test: add test specs.

bridge/core/html/html_anchor_element.d.ts

@@ -1,6 +1,7 @@
 import {Element} from "../dom/element";
+import {HTMLElement} from "./html_element";
 
-interface HTMLAnchorElement extends Element {
+interface HTMLAnchorElement extends HTMLElement {
   target: DartImpl<string>;
   accessKey: DartImpl<string>;
   download: DartImpl<string>;

integration_tests/specs/dom/events/event.ts

@@ -786,4 +786,42 @@ describe('Event', () => {
     el.style.width = '102px';
     el2.style.width = '102px';
   });
+
+  it('should works with preventDefault in `<a /> element', async (done) => {
+    const anchorElement = createElement('a', {}, [createText('')]);
+    BODY.append(anchorElement);
+
+    anchorElement.addEventListener('click', async (e) => {
+      e.preventDefault();
+
+      BODY.append(createText('Nothing happened'));
+
+      await snapshot();
+      done();
+    });
+
+    anchorElement.click();
+  });
+
+  it('should satisfy react-router event check', (done) => {
+    function isModifiedEvent(event: MouseEvent) {
+      return !!(event.metaKey || event.altKey || event.ctrlKey || event.shiftKey);
+    }
+    function shouldProcessLinkClick(event: MouseEvent) {
+      return event.button === 0 &&
+        // Let browser handle "target=_blank" etc.
+        !isModifiedEvent(event) // Ignore clicks with modifier keys
+        ;
+    }
+
+    const anchorElement = createElement('a', {}, []);
+    BODY.append(anchorElement);
+
+    anchorElement.addEventListener('click', async (e) => {
+      expect(shouldProcessLinkClick(e));
+      done();
+    });
+
+    anchorElement.click();
+  });
 });

webf/lib/src/dom/window.dart

@@ -142,12 +142,6 @@ class Window extends EventTarget {
     _watchedViewportElements.clear();
   }
 
-  @override
-  void dispose() {
-    super.dispose();
-    _watchedViewportElements.clear();
-  }
-
   @override
   void removeEventListener(String eventType, EventHandler handler, {bool isCapture = false, bool builtInCallback = false}) {
     super.removeEventListener(eventType, handler, isCapture: isCapture);