3 files changed, 73 insertions, 2 deletions
diff --git a/cli/tests/subdir/event_worker_scope.js b/cli/tests/subdir/event_worker_scope.js
new file mode 100644
index 000000000..0381801a8
--- /dev/null
+++ b/cli/tests/subdir/event_worker_scope.js
@@ -0,0 +1,43 @@
+let messageHandlersCalled = 0;
+let errorHandlersCalled = 0;
+
+onmessage = function (e) {
+  if (e.data === "boom") {
+    throw new Error("boom error!");
+  }
+  messageHandlersCalled++;
+};
+
+self.addEventListener("message", (_e) => {
+  messageHandlersCalled++;
+});
+
+self.addEventListener("message", (_e) => {
+  messageHandlersCalled++;
+});
+
+self.addEventListener("message", (_e) => {
+  messageHandlersCalled++;
+
+  postMessage({
+    messageHandlersCalled,
+    errorHandlersCalled,
+  });
+});
+
+onerror = function (_e) {
+  errorHandlersCalled++;
+};
+
+self.addEventListener("error", (_e) => {
+  errorHandlersCalled++;
+});
+
+self.addEventListener("error", (_e) => {
+  errorHandlersCalled++;
+});
+
+self.addEventListener("error", (e) => {
+  errorHandlersCalled++;
+  e.preventDefault();
+});
diff --git a/cli/tests/workers_test.out b/cli/tests/workers_test.out
index 541adc20f..d3c25d3dd 100644
--- a/cli/tests/workers_test.out
+++ b/cli/tests/workers_test.out
@@ -1,4 +1,4 @@
-running 7 tests
+running 8 tests
 test worker terminate ... ok [WILDCARD]
 test worker nested ... ok [WILDCARD]
 test worker throws when executing ... ok [WILDCARD]
@@ -6,5 +6,6 @@ test worker fetch API ... ok [WILDCARD]
 test worker terminate busy loop ... ok [WILDCARD]
 test worker race condition ... ok [WILDCARD]
 test worker is event listener ... ok [WILDCARD]
+test worker scope is event listener ... ok [WILDCARD]
 
-test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out [WILDCARD]
+test result: ok. 8 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out [WILDCARD]
diff --git a/cli/tests/workers_test.ts b/cli/tests/workers_test.ts
index bb00d67fd..d18186658 100644
--- a/cli/tests/workers_test.ts
+++ b/cli/tests/workers_test.ts
@@ -231,3 +231,30 @@ Deno.test({
     worker.terminate();
   },
 });
+
+Deno.test({
+  name: "worker scope is event listener",
+  fn: async function (): Promise<void> {
+    const promise1 = createResolvable();
+
+    const worker = new Worker("../tests/subdir/event_worker_scope.js", {
+      type: "module",
+    });
+
+    worker.onmessage = (e: MessageEvent): void => {
+      const { messageHandlersCalled, errorHandlersCalled } = e.data;
+      assertEquals(messageHandlersCalled, 4);
+      assertEquals(errorHandlersCalled, 4);
+      promise1.resolve();
+    };
+
+    worker.onerror = (_e): void => {
+      throw new Error("unreachable");
+    };
+
+    worker.postMessage("boom");
+    worker.postMessage("ping");
+    await promise1;
+    worker.terminate();
+  },
+});