fix(iOS) [0.74]: RCTRedBox not appearing in Bridgeless when metro is not running

packages/react-native/React/CoreModules/RCTRedBox.mm

@@ -274,7 +274,13 @@ - (void)dismiss
 
 - (void)reload
 {
-  [_actionDelegate reloadFromRedBoxController:self];
+  if (_actionDelegate != nil) {
+   [_actionDelegate reloadFromRedBoxController:self];
+  } else {
+    // In bridgeless mode `RCTRedBox` gets deallocted, we need to notify listeners anyway.
+    RCTTriggerReloadCommandListeners(@"Redbox");
+    [self dismiss];
+  }
 }
 
 - (void)showExtraDataViewController

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.mm

@@ -24,7 +24,9 @@
 #import <React/RCTEventDispatcherProtocol.h>
 #import <React/RCTFollyConvert.h>
 #import <React/RCTJavaScriptLoader.h>
+#import <React/RCTReloadCommand.h>
 #import <React/RCTLog.h>
+#import <React/RCTRedBox.h>
 #import <React/RCTLogBox.h>
 #import <React/RCTModuleData.h>
 #import <React/RCTPerformanceLogger.h>
@@ -121,11 +123,18 @@ - (instancetype)initWithDelegate:(id<RCTInstanceDelegate>)delegate
             [weakSelf callFunctionOnJSModule:moduleName method:methodName args:args];
           }];
     }
-
-    [[NSNotificationCenter defaultCenter] addObserver:self
-                                             selector:@selector(_notifyEventDispatcherObserversOfEvent_DEPRECATED:)
-                                                 name:@"RCTNotifyEventDispatcherObserversOfEvent_DEPRECATED"
-                                               object:nil];
+
+    NSNotificationCenter *defaultCenter = [NSNotificationCenter defaultCenter];
+
+    [defaultCenter addObserver:self
+               selector:@selector(_notifyEventDispatcherObserversOfEvent_DEPRECATED:)
+                   name:@"RCTNotifyEventDispatcherObserversOfEvent_DEPRECATED"
+                 object:nil];
+
+    [defaultCenter addObserver:self
+                      selector:@selector(didReceiveReloadCommand)
+                          name:RCTTriggerReloadCommandNotification
+                        object:nil];
 
     [self _start];
   }
@@ -389,6 +398,27 @@ - (void)_attachBridgelessAPIsToModule:(id<RCTTurboModule>)module
   }
 }
 
+- (void)handleError:(NSError *)error
+{
+  if (!_valid) {
+    return;
+  }
+
+  RCTRedBox *redBox = [self->_turboModuleManager moduleForName:"RedBox"];
+
+  RCTExecuteOnMainQueue(^{
+    [[NSNotificationCenter defaultCenter] postNotificationName:RCTJavaScriptDidFailToLoadNotification
+                                                         object:self
+                                                       userInfo:@{@"error": error}];
+
+    // TODO: Attach error raw stack RCTJSRawStackTraceKey
+    [redBox showErrorMessage:[error localizedDescription]];
+
+    RCTFatal(error);
+  });
+}
+
+
 - (void)_loadJSBundle:(NSURL *)sourceURL
 {
 #if RCT_DEV_MENU && __has_include(<React/RCTDevLoadingViewProtocol.h>)
@@ -420,8 +450,7 @@ - (void)_loadJSBundle:(NSURL *)sourceURL
         }
 
         if (error) {
-          // TODO(T91461138): Properly address bundle loading errors.
-          RCTLogError(@"RCTInstance: Error while loading bundle: %@", error);
+          [strongSelf handleError:error];
           [strongSelf invalidate];
           return;
         }
@@ -446,6 +475,7 @@ - (void)_loadScriptFromSource:(RCTSource *)source
   const auto *url = deriveSourceURL(source.url).UTF8String;
   _reactInstance->loadScript(std::move(script), url);
   [[NSNotificationCenter defaultCenter] postNotificationName:@"RCTInstanceDidLoadBundle" object:nil];
+
 
   if (_onInitialBundleLoad) {
     _onInitialBundleLoad();
@@ -490,4 +520,8 @@ - (void)_handleJSErrorMap:(facebook::react::MapBuffer)errorMap
                      isFatal:errorMap.getBool(JSErrorHandlerKey::kIsFatal)];
 }
 
+- (void)didReceiveReloadCommand { 
+  [self _loadJSBundle:[self->_bridgeModuleDecorator.bundleManager bundleURL]];
+}
+
 @end