diff --git a/dom/abort/event.any.js b/dom/abort/event.any.js
index 3b25702c2e4c77..a67e6f400fcf1d 100644
--- a/dom/abort/event.any.js
+++ b/dom/abort/event.any.js
@@ -17,6 +17,51 @@ test(t => {
   assert_true(s.aborted);
 
   c.abort();
-}, "AbortController() basics");
+}, "AbortController abort() should fire event synchronously");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  assert_equals(controller.signal, signal,
+                "value of controller.signal should not have changed");
+  controller.abort();
+  assert_equals(controller.signal, signal,
+                "value of controller.signal should still not have changed");
+}, "controller.signal should always return the same object");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  let eventCount = 0;
+  signal.onabort = () => {
+    ++eventCount;
+  };
+  controller.abort();
+  assert_true(signal.aborted);
+  assert_equals(eventCount, 1, "event handler should have been called once");
+  controller.abort();
+  assert_true(signal.aborted);
+  assert_equals(eventCount, 1,
+                "event handler should not have been called again");
+}, "controller.abort() should do nothing the second time it is called");
+
+test(t => {
+  const controller = new AbortController();
+  controller.abort();
+  controller.signal.onabort =
+      t.unreached_func("event handler should not be called");
+}, "event handler should not be called if added after controller.abort()");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  signal.onabort = t.step_func(e => {
+    assert_equals(e.type, "abort", "event type should be abort");
+    assert_equals(e.target, signal, "event target should be signal");
+    assert_false(e.bubbles, "event should not bubble");
+    assert_true(e.isTrusted, "event should be trusted");
+  });
+  controller.abort();
+}, "the abort event should have the right properties");
 
 done();
diff --git a/dom/interfaces.html b/dom/interfaces.html
index 8e9572d0f09ca2..3cb08f405a5a76 100644
--- a/dom/interfaces.html
+++ b/dom/interfaces.html
@@ -18,8 +18,12 @@ <h1>DOM IDL tests</h1>
 
 var idlArray = new IdlArray();
 
-function doTest(idl) {
-  idlArray.add_idls(idl);
+function doTest([html, dom]) {
+  // HTML is needed for EventHandler. Provide a dummy interface for
+  // LinkStyle which HTML depends on but we're not testing.
+  idlArray.add_untested_idls('interface LinkStyle {};');
+  idlArray.add_untested_idls(html);
+  idlArray.add_idls(dom);
   idlArray.add_objects({
     EventTarget: ['new EventTarget()'],
     Event: ['document.createEvent("Event")', 'new Event("foo")'],
@@ -46,8 +50,13 @@ <h1>DOM IDL tests</h1>
   idlArray.test();
 }
 
+function fetchText(url) {
+  return fetch(url).then((response) => response.text());
+}
+
 promise_test(function() {
-  return fetch("/interfaces/dom.idl").then(response => response.text())
-                                     .then(doTest);
+  return Promise.all(['/interfaces/html.idl',
+                      '/interfaces/dom.idl'].map(fetchText))
+                .then(doTest);
 }, "Test driver");
 </script>