Add null check for context in redbox surface delegate

Summary:
The context could be null or is finishing when we create the redbox surface content view. This diff adds the null check and delegate the message in log when context is not available.

Changelog:
[Android][Fixed] - Adding null check for context in redbox surface delegate

Differential Revision: D34930595

fbshipit-source-id: 91508ded7821033abcd893f70bcfe3cc9ee5b5c2

Author: ryancat

ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerBase.java

@@ -343,6 +343,9 @@ private void showNewError(
         new Runnable() {
           @Override
           public void run() {
+            // Keep a copy of the latest error to be shown by the RedBoxSurface
+            updateLastErrorInfo(message, stack, errorCookie, errorType);
+
             if (mRedBoxSurfaceDelegate == null) {
               @Nullable SurfaceDelegate redBoxSurfaceDelegate = createSurfaceDelegate("RedBox");
               if (redBoxSurfaceDelegate != null) {
@@ -361,8 +364,6 @@ public void run() {
               return;
             }
 
-            // The RedBox surface delegate will always show the latest error
-            updateLastErrorInfo(message, stack, errorCookie, errorType);
             mRedBoxSurfaceDelegate.show();
           }
         });

ReactAndroid/src/main/java/com/facebook/react/devsupport/RedBoxDialogSurfaceDelegate.java

@@ -42,6 +42,15 @@ public void createContentView(String appKey) {
     // used here.
     RedBoxHandler redBoxHandler = mDevSupportManager.getRedBoxHandler();
     Activity context = mDevSupportManager.getCurrentActivity();
+    if (context == null || context.isFinishing()) {
+      @Nullable String message = mDevSupportManager.getLastErrorTitle();
+      FLog.e(
+          ReactConstants.TAG,
+          "Unable to launch redbox because react activity "
+              + "is not available, here is the error that redbox would've displayed: "
+              + (message != null ? message : "N/A"));
+      return;
+    }
     // Create a new RedBox when currentActivity get updated
     mRedBoxContentView = new RedBoxContentView(context);
     mRedBoxContentView