Event API: ensure preventDefault works for nested targets (#15633)

packages/react-dom/src/events/DOMEventResponderSystem.js

@@ -208,6 +208,7 @@ const eventResponderContext: ReactResponderContext = {
     childTarget: Element | Document,
     parentTarget: Element | Document,
   ): boolean {
+    validateResponderContext();
     const childFiber = getClosestInstanceFromNode(childTarget);
     const parentFiber = getClosestInstanceFromNode(parentTarget);
 
@@ -345,6 +346,7 @@ const eventResponderContext: ReactResponderContext = {
     }
   },
   getFocusableElementsInScope(): Array<HTMLElement> {
+    validateResponderContext();
     const focusableElements = [];
     const eventComponentInstance = ((currentInstance: any): ReactEventComponentInstance);
     let node = ((eventComponentInstance.currentFiber: any): Fiber).child;
@@ -383,6 +385,7 @@ const eventResponderContext: ReactResponderContext = {
   getEventPointerType(
     event: ReactResponderEvent,
   ): '' | 'mouse' | 'keyboard' | 'pen' | 'touch' {
+    validateResponderContext();
     const nativeEvent: any = event.nativeEvent;
     const {type, pointerType} = nativeEvent;
     if (pointerType != null) {
@@ -400,6 +403,7 @@ const eventResponderContext: ReactResponderContext = {
     return '';
   },
   getEventCurrentTarget(event: ReactResponderEvent): Element {
+    validateResponderContext();
     const target: any = event.target;
     let currentTarget = target;
     while (
@@ -412,8 +416,26 @@ const eventResponderContext: ReactResponderContext = {
     return currentTarget;
   },
   getTimeStamp(): number {
+    validateResponderContext();
     return currentTimeStamp;
   },
+  isTargetWithinHostComponent(
+    target: Element | Document,
+    elementType: string,
+  ): boolean {
+    validateResponderContext();
+    let fiber = getClosestInstanceFromNode(target);
+    while (fiber !== null) {
+      if (fiber.stateNode === currentInstance) {
+        return false;
+      }
+      if (fiber.tag === HostComponent && fiber.type === elementType) {
+        return true;
+      }
+      fiber = fiber.return;
+    }
+    return false;
+  },
 };
 
 function isTargetWithinEventComponent(target: Element | Document): boolean {

packages/react-events/src/Press.js

@@ -418,10 +418,6 @@ function dispatchCancel(
   }
 }
 
-function isAnchorTagElement(eventTarget: EventTarget): boolean {
-  return (eventTarget: any).nodeName === 'A';
-}
-
 function isValidKeyPress(key: string): boolean {
   // Accessibility for keyboards. Space and Enter only.
   return key === ' ' || key === 'Enter';
@@ -673,7 +669,7 @@ const PressResponder = {
       }
 
       case 'click': {
-        if (isAnchorTagElement(target)) {
+        if (context.isTargetWithinHostComponent(target, 'a')) {
           const {
             altKey,
             ctrlKey,

packages/react-events/src/__tests__/Press-test.internal.js

@@ -1965,6 +1965,25 @@ describe('Event responder: Press', () => {
       expect(preventDefault).toBeCalled();
     });
 
+    it('prevents native behaviour by default with nested elements', () => {
+      const onPress = jest.fn();
+      const preventDefault = jest.fn();
+      const ref = React.createRef();
+      const element = (
+        <Press onPress={onPress}>
+          <a href="#">
+            <div ref={ref} />
+          </a>
+        </Press>
+      );
+      ReactDOM.render(element, container);
+
+      ref.current.dispatchEvent(createEvent('pointerdown'));
+      ref.current.dispatchEvent(createEvent('pointerup'));
+      ref.current.dispatchEvent(createEvent('click', {preventDefault}));
+      expect(preventDefault).toBeCalled();
+    });
+
     it('uses native behaviour for interactions with modifier keys', () => {
       const onPress = jest.fn();
       const preventDefault = jest.fn();

packages/shared/ReactTypes.js

@@ -194,4 +194,8 @@ export type ReactResponderContext = {
   ): '' | 'mouse' | 'keyboard' | 'pen' | 'touch',
   getEventCurrentTarget(event: ReactResponderEvent): Element,
   getTimeStamp: () => number,
+  isTargetWithinHostComponent: (
+    target: Element | Document,
+    elementType: string,
+  ) => boolean,
 };