Add HostCommands for resuming and stepping debugger

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

@@ -199,6 +199,11 @@ void onReload(const PageReloadRequest &request) override
     [bridge_ reload];
   }
 
+  void onSetPausedInDebuggerMessage(const OverlaySetPausedInDebuggerMessageRequest &) override
+  {
+    // TODO(moti): Implement this
+  }
+
  private:
   __weak RCTBridge *bridge_;
 };

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -1175,6 +1175,7 @@ public class com/facebook/react/bridge/ReactInstanceManagerInspectorTarget : jav
 
 public abstract interface class com/facebook/react/bridge/ReactInstanceManagerInspectorTarget$TargetDelegate {
 	public abstract fun onReload ()V
+	public abstract fun onSetPausedInDebuggerMessage (Ljava/lang/String;)V
 }
 
 public class com/facebook/react/bridge/ReactMarker {
@@ -2126,6 +2127,7 @@ public abstract class com/facebook/react/devsupport/DevSupportManagerBase : com/
 	public fun handleException (Ljava/lang/Exception;)V
 	public fun hasUpToDateJSBundleInCache ()Z
 	protected fun hideDevLoadingView ()V
+	public fun hidePausedInDebuggerOverlay ()V
 	public fun hideRedboxDialog ()V
 	public fun isPackagerRunning (Lcom/facebook/react/devsupport/interfaces/PackagerStatusCallback;)V
 	public fun onNewReactContextCreated (Lcom/facebook/react/bridge/ReactContext;)V
@@ -2145,6 +2147,7 @@ public abstract class com/facebook/react/devsupport/DevSupportManagerBase : com/
 	public fun showDevOptionsDialog ()V
 	public fun showNewJSError (Ljava/lang/String;Lcom/facebook/react/bridge/ReadableArray;I)V
 	public fun showNewJavaError (Ljava/lang/String;Ljava/lang/Throwable;)V
+	public fun showPausedInDebuggerOverlay (Ljava/lang/String;)V
 	public fun startInspector ()V
 	public fun stopInspector ()V
 	public fun toggleElementInspector ()V
@@ -2290,6 +2293,7 @@ public class com/facebook/react/devsupport/ReleaseDevSupportManager : com/facebo
 	public fun handleException (Ljava/lang/Exception;)V
 	public fun handleReloadJS ()V
 	public fun hasUpToDateJSBundleInCache ()Z
+	public fun hidePausedInDebuggerOverlay ()V
 	public fun hideRedboxDialog ()V
 	public fun isPackagerRunning (Lcom/facebook/react/devsupport/interfaces/PackagerStatusCallback;)V
 	public fun loadSplitBundleFromServer (Ljava/lang/String;Lcom/facebook/react/devsupport/interfaces/DevSplitBundleCallback;)V
@@ -2309,6 +2313,7 @@ public class com/facebook/react/devsupport/ReleaseDevSupportManager : com/facebo
 	public fun showDevOptionsDialog ()V
 	public fun showNewJSError (Ljava/lang/String;Lcom/facebook/react/bridge/ReadableArray;I)V
 	public fun showNewJavaError (Ljava/lang/String;Ljava/lang/Throwable;)V
+	public fun showPausedInDebuggerOverlay (Ljava/lang/String;)V
 	public fun startInspector ()V
 	public fun stopInspector ()V
 	public fun toggleElementInspector ()V
@@ -2400,6 +2405,7 @@ public abstract interface class com/facebook/react/devsupport/interfaces/DevSupp
 	public abstract fun getSourceUrl ()Ljava/lang/String;
 	public abstract fun handleReloadJS ()V
 	public abstract fun hasUpToDateJSBundleInCache ()Z
+	public abstract fun hidePausedInDebuggerOverlay ()V
 	public abstract fun hideRedboxDialog ()V
 	public abstract fun isPackagerRunning (Lcom/facebook/react/devsupport/interfaces/PackagerStatusCallback;)V
 	public abstract fun loadSplitBundleFromServer (Ljava/lang/String;Lcom/facebook/react/devsupport/interfaces/DevSplitBundleCallback;)V
@@ -2419,6 +2425,7 @@ public abstract interface class com/facebook/react/devsupport/interfaces/DevSupp
 	public abstract fun showDevOptionsDialog ()V
 	public abstract fun showNewJSError (Ljava/lang/String;Lcom/facebook/react/bridge/ReadableArray;I)V
 	public abstract fun showNewJavaError (Ljava/lang/String;Ljava/lang/Throwable;)V
+	public abstract fun showPausedInDebuggerOverlay (Ljava/lang/String;)V
 	public abstract fun startInspector ()V
 	public abstract fun stopInspector ()V
 	public abstract fun toggleElementInspector ()V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -1494,6 +1494,15 @@ private void processPackage(
                 public void onReload() {
                   UiThreadUtil.runOnUiThread(() -> mDevSupportManager.handleReloadJS());
                 }
+
+                @Override
+                public void onSetPausedInDebuggerMessage(@Nullable String message) {
+                  if (message == null) {
+                    mDevSupportManager.hidePausedInDebuggerOverlay();
+                  } else {
+                    mDevSupportManager.showPausedInDebuggerOverlay(message);
+                  }
+                }
               });
     }
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactInstanceManagerInspectorTarget.java

@@ -10,11 +10,14 @@
 import com.facebook.jni.HybridData;
 import com.facebook.proguard.annotations.DoNotStripAny;
 import java.util.concurrent.Executor;
+import javax.annotation.Nullable;
 
 @DoNotStripAny
 public class ReactInstanceManagerInspectorTarget implements AutoCloseable {
   public interface TargetDelegate {
     public void onReload();
+
+    public void onSetPausedInDebuggerMessage(@Nullable String message);
   }
 
   private final HybridData mHybridData;

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerBase.java

@@ -1164,4 +1164,34 @@ public void openDebugger() {
     mDevServerHelper.openDebugger(
         mCurrentContext, mApplicationContext.getString(R.string.catalyst_open_debugger_error));
   }
+
+  private @Nullable AlertDialog mPausedInDebuggerDialog;
+
+  @Override
+  public void showPausedInDebuggerOverlay(String message) {
+    UiThreadUtil.runOnUiThread(
+        () -> {
+          if (mPausedInDebuggerDialog != null) {
+            mPausedInDebuggerDialog.dismiss();
+          }
+          Activity context = mReactInstanceDevHelper.getCurrentActivity();
+          if (context == null || context.isFinishing()) {
+            return;
+          }
+          mPausedInDebuggerDialog =
+              new AlertDialog.Builder(context).setMessage(message).setCancelable(false).create();
+          mPausedInDebuggerDialog.show();
+        });
+  }
+
+  @Override
+  public void hidePausedInDebuggerOverlay() {
+    UiThreadUtil.runOnUiThread(
+        () -> {
+          if (mPausedInDebuggerDialog != null) {
+            mPausedInDebuggerDialog.dismiss();
+            mPausedInDebuggerDialog = null;
+          }
+        });
+  }
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/ReleaseDevSupportManager.java

@@ -207,4 +207,10 @@ public void handleException(Exception e) {
 
   @Override
   public void openDebugger() {}
+
+  @Override
+  public void showPausedInDebuggerOverlay(String message) {}
+
+  @Override
+  public void hidePausedInDebuggerOverlay() {}
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/interfaces/DevSupportManager.kt

@@ -105,6 +105,12 @@ public interface DevSupportManager : JSExceptionHandler {
   /** Attempt to open the JS debugger on the host machine. */
   public fun openDebugger()
 
+  /** Shows the "paused in debugger" overlay with the given message. */
+  public fun showPausedInDebuggerOverlay(message: String)
+
+  /** Hides the "paused in debugger" overlay, if currently shown. */
+  public fun hidePausedInDebuggerOverlay()
+
   /**
    * The PackagerLocationCustomizer allows you to have a dynamic packager location that is
    * determined right before loading the packager. Your customizer must call |callback|, as loading

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactHostImpl.java

@@ -26,6 +26,7 @@
 import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.infer.annotation.ThreadConfined;
 import com.facebook.infer.annotation.ThreadSafe;
+import com.facebook.proguard.annotations.DoNotStrip;
 import com.facebook.react.JSEngineResolutionAlgorithm;
 import com.facebook.react.MemoryPressureRouter;
 import com.facebook.react.ReactHost;
@@ -466,6 +467,15 @@ public TaskInterface<Void> reload(String reason) {
         .continueWithTask(Task::getResult);
   }
 
+  @DoNotStrip
+  private void setPausedInDebuggerMessage(@Nullable String message) {
+    if (message == null) {
+      mDevSupportManager.hidePausedInDebuggerOverlay();
+    } else {
+      mDevSupportManager.showPausedInDebuggerOverlay(message);
+    }
+  }
+
   /**
    * Entrypoint to destroy the ReactInstance. If the ReactInstance is reloading, will wait until
    * reload is finished, before destroying.

packages/react-native/ReactAndroid/src/main/jni/react/jni/ReactInstanceManagerInspectorTarget.cpp

@@ -20,6 +20,14 @@ void ReactInstanceManagerInspectorTarget::TargetDelegate::onReload() const {
   method(self());
 }
 
+void ReactInstanceManagerInspectorTarget::TargetDelegate::
+    onSetPausedInDebuggerMessage(
+        const OverlaySetPausedInDebuggerMessageRequest& request) const {
+  auto method = javaClassStatic()->getMethod<void(local_ref<JString>)>(
+      "onSetPausedInDebuggerMessage");
+  method(self(), request.message ? make_jstring(*request.message) : nullptr);
+}
+
 ReactInstanceManagerInspectorTarget::ReactInstanceManagerInspectorTarget(
     jni::alias_ref<ReactInstanceManagerInspectorTarget::jhybridobject> jobj,
     jni::alias_ref<JExecutor::javaobject> executor,
@@ -82,6 +90,11 @@ void ReactInstanceManagerInspectorTarget::onReload(
   delegate_->onReload();
 }
 
+void ReactInstanceManagerInspectorTarget::onSetPausedInDebuggerMessage(
+    const OverlaySetPausedInDebuggerMessageRequest& request) {
+  delegate_->onSetPausedInDebuggerMessage(request);
+}
+
 HostTarget* ReactInstanceManagerInspectorTarget::getInspectorTarget() {
   return inspectorTarget_.get();
 }

packages/react-native/ReactAndroid/src/main/jni/react/jni/ReactInstanceManagerInspectorTarget.h

@@ -22,6 +22,8 @@ class ReactInstanceManagerInspectorTarget
         "Lcom/facebook/react/bridge/ReactInstanceManagerInspectorTarget$TargetDelegate;";
 
     void onReload() const;
+    void onSetPausedInDebuggerMessage(
+        const OverlaySetPausedInDebuggerMessageRequest& request) const;
   };
 
  public:
@@ -44,9 +46,13 @@ class ReactInstanceManagerInspectorTarget
 
   static void registerNatives();
 
-  void onReload(const PageReloadRequest& request) override;
   jsinspector_modern::HostTarget* getInspectorTarget();
 
+  // HostTargetDelegate methods
+  void onReload(const PageReloadRequest& request) override;
+  void onSetPausedInDebuggerMessage(
+      const OverlaySetPausedInDebuggerMessageRequest&) override;
+
  private:
   friend HybridBase;
 

packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactHostInspectorTarget.cpp

@@ -73,6 +73,11 @@ void JReactHostInspectorTarget::onReload(const PageReloadRequest& request) {
   javaReactHostImpl_->reload("CDP Page.reload");
 }
 
+void JReactHostInspectorTarget::onSetPausedInDebuggerMessage(
+    const OverlaySetPausedInDebuggerMessageRequest& request) {
+  javaReactHostImpl_->setPausedInDebuggerMessage(request.message);
+}
+
 HostTarget* JReactHostInspectorTarget::getInspectorTarget() {
   return inspectorTarget_ ? inspectorTarget_.get() : nullptr;
 }

packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactHostInspectorTarget.h

@@ -29,6 +29,13 @@ struct JReactHostImpl : public jni::JavaClass<JReactHostImpl> {
             "reload");
     return method(self(), reason);
   }
+
+  void setPausedInDebuggerMessage(std::optional<std::string> message) {
+    static auto method =
+        javaClassStatic()->getMethod<void(jni::local_ref<jni::JString>)>(
+            "setPausedInDebuggerMessage");
+    method(self(), message ? jni::make_jstring(*message) : nullptr);
+  }
 };
 
 class JReactHostInspectorTarget
@@ -48,6 +55,8 @@ class JReactHostInspectorTarget
   static void registerNatives();
 
   void onReload(const PageReloadRequest& request) override;
+  void onSetPausedInDebuggerMessage(
+      const OverlaySetPausedInDebuggerMessageRequest&) override;
 
   jsinspector_modern::HostTarget* getInspectorTarget();
 

packages/react-native/ReactCommon/jsinspector-modern/CdpJson.cpp

@@ -58,4 +58,15 @@ std::string jsonNotification(
   return folly::toJson(std::move(dynamicNotification));
 }
 
+std::string jsonRequest(
+    RequestId id,
+    std::string_view method,
+    std::optional<folly::dynamic> params) {
+  auto dynamicRequest = folly::dynamic::object("id", id)("method", method);
+  if (params) {
+    dynamicRequest("params", *params);
+  }
+  return folly::toJson(std::move(dynamicRequest));
+}
+
 } // namespace facebook::react::jsinspector_modern::cdp

packages/react-native/ReactCommon/jsinspector-modern/CdpJson.h

@@ -110,15 +110,29 @@ std::string jsonResult(
     const folly::dynamic& result = folly::dynamic::object());
 
 /**
- * Returns a JSON-formatted string representing a unilateral notifcation.
+ * Returns a JSON-formatted string representing a unilateral notification.
  *
  * {"method": <method>, "params": <params>}
  *
  * \param method Notification (aka "event") method.
- * \param params Optional payload pbject.
+ * \param params Optional payload object.
  */
 std::string jsonNotification(
     std::string_view method,
     std::optional<folly::dynamic> params = std::nullopt);
 
+/**
+ * Returns a JSON-formatted string representing a request.
+ *
+ * {"id": <id>, "method": <method>, "params": <params>}
+ *
+ * \param id Request ID.
+ * \param method Requested method.
+ * \param params Optional payload object.
+ */
+std::string jsonRequest(
+    RequestId id,
+    std::string_view method,
+    std::optional<folly::dynamic> params = std::nullopt);
+
 } // namespace facebook::react::jsinspector_modern::cdp

packages/react-native/ReactCommon/jsinspector-modern/HostAgent.cpp

@@ -105,6 +105,22 @@ void HostAgent::handleRequest(const cdp::PreparsedRequest& req) {
             : std::nullopt,
     });
 
+    shouldSendOKResponse = true;
+    isFinishedHandlingRequest = true;
+  } else if (req.method == "Overlay.setPausedInDebuggerMessage") {
+    auto message = req.params.isObject() && req.params.count("message")
+        ? std::optional(req.params.at("message").asString())
+        : std::nullopt;
+    if (!isPausedInDebuggerOverlayVisible_ && message.has_value()) {
+      targetController_.incrementPauseOverlayCounter();
+    } else if (isPausedInDebuggerOverlayVisible_ && !message.has_value()) {
+      targetController_.decrementPauseOverlayCounter();
+    }
+    isPausedInDebuggerOverlayVisible_ = message.has_value();
+    targetController_.getDelegate().onSetPausedInDebuggerMessage({
+        .message = message,
+    });
+
     shouldSendOKResponse = true;
     isFinishedHandlingRequest = true;
   } else if (req.method == "FuseboxClient.setClientMetadata") {
@@ -154,6 +170,20 @@ void HostAgent::handleRequest(const cdp::PreparsedRequest& req) {
       req.method + " not implemented yet"));
 }
 
+HostAgent::~HostAgent() {
+  if (isPausedInDebuggerOverlayVisible_) {
+    // In case of a non-graceful shutdown of the session, ensure we clean up
+    // the "paused on debugger" overlay if we've previously asked the
+    // integrator to display it.
+    isPausedInDebuggerOverlayVisible_ = false;
+    if (!targetController_.decrementPauseOverlayCounter()) {
+      targetController_.getDelegate().onSetPausedInDebuggerMessage({
+          .message = std::nullopt,
+      });
+    }
+  }
+}
+
 void HostAgent::sendFuseboxNotice() {
   static constexpr auto kFuseboxNotice = ANSI_COLOR_BG_YELLOW
       "Welcome to the new React Native debugger (codename " ANSI_WEIGHT_BOLD

packages/react-native/ReactCommon/jsinspector-modern/HostAgent.h

@@ -46,6 +46,13 @@ class HostAgent final {
       HostTarget::SessionMetadata sessionMetadata,
       SessionState& sessionState);
 
+  HostAgent(const HostAgent&) = delete;
+  HostAgent(HostAgent&&) = delete;
+  HostAgent& operator=(const HostAgent&) = delete;
+  HostAgent& operator=(HostAgent&&) = delete;
+
+  ~HostAgent();
+
   /**
    * Handle a CDP request. The response will be sent over the provided
    * \c FrontendChannel synchronously or asynchronously.
@@ -90,6 +97,7 @@ class HostAgent final {
   const HostTarget::SessionMetadata sessionMetadata_;
   std::shared_ptr<InstanceAgent> instanceAgent_;
   FuseboxClientType fuseboxClientType_{FuseboxClientType::Unknown};
+  bool isPausedInDebuggerOverlayVisible_{false};
 
   /**
    * A shared reference to the session's state. This is only safe to access