_event_handler_test.js.out
@@ -0,0 +1,11 @@
+Target from self.onmessage: [object DedicatedWorkerGlobalScope]
+Target from message event listener: [object DedicatedWorkerGlobalScope]
+Arguments from self.onerror: [
+  "Some error message",
+  "",
+  0,
+  0,
+  Error: Some error message
+    at [WILDCARD]
+]
+Is event canceled?: true
diff --git a/cli/tests/workers/worker_event_handlers.js b/cli/tests/workers/worker_event_handlers.js
new file mode 100644
index 000000000..c8976f79e
--- /dev/null
+++ b/cli/tests/workers/worker_event_handlers.js
@@ -0,0 +1,23 @@
+self.onmessage = (evt) => {
+  console.log("Target from self.onmessage:", String(evt.target));
+};
+
+self.addEventListener("message", (evt) => {
+  console.log("Target from message event listener:", String(evt.target));
+
+  // Throw an error here so the global's error event will fire.
+  throw new Error("Some error message");
+});
+
+self.onerror = (...args) => {
+  console.log("Arguments from self.onerror:", args);
+  return true;
+};
+
+self.addEventListener("error", (evt) => {
+  // Returning true from self.onerror means that subsequent event listeners
+  // should see the event as canceled.
+  console.log("Is event canceled?:", evt.defaultPrevented);
+
+  self.close();
+});