Register RCTBridge with modern CDP backend (#42394)

Summary:
Pull Request resolved: #42394

Changelog: [Internal][iOS] - Enable stub modern CDP backend in Bridge behind a feature flag

Minimally integrates the stub native CDP backend implementation (D50936932) into iOS Bridge.

This integration registers itself as a "Modern" target (D50967794, D50967795) to instruct `inspector-proxy` to disable its CDP hacks related to source map fetching, reloads, etc. This gives us a mostly-clean slate on which to develop and test native CDP functionality.

Reviewed By: huntie

Differential Revision: D50951138

fbshipit-source-id: 8c5ad9207e73265595884380c91e38f8d0ead84d

packages/react-native/React-Core.podspec

@@ -95,6 +95,8 @@ Pod::Spec.new do |s|
     end
     ss.exclude_files = exclude_files
     ss.private_header_files   = "React/Cxx*/*.h"
+
+    ss.dependency "React-jsinspector", version
   end
 
   s.subspec "DevSupport" do |ss|

packages/react-native/React/Base/RCTBridge.mm

@@ -14,6 +14,10 @@
 #if RCT_ENABLE_INSPECTOR
 #import "RCTInspectorDevServerHelper.h"
 #endif
+#import <jsinspector-modern/InspectorFlags.h>
+#import <jsinspector-modern/InspectorInterfaces.h>
+#import <jsinspector-modern/ReactCdp.h>
+#import <optional>
 #import "RCTDevLoadingViewProtocol.h"
 #import "RCTJSThread.h"
 #import "RCTLog.h"
@@ -189,6 +193,9 @@ @interface RCTBridge () <RCTReloadListener>
 
 @implementation RCTBridge {
   NSURL *_delegateBundleURL;
+
+  std::unique_ptr<facebook::react::jsinspector_modern::PageTarget> _inspectorTarget;
+  std::optional<int> _inspectorPageId;
 }
 
 + (void)initialize
@@ -252,6 +259,11 @@ - (void)dealloc
    * RCTAssertMainQueue();
    */
   [self invalidate];
+  if (_inspectorPageId.has_value()) {
+    facebook::react::jsinspector_modern::getInspectorInstance().removePage(*_inspectorPageId);
+    _inspectorPageId.reset();
+    _inspectorTarget.reset();
+  }
 }
 
 - (void)setRCTTurboModuleRegistry:(id<RCTTurboModuleRegistry>)turboModuleRegistry
@@ -377,6 +389,29 @@ - (void)setUp
   [_performanceLogger markStartForTag:RCTPLBridgeStartup];
   [_performanceLogger markStartForTag:RCTPLTTI];
 
+  auto &inspectorFlags = facebook::react::jsinspector_modern::InspectorFlags::getInstance();
+  if (inspectorFlags.getEnableModernCDPRegistry() && !_inspectorPageId.has_value()) {
+    _inspectorTarget = std::make_unique<facebook::react::jsinspector_modern::PageTarget>();
+    __weak RCTBridge *weakSelf = self;
+    _inspectorPageId = facebook::react::jsinspector_modern::getInspectorInstance().addPage(
+        "React Native Bridge (Experimental)",
+        /* vm */ "",
+        [weakSelf](std::unique_ptr<facebook::react::jsinspector_modern::IRemoteConnection> remote)
+            -> std::unique_ptr<facebook::react::jsinspector_modern::ILocalConnection> {
+          RCTBridge *strongSelf = weakSelf;
+          if (!strongSelf) {
+            // This can happen if we're about to be dealloc'd. Reject the connection.
+            return nullptr;
+          }
+          return strongSelf->_inspectorTarget->connect(
+              std::move(remote),
+              {
+                  .integrationName = "iOS Bridge (RCTBridge)",
+              });
+        },
+        facebook::react::jsinspector_modern::InspectorPageType::Modern);
+  }
+
   Class bridgeClass = self.bridgeClass;
 
   // Only update bundleURL from delegate if delegate bundleURL has changed