Fabric: Post RCTInstanceDidLoadBundle notification after bundle loaded (#48082)

Summary:
Fixes #47949

## Changelog:

[IOS] [FIXED] - Fabric: Post RCTInstanceDidLoadBundle notification after bundle loaded

Pull Request resolved: #48082

Test Plan: Post RCTInstanceDidLoadBundle notification after bundle loaded

Reviewed By: philIip

Differential Revision: D66754060

Pulled By: cipolleschi

fbshipit-source-id: d30f0ed73e127936082e6f91e137b9b4013c6651

Author: zhongwuzw

packages/react-native/ReactCommon/react/runtime/ReactInstance.cpp

@@ -236,47 +236,51 @@ std::string simpleBasename(const std::string& path) {
  */
 void ReactInstance::loadScript(
     std::unique_ptr<const JSBigString> script,
-    const std::string& sourceURL) {
+    const std::string& sourceURL,
+    std::function<void(jsi::Runtime& runtime)>&& completion) {
   auto buffer = std::make_shared<BigStringBuffer>(std::move(script));
   std::string scriptName = simpleBasename(sourceURL);
 
-  runtimeScheduler_->scheduleWork(
-      [this,
-       scriptName,
-       sourceURL,
-       buffer = std::move(buffer),
-       weakBufferedRuntimeExecuter = std::weak_ptr<BufferedRuntimeExecutor>(
-           bufferedRuntimeExecutor_)](jsi::Runtime& runtime) {
-        SystraceSection s("ReactInstance::loadScript");
-        bool hasLogger(ReactMarker::logTaggedMarkerBridgelessImpl);
-        if (hasLogger) {
-          ReactMarker::logTaggedMarkerBridgeless(
-              ReactMarker::RUN_JS_BUNDLE_START, scriptName.c_str());
-        }
+  runtimeScheduler_->scheduleWork([this,
+                                   scriptName,
+                                   sourceURL,
+                                   buffer = std::move(buffer),
+                                   weakBufferedRuntimeExecuter =
+                                       std::weak_ptr<BufferedRuntimeExecutor>(
+                                           bufferedRuntimeExecutor_),
+                                   completion](jsi::Runtime& runtime) {
+    SystraceSection s("ReactInstance::loadScript");
+    bool hasLogger(ReactMarker::logTaggedMarkerBridgelessImpl);
+    if (hasLogger) {
+      ReactMarker::logTaggedMarkerBridgeless(
+          ReactMarker::RUN_JS_BUNDLE_START, scriptName.c_str());
+    }
 
-        runtime.evaluateJavaScript(buffer, sourceURL);
+    runtime.evaluateJavaScript(buffer, sourceURL);
 
-        /**
-         * TODO(T183610671): We need a safe/reliable way to enable the js
-         * pipeline from javascript. Remove this after we figure that out, or
-         * after we just remove the js pipeline.
-         */
-        if (!jsErrorHandler_->hasHandledFatalError()) {
-          jsErrorHandler_->setRuntimeReady();
-        }
+    /**
+     * TODO(T183610671): We need a safe/reliable way to enable the js
+     * pipeline from javascript. Remove this after we figure that out, or
+     * after we just remove the js pipeline.
+     */
+    if (!jsErrorHandler_->hasHandledFatalError()) {
+      jsErrorHandler_->setRuntimeReady();
+    }
 
-        if (hasLogger) {
-          ReactMarker::logTaggedMarkerBridgeless(
-              ReactMarker::RUN_JS_BUNDLE_STOP, scriptName.c_str());
-          ReactMarker::logMarkerBridgeless(
-              ReactMarker::INIT_REACT_RUNTIME_STOP);
-          ReactMarker::logMarkerBridgeless(ReactMarker::APP_STARTUP_STOP);
-        }
-        if (auto strongBufferedRuntimeExecuter =
-                weakBufferedRuntimeExecuter.lock()) {
-          strongBufferedRuntimeExecuter->flush();
-        }
-      });
+    if (hasLogger) {
+      ReactMarker::logTaggedMarkerBridgeless(
+          ReactMarker::RUN_JS_BUNDLE_STOP, scriptName.c_str());
+      ReactMarker::logMarkerBridgeless(ReactMarker::INIT_REACT_RUNTIME_STOP);
+      ReactMarker::logMarkerBridgeless(ReactMarker::APP_STARTUP_STOP);
+    }
+    if (auto strongBufferedRuntimeExecuter =
+            weakBufferedRuntimeExecuter.lock()) {
+      strongBufferedRuntimeExecuter->flush();
+    }
+    if (completion) {
+      completion(runtime);
+    }
+  });
 }
 
 /*

packages/react-native/ReactCommon/react/runtime/ReactInstance.h

@@ -49,7 +49,8 @@ class ReactInstance final : private jsinspector_modern::InstanceTargetDelegate {
 
   void loadScript(
       std::unique_ptr<const JSBigString> script,
-      const std::string& sourceURL);
+      const std::string& sourceURL,
+      std::function<void(jsi::Runtime& runtime)>&& completion = nullptr);
 
   void registerSegment(uint32_t segmentId, const std::string& segmentPath);
 

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

@@ -472,8 +472,9 @@ - (void)_loadScriptFromSource:(RCTSource *)source
 
   auto script = std::make_unique<NSDataBigString>(source.data);
   const auto *url = deriveSourceURL(source.url).UTF8String;
-  _reactInstance->loadScript(std::move(script), url);
-  [[NSNotificationCenter defaultCenter] postNotificationName:@"RCTInstanceDidLoadBundle" object:nil];
+  _reactInstance->loadScript(std::move(script), url, [](jsi::Runtime &_) {
+    [[NSNotificationCenter defaultCenter] postNotificationName:@"RCTInstanceDidLoadBundle" object:nil];
+  });
 }
 
 - (void)_handleJSError:(const JsErrorHandler::ParsedError &)error withRuntime:(jsi::Runtime &)runtime