Fix a crash when keyboard is visible and bridge reload happens

Reviewed By: sahrens

Differential Revision: D6573855

fbshipit-source-id: 8768dca7d36782e82fb457f6ff4b09791e669d00

Author: fromcelticpark

React/Modules/RCTEventEmitter.m

@@ -37,9 +37,10 @@ + (void)initialize
 
 - (void)sendEventWithName:(NSString *)eventName body:(id)body
 {
-  RCTAssert(_bridge != nil, @"bridge is not set. This is probably because you've "
+  RCTAssert(_bridge != nil, @"Error when sending event: %@ with body: %@. "
+            "Bridge is not set. This is probably because you've "
             "explicitly synthesized the bridge in %@, even though it's inherited "
-            "from RCTEventEmitter.", [self class]);
+            "from RCTEventEmitter.", eventName, body, [self class]);
 
   if (RCT_DEBUG && ![[self supportedEvents] containsObject:eventName]) {
     RCTLogError(@"`%@` is not a supported event type for %@. Supported events are: `%@`",

React/Modules/RCTKeyboardObserver.m

@@ -54,9 +54,15 @@ - (void)stopObserving
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 }
 
+// Bridge might be already invalidated by the time the keyboard is about to be dismissed.
+// This might happen, for example, when reload from the packager is performed.
+// Thus we need to check against nil here.
 #define IMPLEMENT_KEYBOARD_HANDLER(EVENT) \
 - (void)EVENT:(NSNotification *)notification \
 { \
+  if (!self.bridge) { \
+    return; \
+  } \
   [self sendEventWithName:@#EVENT \
     body:RCTParseKeyboardNotification(notification)]; \
 }