Convert iOS native module event arguments to JS without UTF-8

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

@@ -309,60 +309,106 @@ void ReactInstance::loadScript(
       });
 }
 
+namespace {
+
 /*
  * Calls a method on a JS module that has been registered with
- * `registerCallableModule`. Used to invoke a JS function from platform code.
+ * `registerCallableModule`, with the arguments that `addArgs` adds.
  */
-void ReactInstance::callFunctionOnModule(
+template <typename AddArgs>
+void callCallableModuleMethod(
+    jsi::Runtime& runtime,
+    std::unordered_map<std::string, std::variant<jsi::Function, jsi::Object>>&
+        callableModules,
     const std::string& moduleName,
     const std::string& methodName,
-    folly::dynamic&& args) {
-  bufferedRuntimeExecutor_->execute([this,
-                                     moduleName = moduleName,
-                                     methodName = methodName,
-                                     args = std::move(args)](
-                                        jsi::Runtime& runtime) {
-    TraceSection s(
-        "ReactInstance::callFunctionOnModule",
-        "moduleName",
-        moduleName,
-        "methodName",
-        methodName);
-    auto it = callableModules_.find(moduleName);
-    if (it == callableModules_.end()) {
-      std::ostringstream knownModules;
-      int i = 0;
-      for (it = callableModules_.begin(); it != callableModules_.end();
-           it++, i++) {
-        const char* space = (i > 0 ? ", " : " ");
-        knownModules << space << it->first;
-      }
-      throw jsi::JSError(
-          runtime,
-          "Failed to call into JavaScript module method " + moduleName + "." +
-              methodName +
-              "(). Module has not been registered as callable. Registered callable JavaScript modules (n = " +
-              std::to_string(callableModules_.size()) +
-              "):" + knownModules.str() +
-              ". Did you forget to call `registerCallableModule`?");
+    const AddArgs& addArgs) {
+  TraceSection s(
+      "ReactInstance::callFunctionOnModule",
+      "moduleName",
+      moduleName,
+      "methodName",
+      methodName);
+  auto it = callableModules.find(moduleName);
+  if (it == callableModules.end()) {
+    std::ostringstream knownModules;
+    int i = 0;
+    for (it = callableModules.begin(); it != callableModules.end(); it++, i++) {
+      const char* space = (i > 0 ? ", " : " ");
+      knownModules << space << it->first;
     }
+    throw jsi::JSError(
+        runtime,
+        "Failed to call into JavaScript module method " + moduleName + "." +
+            methodName +
+            "(). Module has not been registered as callable. Registered callable JavaScript modules (n = " +
+            std::to_string(callableModules.size()) + "):" + knownModules.str() +
+            ". Did you forget to call `registerCallableModule`?");
+  }
 
-    if (std::holds_alternative<jsi::Function>(it->second)) {
-      auto module =
-          std::get<jsi::Function>(it->second).call(runtime).asObject(runtime);
-      it->second = std::move(module);
-    }
+  if (std::holds_alternative<jsi::Function>(it->second)) {
+    auto module =
+        std::get<jsi::Function>(it->second).call(runtime).asObject(runtime);
+    it->second = std::move(module);
+  }
 
-    auto& module = std::get<jsi::Object>(it->second);
-    auto method = module.getPropertyAsFunction(runtime, methodName.c_str());
+  auto& module = std::get<jsi::Object>(it->second);
+  auto method = module.getPropertyAsFunction(runtime, methodName.c_str());
 
-    std::vector<jsi::Value> jsArgs;
-    for (auto& arg : args) {
-      jsArgs.push_back(jsi::valueFromDynamic(runtime, arg));
-    }
-    method.callWithThis(
-        runtime, module, (const jsi::Value*)jsArgs.data(), jsArgs.size());
-  });
+  std::vector<jsi::Value> jsArgs;
+  addArgs(jsArgs);
+  method.callWithThis(
+      runtime, module, (const jsi::Value*)jsArgs.data(), jsArgs.size());
+}
+
+} // namespace
+
+/*
+ * Calls a method on a JS module that has been registered with
+ * `registerCallableModule`. Used to invoke a JS function from platform code.
+ */
+void ReactInstance::callFunctionOnModule(
+    const std::string& moduleName,
+    const std::string& methodName,
+    folly::dynamic&& args) {
+  bufferedRuntimeExecutor_->execute(
+      [this,
+       moduleName = moduleName,
+       methodName = methodName,
+       args = std::move(args)](jsi::Runtime& runtime) {
+        callCallableModuleMethod(
+            runtime,
+            callableModules_,
+            moduleName,
+            methodName,
+            [&](std::vector<jsi::Value>& jsArgs) {
+              for (auto& arg : args) {
+                jsArgs.push_back(jsi::valueFromDynamic(runtime, arg));
+              }
+            });
+      });
+}
+
+void ReactInstance::callFunctionOnModule(
+    const std::string& moduleName,
+    const std::string& methodName,
+    ArgFactory&& argFactory) {
+  bufferedRuntimeExecutor_->execute(
+      [this,
+       moduleName = moduleName,
+       methodName = methodName,
+       argFactory = std::move(argFactory)](jsi::Runtime& runtime) {
+        callCallableModuleMethod(
+            runtime,
+            callableModules_,
+            moduleName,
+            methodName,
+            [&](std::vector<jsi::Value>& jsArgs) {
+              if (argFactory) {
+                argFactory(runtime, jsArgs);
+              }
+            });
+      });
 }
 
 void ReactInstance::registerSegment(

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

@@ -27,6 +27,7 @@ namespace facebook::react {
 class ReactInstance final : private jsinspector_modern::InstanceTargetDelegate {
  public:
   using BindingsInstallFunc = std::function<void(jsi::Runtime &runtime)>;
+  using ArgFactory = std::function<void(jsi::Runtime &runtime, std::vector<jsi::Value> &args)>;
 
   ReactInstance(
       std::unique_ptr<JSRuntime> runtime,
@@ -71,6 +72,12 @@ class ReactInstance final : private jsinspector_modern::InstanceTargetDelegate {
 
   void callFunctionOnModule(const std::string &moduleName, const std::string &methodName, folly::dynamic &&args);
 
+  /**
+   * Like the overload above, but `argFactory` adds the arguments on the JS thread, so platform
+   * values can be converted to JS values directly.
+   */
+  void callFunctionOnModule(const std::string &moduleName, const std::string &methodName, ArgFactory &&argFactory);
+
   void handleMemoryPressureJs(int pressureLevel);
 
   /**