Fabric: Checking an EventEmitter before calling in RCTModalHostViewComponentView

Summary: We need to check if `_eventEmitter` is not nullptr before each call on it.

Reviewed By: sammy-SC

Differential Revision: D17531070

fbshipit-source-id: e9b5608845c10c7c2ef38f43c8deb67dad10fb6f

Author: shergin

React/Fabric/Mounting/ComponentViews/Modal/RCTModalHostViewComponentView.mm

@@ -129,8 +129,13 @@ - (void)ensurePresentedOnlyIfNeeded
         presentViewController:_viewController
                      animated:_shouldAnimatePresentation
                    completion:^{
-                     ModalHostViewOnShowStruct onShow;
-                     std::dynamic_pointer_cast<const ModalHostViewEventEmitter>(self->_eventEmitter)->onShow(onShow);
+                     if (!self->_eventEmitter) {
+                       return;
+                     }
+
+                     assert(std::dynamic_pointer_cast<ModalHostViewEventEmitter const>(self->_eventEmitter));
+                     auto eventEmitter = std::static_pointer_cast<ModalHostViewEventEmitter const>(self->_eventEmitter);
+                     eventEmitter->onShow(ModalHostViewOnShowStruct{});
                    }];
   }
 
@@ -156,8 +161,12 @@ - (void)didMoveToSuperview
 
 - (void)boundsDidChange:(CGRect)newBounds
 {
-  std::dynamic_pointer_cast<const ModalHostViewEventEmitter>(_eventEmitter)
-      ->onOrientationChange(onOrientationChangeStruct(newBounds));
+  if (_eventEmitter) {
+    assert(std::dynamic_pointer_cast<ModalHostViewEventEmitter const>(_eventEmitter));
+
+    auto eventEmitter = std::static_pointer_cast<ModalHostViewEventEmitter const>(_eventEmitter);
+    eventEmitter->onOrientationChange(onOrientationChangeStruct(newBounds));
+  }
 
   if (_state != nullptr) {
     auto newState = ModalHostViewState{RCTSizeFromCGSize(newBounds.size)};