iOS: Make each module implement getTurboModuleWithJsInvoker: instead of having centralized provider

Summary:
For better modularity, each module conforming to RCTTurboModule should provide a getter for the specific TurboModule instance for itself. This is a bit more extra work for devs, but simplify tooling and allow better modularity vs having a central function that provides the correct instance based on name.

Note: Android may or may not follow this new pattern -- TBD.

Reviewed By: RSNara

Differential Revision: D13882073

fbshipit-source-id: 6d5f82af67278c39c43c4f7970995690d4a82a98

React/Base/RCTBridgeModule.h

@@ -326,7 +326,6 @@ RCT_EXTERN void RCTRegisterModule(Class); \
  * Experimental.
  * A protocol to declare that a class supports TurboModule.
  * This may be removed in the future.
+ * See RCTTurboModule.h for actual signature.
  */
-@protocol RCTTurboModule <NSObject>
-
-@end
+@protocol RCTTurboModule;

ReactCommon/turbomodule/core/platform/ios/RCTTurboModule.h

@@ -38,19 +38,18 @@ public:
 } // namespace react
 } // namespace facebook
 
+@protocol RCTTurboModule <NSObject>
+
+@optional
+
+// This should be required, after migration is done.
+- (std::shared_ptr<facebook::react::TurboModule>)getTurboModuleWithJsInvoker:(std::shared_ptr<facebook::react::JSCallInvoker>)jsInvoker;
+
+@end
+
 // TODO: Consolidate this extension with the one in RCTSurfacePresenter.
 @interface RCTBridge ()
 
 - (std::shared_ptr<facebook::react::MessageQueueThread>)jsMessageThread;
 
 @end
-
-/**
- * A backward-compatible protocol to be adopted by an existing RCTCxxModule-based class
- * so that it can support the TurboModule system.
- */
-@protocol RCTTurboCxxModule <RCTTurboModule>
-
-- (std::shared_ptr<facebook::react::TurboModule>)getTurboModuleWithJsInvoker:(std::shared_ptr<facebook::react::JSCallInvoker>)jsInvoker;
-
-@end

ReactCommon/turbomodule/core/platform/ios/RCTTurboModuleManager.mm

@@ -111,17 +111,18 @@ static Class getFallbackClassFromName(const char *name) {
         }
       }
 
+      if ([module respondsToSelector:@selector(getTurboModuleWithJsInvoker:)]) {
+        return [module getTurboModuleWithJsInvoker:strongSelf->_jsInvoker];
+      }
+
       // RCTCxxModule compatibility layer.
       if ([moduleClass isSubclassOfClass:RCTCxxModule.class]) {
-        if ([module respondsToSelector:@selector(getTurboModuleWithJsInvoker:)]) {
-          return [((id<RCTTurboCxxModule>)module) getTurboModuleWithJsInvoker:strongSelf->_jsInvoker];
-        }
-
         // Use TurboCxxModule compat class to wrap the CxxModule instance.
         // This is only for migration convenience, despite less performant.
         return std::make_shared<react::TurboCxxModule>([((RCTCxxModule *)module) createModule], strongSelf->_jsInvoker);
       }
 
+      // This may be needed for migration purpose in case the module class doesn't provide the static getter.
       return [strongSelf->_delegate getTurboModule:name instance:module jsInvoker:strongSelf->_jsInvoker];
     };