Extract shared GlobalStateObserver from FuseboxSessionObserver

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

@@ -8,6 +8,7 @@
 #include "SessionState.h"
 
 #include <jsinspector-modern/RuntimeTarget.h>
+#include <jsinspector-modern/RuntimeTargetGlobalStateObserver.h>
 #include <jsinspector-modern/tracing/PerformanceTracer.h>
 
 #include <utility>
@@ -16,21 +17,6 @@ using namespace facebook::jsi;
 
 namespace facebook::react::jsinspector_modern {
 
-namespace {
-
-void emitSessionStatusChangeForObserverWithValue(
-    jsi::Runtime& runtime,
-    const jsi::Value& value) {
-  auto globalObj = runtime.global();
-  auto observer =
-      globalObj.getPropertyAsObject(runtime, "__DEBUGGER_SESSION_OBSERVER__");
-  auto onSessionStatusChange =
-      observer.getPropertyAsFunction(runtime, "onSessionStatusChange");
-  onSessionStatusChange.call(runtime, value);
-}
-
-} // namespace
-
 std::shared_ptr<RuntimeTarget> RuntimeTarget::create(
     const ExecutionContextDescription& executionContextDescription,
     RuntimeTargetDelegate& delegate,
@@ -144,7 +130,11 @@ void RuntimeTarget::installBindingHandler(const std::string& bindingName) {
 void RuntimeTarget::emitDebuggerSessionCreated() {
   jsExecutor_([selfExecutor = executorFromThis()](jsi::Runtime& runtime) {
     try {
-      emitSessionStatusChangeForObserverWithValue(runtime, jsi::Value(true));
+      emitGlobalStateObserverChange(
+          runtime,
+          "__DEBUGGER_SESSION_OBSERVER__",
+          "onSessionStatusChange",
+          true);
     } catch (jsi::JSError&) {
       // Suppress any errors, they should not be visible to the user
       // and should not affect runtime.
@@ -155,7 +145,11 @@ void RuntimeTarget::emitDebuggerSessionCreated() {
 void RuntimeTarget::emitDebuggerSessionDestroyed() {
   jsExecutor_([selfExecutor = executorFromThis()](jsi::Runtime& runtime) {
     try {
-      emitSessionStatusChangeForObserverWithValue(runtime, jsi::Value(false));
+      emitGlobalStateObserverChange(
+          runtime,
+          "__DEBUGGER_SESSION_OBSERVER__",
+          "onSessionStatusChange",
+          false);
     } catch (jsi::JSError&) {
       // Suppress any errors, they should not be visible to the user
       // and should not affect runtime.

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

@@ -6,106 +6,17 @@
  */
 
 #include <jsinspector-modern/RuntimeTarget.h>
+#include <jsinspector-modern/RuntimeTargetGlobalStateObserver.h>
 
 namespace facebook::react::jsinspector_modern {
 
 void RuntimeTarget::installDebuggerSessionObserver() {
   jsExecutor_([](jsi::Runtime& runtime) {
-    auto globalObj = runtime.global();
-    try {
-      auto observer = jsi::Object(runtime);
-
-      observer.setProperty(runtime, "hasActiveSession", jsi::Value(false));
-
-      auto setFunction = globalObj.getPropertyAsFunction(runtime, "Set");
-      auto set = setFunction.callAsConstructor(runtime);
-      observer.setProperty(runtime, "subscribers", set);
-
-      observer.setProperty(
-          runtime,
-          "onSessionStatusChange",
-          jsi::Function::createFromHostFunction(
-              runtime,
-              jsi::PropNameID::forAscii(runtime, "onSessionStatusChange"),
-              1,
-              [](jsi::Runtime& onSessionStatusChangeRuntime,
-                 const jsi::Value& /* onSessionStatusChangeThisVal */,
-                 const jsi::Value* onSessionStatusChangeArgs,
-                 size_t onSessionStatusChangeArgsCount) {
-                if (onSessionStatusChangeArgsCount != 1 ||
-                    !onSessionStatusChangeArgs[0].isBool()) {
-                  throw jsi::JSError(
-                      onSessionStatusChangeRuntime,
-                      "Invalid arguments: onSessionStatusChange expects 1 boolean argument");
-                }
-
-                bool updatedStatus = onSessionStatusChangeArgs[0].getBool();
-
-                auto observerInstanceFromOnSessionStatusChange =
-                    onSessionStatusChangeRuntime.global().getPropertyAsObject(
-                        onSessionStatusChangeRuntime,
-                        "__DEBUGGER_SESSION_OBSERVER__");
-                auto subscribersToNotify =
-                    observerInstanceFromOnSessionStatusChange
-                        .getPropertyAsObject(
-                            onSessionStatusChangeRuntime, "subscribers");
-
-                observerInstanceFromOnSessionStatusChange.setProperty(
-                    onSessionStatusChangeRuntime,
-                    "hasActiveSession",
-                    updatedStatus);
-
-                if (subscribersToNotify
-                        .getProperty(onSessionStatusChangeRuntime, "size")
-                        .asNumber() == 0) {
-                  return jsi::Value::undefined();
-                }
-
-                auto forEachSubscriber =
-                    subscribersToNotify.getPropertyAsFunction(
-                        onSessionStatusChangeRuntime, "forEach");
-                auto forEachSubscriberCallback =
-                    jsi::Function::createFromHostFunction(
-                        onSessionStatusChangeRuntime,
-                        jsi::PropNameID::forAscii(
-                            onSessionStatusChangeRuntime, "forEachCallback"),
-                        1,
-                        [updatedStatus](
-                            jsi::Runtime& forEachCallbackRuntime,
-                            const jsi::Value& /* forEachCallbackThisVal */,
-                            const jsi::Value* forEachCallbackArgs,
-                            size_t forEachCallbackArgsCount) {
-                          if (forEachCallbackArgsCount < 1 ||
-                              !forEachCallbackArgs[0].isObject() ||
-                              !forEachCallbackArgs[0]
-                                   .getObject(forEachCallbackRuntime)
-                                   .isFunction(forEachCallbackRuntime)) {
-                            throw jsi::JSError(
-                                forEachCallbackRuntime,
-                                "Invalid arguments: forEachSubscriberCallback expects function as a first argument");
-                          }
-
-                          forEachCallbackArgs[0]
-                              .getObject(forEachCallbackRuntime)
-                              .asFunction(forEachCallbackRuntime)
-                              .call(forEachCallbackRuntime, updatedStatus);
-
-                          return jsi::Value::undefined();
-                        });
-
-                forEachSubscriber.callWithThis(
-                    onSessionStatusChangeRuntime,
-                    subscribersToNotify,
-                    forEachSubscriberCallback);
-
-                return jsi::Value::undefined();
-              }));
-
-      globalObj.setProperty(runtime, "__DEBUGGER_SESSION_OBSERVER__", observer);
-    } catch (jsi::JSError&) {
-      // Suppress any errors, they should not be visible to the user
-      // and should not affect runtime.
-    }
+    installGlobalStateObserver(
+        runtime,
+        "__DEBUGGER_SESSION_OBSERVER__",
+        "hasActiveSession",
+        "onSessionStatusChange");
   });
 }
 

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

@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "RuntimeTargetGlobalStateObserver.h"
+
+#include <string>
+
+namespace facebook::react::jsinspector_modern {
+
+void installGlobalStateObserver(
+    jsi::Runtime& runtime,
+    const char* globalName,
+    const char* statusProperty,
+    const char* callbackName) {
+  auto globalObj = runtime.global();
+  try {
+    auto observer = jsi::Object(runtime);
+
+    observer.setProperty(runtime, statusProperty, jsi::Value(false));
+
+    auto setFunction = globalObj.getPropertyAsFunction(runtime, "Set");
+    auto set = setFunction.callAsConstructor(runtime);
+    observer.setProperty(runtime, "subscribers", set);
+
+    std::string globalNameStr(globalName);
+    std::string statusPropertyStr(statusProperty);
+
+    observer.setProperty(
+        runtime,
+        callbackName,
+        jsi::Function::createFromHostFunction(
+            runtime,
+            jsi::PropNameID::forAscii(runtime, callbackName),
+            1,
+            [globalNameStr, statusPropertyStr](
+                jsi::Runtime& callbackRuntime,
+                const jsi::Value& /* thisVal */,
+                const jsi::Value* args,
+                size_t argsCount) {
+              if (argsCount != 1 || !args[0].isBool()) {
+                throw jsi::JSError(
+                    callbackRuntime,
+                    "Invalid arguments: state change callback expects 1 boolean argument");
+              }
+
+              bool updatedStatus = args[0].getBool();
+
+              auto observerInstance =
+                  callbackRuntime.global().getPropertyAsObject(
+                      callbackRuntime, globalNameStr.c_str());
+              auto subscribersToNotify = observerInstance.getPropertyAsObject(
+                  callbackRuntime, "subscribers");
+
+              observerInstance.setProperty(
+                  callbackRuntime, statusPropertyStr.c_str(), updatedStatus);
+
+              if (subscribersToNotify.getProperty(callbackRuntime, "size")
+                      .asNumber() == 0) {
+                return jsi::Value::undefined();
+              }
+
+              auto forEachSubscriber =
+                  subscribersToNotify.getPropertyAsFunction(
+                      callbackRuntime, "forEach");
+              auto forEachSubscriberCallback = jsi::Function::createFromHostFunction(
+                  callbackRuntime,
+                  jsi::PropNameID::forAscii(callbackRuntime, "forEachCallback"),
+                  1,
+                  [updatedStatus](
+                      jsi::Runtime& forEachCallbackRuntime,
+                      const jsi::Value& /* forEachCallbackThisVal */,
+                      const jsi::Value* forEachCallbackArgs,
+                      size_t forEachCallbackArgsCount) {
+                    if (forEachCallbackArgsCount < 1 ||
+                        !forEachCallbackArgs[0].isObject() ||
+                        !forEachCallbackArgs[0]
+                             .getObject(forEachCallbackRuntime)
+                             .isFunction(forEachCallbackRuntime)) {
+                      throw jsi::JSError(
+                          forEachCallbackRuntime,
+                          "Invalid arguments: forEachSubscriberCallback expects function as a first argument");
+                    }
+
+                    forEachCallbackArgs[0]
+                        .getObject(forEachCallbackRuntime)
+                        .asFunction(forEachCallbackRuntime)
+                        .call(forEachCallbackRuntime, updatedStatus);
+
+                    return jsi::Value::undefined();
+                  });
+
+              forEachSubscriber.callWithThis(
+                  callbackRuntime,
+                  subscribersToNotify,
+                  forEachSubscriberCallback);
+
+              return jsi::Value::undefined();
+            }));
+
+    globalObj.setProperty(runtime, globalName, observer);
+  } catch (jsi::JSError&) {
+    // Suppress any errors, they should not be visible to the user
+    // and should not affect runtime.
+  }
+}
+
+void emitGlobalStateObserverChange(
+    jsi::Runtime& runtime,
+    const char* globalName,
+    const char* callbackName,
+    bool value) {
+  auto globalObj = runtime.global();
+  auto observer = globalObj.getPropertyAsObject(runtime, globalName);
+  auto callback = observer.getPropertyAsFunction(runtime, callbackName);
+  callback.call(runtime, jsi::Value(value));
+}
+
+} // namespace facebook::react::jsinspector_modern

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

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <jsi/jsi.h>
+
+namespace facebook::react::jsinspector_modern {
+
+/**
+ * Installs a global state observer object on the JavaScript runtime's global
+ * object. The observer has a boolean status property, a Set of subscribers,
+ * and a callback that updates the status and notifies subscribers.
+ *
+ * @param globalName The name of the global object (e.g.,
+ *   "__DEBUGGER_SESSION_OBSERVER__").
+ * @param statusProperty The name of the boolean property (e.g.,
+ *   "hasActiveSession").
+ * @param callbackName The name of the state change callback (e.g.,
+ *   "onSessionStatusChange").
+ */
+void installGlobalStateObserver(
+    jsi::Runtime &runtime,
+    const char *globalName,
+    const char *statusProperty,
+    const char *callbackName);
+
+/**
+ * Emits a state change to an installed global state observer by calling its
+ * callback function.
+ *
+ * @param globalName The name of the global object.
+ * @param callbackName The name of the state change callback.
+ * @param value The new boolean state value.
+ */
+void emitGlobalStateObserverChange(jsi::Runtime &runtime, const char *globalName, const char *callbackName, bool value);
+
+} // namespace facebook::react::jsinspector_modern

packages/react-native/src/private/devsupport/rndevtools/FuseboxSessionObserver.js

@@ -8,34 +8,21 @@
  * @format
  */
 
-class FuseboxSessionObserver {
-  #hasNativeSupport: boolean;
+import GlobalStateObserver from './GlobalStateObserver';
 
-  constructor() {
-    this.#hasNativeSupport = global.hasOwnProperty(
-      '__DEBUGGER_SESSION_OBSERVER__',
-    );
-  }
+const observer = new GlobalStateObserver(
+  '__DEBUGGER_SESSION_OBSERVER__',
+  'hasActiveSession',
+);
 
+const FuseboxSessionObserver = {
   hasActiveSession(): boolean {
-    if (!this.#hasNativeSupport) {
-      return false;
-    }
-
-    return global.__DEBUGGER_SESSION_OBSERVER__.hasActiveSession;
-  }
+    return observer.getStatus();
+  },
 
   subscribe(callback: (status: boolean) => void): () => void {
-    if (!this.#hasNativeSupport) {
-      return () => {};
-    }
-
-    global.__DEBUGGER_SESSION_OBSERVER__.subscribers.add(callback);
-    return () => {
-      global.__DEBUGGER_SESSION_OBSERVER__.subscribers.delete(callback);
-    };
-  }
-}
+    return observer.subscribe(callback);
+  },
+};
 
-const observerInstance: FuseboxSessionObserver = new FuseboxSessionObserver();
-export default observerInstance;
+export default FuseboxSessionObserver;