Mark connectivity closures as nullable and check null when invoking them

2 files changed, 7 insertions, 6 deletions

diff --git a/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.h b/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.h
index be58138c78..e341b6ef6c 100644
--- a/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.h
+++ b/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.h
@@ -72,6 +72,6 @@
  * Only one handler is active at a time, so if this method is called again before the previous
  * handler has been called, it might never be called at all (or yes, if it has already been queued).
  */
-- (void)handleLossWithHandler:(void (^)())lossHandler
-      wifiStatusChangeHandler:(void (^)())wifiStatusChangeHandler;
+- (void)handleLossWithHandler:(nullable void (^)())lossHandler
+      wifiStatusChangeHandler:(nullable void (^)())wifiStatusChangeHandler;
 @end
diff --git a/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m b/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m
index c6f6b39b61..40afca2d3d 100644
--- a/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m
+++ b/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m
@@ -151,15 +151,16 @@ static void PassFlagsToContextInfoBlock(SCNetworkReachabilityRef target,
   return returnValue;
 }
 
-- (void)handleLossWithHandler:(void (^)())lossHandler
-      wifiStatusChangeHandler:(void (^)())wifiStatusChangeHandler {
+- (void)handleLossWithHandler:(nullable void (^)())lossHandler
+      wifiStatusChangeHandler:(nullable void (^)())wifiStatusChangeHandler {
   __weak typeof(self) weakSelf = self;
   [self startListeningWithHandler:^(GRPCReachabilityFlags *flags) {
     typeof(self) strongSelf = weakSelf;
     if (strongSelf) {
-      if (!flags.reachable) {
+      if (lossHandler && !flags.reachable) {
         lossHandler();
-      } else if (strongSelf->_previousReachabilityFlags &&
+      } else if (wifiStatusChangeHandler &&
+                 strongSelf->_previousReachabilityFlags &&
                  (flags.isWWAN ^
                   strongSelf->_previousReachabilityFlags.isWWAN)) {
         wifiStatusChangeHandler();