1 files changed, 62 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/events/EventTarget-constructible.any.js b/testing/web-platform/tests/dom/events/EventTarget-constructible.any.js
new file mode 100644
index 0000000000..b0e7614e62
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-constructible.any.js
@@ -0,0 +1,62 @@
+"use strict";
+
+test(() => {
+  const target = new EventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  function listener(e) {
+    assert_equals(e, event);
+    ++callCount;
+  }
+
+  target.addEventListener("foo", listener);
+
+  target.dispatchEvent(event);
+  assert_equals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assert_equals(callCount, 2);
+
+  target.removeEventListener("foo", listener);
+  target.dispatchEvent(event);
+  assert_equals(callCount, 2);
+}, "A constructed EventTarget can be used as expected");
+
+test(() => {
+  class NicerEventTarget extends EventTarget {
+    on(...args) {
+      this.addEventListener(...args);
+    }
+
+    off(...args) {
+      this.removeEventListener(...args);
+    }
+
+    dispatch(type, detail) {
+      this.dispatchEvent(new CustomEvent(type, { detail }));
+    }
+  }
+
+  const target = new NicerEventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  const detail = "some data";
+  let callCount = 0;
+
+  function listener(e) {
+    assert_equals(e.detail, detail);
+    ++callCount;
+  }
+
+  target.on("foo", listener);
+
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 1);
+
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 2);
+
+  target.off("foo", listener);
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 2);
+}, "EventTarget can be subclassed");