introduce a private API for RCTHost to refresh its bundle url (#37567)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/37567

Changelog: [Internal]

in the situation where we want to refresh the bundle url due to developer mode, we add a private API that allows the host to refresh its bundle URL if needed. this private API will be called on cmd + R, which is the only case that supports the changing bundle URL in the middle of the app session.

Reviewed By: cipolleschi

Differential Revision: D45937856

fbshipit-source-id: 718047abcbce983c4f820eb550d6fce05d03bfee

packages/react-native/ReactCommon/react/bridgeless/platform/ios/Core/RCTHost+Internal.h

@@ -7,8 +7,11 @@
 
 #import "RCTHost.h"
 
+typedef NSURL * (^RCTHostBundleURLProvider)(void);
+
 @interface RCTHost (Internal)
 
 - (void)registerSegmentWithId:(NSNumber *)segmentId path:(NSString *)path;
+- (void)setBundleURLProvider:(RCTHostBundleURLProvider)bundleURLProvider;
 
 @end

packages/react-native/ReactCommon/react/bridgeless/platform/ios/Core/RCTHost.h

@@ -29,7 +29,6 @@ typedef std::shared_ptr<facebook::react::JSEngineInstance> (^RCTHostJSEngineProv
 
 @protocol RCTHostDelegate <NSObject>
 
-- (NSURL *)getBundleURL;
 - (std::shared_ptr<facebook::react::ContextContainer>)createContextContainer;
 
 - (void)host:(RCTHost *)host

packages/react-native/ReactCommon/react/bridgeless/platform/ios/Core/RCTHost.mm

@@ -30,6 +30,7 @@ using namespace facebook::react;
   NSURL *_oldDelegateBundleURL;
   NSURL *_bundleURL;
   RCTBundleManager *_bundleManager;
+  RCTHostBundleURLProvider _bundleURLProvider;
   facebook::react::ReactInstance::BindingsInstallFunc _bindingsInstallFunc;
   RCTHostJSEngineProvider _jsEngineProvider;
 
@@ -86,11 +87,11 @@ using namespace facebook::react;
     auto defaultBundleURLGetter = ^NSURL *()
     {
       RCTHost *strongSelf = weakSelf;
-      if (!strongSelf) {
+      if (!strongSelf || !strongSelf->_bundleURLProvider) {
         return nil;
       }
 
-      return [strongSelf->_hostDelegate getBundleURL];
+      return strongSelf->_bundleURLProvider();
     };
 
     [self _setBundleURL:bundleURL];
@@ -200,7 +201,9 @@ using namespace facebook::react;
 {
   [_instance invalidate];
   _instance = nil;
-  [self _setBundleURL:[_hostDelegate getBundleURL]];
+  if (_bundleURLProvider) {
+    [self _setBundleURL:_bundleURLProvider()];
+  }
 
   // Ensure all attached surfaces are restarted after reload
   {
@@ -265,6 +268,11 @@ using namespace facebook::react;
   [_instance registerSegmentWithId:segmentId path:path];
 }
 
+- (void)setBundleURLProvider:(RCTHostBundleURLProvider)bundleURLProvider
+{
+  _bundleURLProvider = [bundleURLProvider copy];
+}
+
 #pragma mark - Private
 
 - (void)_attachSurface:(RCTFabricSurface *)surface FB_OBJC_DIRECT