From 6cf2234a57450fdc19ffa373df9cecfce74fb8c0 Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Tue, 2 Jul 2019 16:58:46 +0100
Subject: [PATCH] [Flare] Do not block mouse presses on scroll (#16033)

---
 packages/react-events/src/dom/Press.js        |  9 +++++++--
 .../src/dom/__tests__/Press-test.internal.js  | 20 +++++++++++++++++--
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/packages/react-events/src/dom/Press.js b/packages/react-events/src/dom/Press.js
index c8738521ce..20be59f10c 100644
--- a/packages/react-events/src/dom/Press.js
+++ b/packages/react-events/src/dom/Press.js
@@ -797,6 +797,7 @@ const PressResponder: ReactDOMEventResponder = {
     const nativeEvent: any = event.nativeEvent;
     const isPressed = state.isPressed;
     const activePointerId = state.activePointerId;
+    const previousPointerType = state.pointerType;
 
     handleStopPropagation(props, context, nativeEvent);
     switch (type) {
@@ -807,7 +808,7 @@ const PressResponder: ReactDOMEventResponder = {
         let touchEvent;
         // Ignore emulated events (pointermove will dispatch touch and mouse events)
         // Ignore pointermove events during a keyboard press.
-        if (state.pointerType !== pointerType) {
+        if (previousPointerType !== pointerType) {
           return;
         }
         if (type === 'pointermove' && activePointerId !== pointerId) {
@@ -976,7 +977,7 @@ const PressResponder: ReactDOMEventResponder = {
 
       case 'click': {
         // "keyup" occurs after "click"
-        if (state.pointerType !== 'keyboard') {
+        if (previousPointerType !== 'keyboard') {
           removeRootEventTypes(context, state);
         }
         break;
@@ -984,6 +985,10 @@ const PressResponder: ReactDOMEventResponder = {
 
       // CANCEL
       case 'scroll': {
+        // We ignore incoming scroll events when using mouse events
+        if (previousPointerType === 'mouse') {
+          return;
+        }
         const pressTarget = state.pressTarget;
         const scrollTarget = nativeEvent.target;
         const doc = context.getActiveDocument();
diff --git a/packages/react-events/src/dom/__tests__/Press-test.internal.js b/packages/react-events/src/dom/__tests__/Press-test.internal.js
index e7e3b9b117..bbee5b5cae 100644
--- a/packages/react-events/src/dom/__tests__/Press-test.internal.js
+++ b/packages/react-events/src/dom/__tests__/Press-test.internal.js
@@ -2445,15 +2445,31 @@ describe('Event responder: Press', () => {
       );
       ReactDOM.render(element, container);
 
-      ref.current.dispatchEvent(createEvent('pointerdown'));
+      // Should cancel for non-mouse events
+      ref.current.dispatchEvent(
+        createEvent('pointerdown', {
+          pointerType: 'touch',
+        }),
+      );
       ref.current.dispatchEvent(createEvent('scroll'));
       expect(onPressEnd).toHaveBeenCalledTimes(1);
       jest.runAllTimers();
       expect(onLongPress).not.toBeCalled();
 
-      onLongPress.mockReset();
       onPressEnd.mockReset();
 
+      // Should not cancel for mouse events
+      ref.current.dispatchEvent(
+        createEvent('pointerdown', {
+          pointerType: 'mouse',
+        }),
+      );
+      ref.current.dispatchEvent(createEvent('scroll'));
+      expect(onPressEnd).toHaveBeenCalledTimes(0);
+      jest.runAllTimers();
+
+      onLongPress.mockReset();
+
       // When pointer events are supported
       ref.current.dispatchEvent(
         createEvent('pointerdown', {