react-native code-gen > Add a C++ only TurboModule example (for Android/iOS/macOS/Windows) (#35138)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/35138

Changelog:

[General][Added] - Add a C++ only TurboModule example (for Android/iOS/macOS/Windows)

react-native@0.69 introduced a new bridging layer to ease integration for pure C++ TurboModules using C++ std:: types directly instead of the lower level jsi:: types:
https://github.com/facebook/react-native/tree/v0.69.0/ReactCommon/react/bridging

This bridging layer can be used in JSI functions or more conveniently in C++ TurboModules.

Here is a example of an C++ only TurboModule which will work on Android and iOS and macOS/Windows (using microsoft/react-native-macos|windows) only using flow/TypeScript and standard C++ types.

C++ only TurboModules are very handy as they do not require to work with JSI APIs - instead std:: or custom C++ can by used.

Reviewed By: javache

Differential Revision: D39011736

fbshipit-source-id: 84c833d8540671fde8505f1aeb0265074b248730

packages/rn-tester/NativeCxxModuleExample/NativeCxxModuleExample.cpp

@@ -0,0 +1,110 @@
+/*
+ * 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 "NativeCxxModuleExample.h"
+
+namespace facebook::react {
+
+NativeCxxModuleExample::NativeCxxModuleExample(
+    std::shared_ptr<CallInvoker> jsInvoker)
+    : NativeCxxModuleExampleCxxSpec(std::move(jsInvoker)) {}
+
+void NativeCxxModuleExample::getValueWithCallback(
+    jsi::Runtime &rt,
+    AsyncCallback<std::string> callback) {
+  callback({"value from callback!"});
+}
+
+std::vector<std::optional<ObjectStruct>> NativeCxxModuleExample::getArray(
+    jsi::Runtime &rt,
+    std::vector<std::optional<ObjectStruct>> arg) {
+  return arg;
+}
+
+bool NativeCxxModuleExample::getBool(jsi::Runtime &rt, bool arg) {
+  return arg;
+}
+
+ConstantsStruct NativeCxxModuleExample::getConstants(jsi::Runtime &rt) {
+  return ConstantsStruct{true, 69, "react-native"};
+}
+
+int32_t NativeCxxModuleExample::getEnum(jsi::Runtime &rt, int32_t arg) {
+  return arg;
+}
+
+std::map<std::string, std::optional<int32_t>> NativeCxxModuleExample::getMap(
+    jsi::Runtime &rt,
+    std::map<std::string, std::optional<int32_t>> arg) {
+  return arg;
+}
+
+double NativeCxxModuleExample::getNumber(jsi::Runtime &rt, double arg) {
+  return arg;
+}
+
+ObjectStruct NativeCxxModuleExample::getObject(
+    jsi::Runtime &rt,
+    ObjectStruct arg) {
+  return arg;
+}
+
+std::set<float> NativeCxxModuleExample::getSet(
+    jsi::Runtime &rt,
+    std::set<float> arg) {
+  return arg;
+}
+
+std::string NativeCxxModuleExample::getString(
+    jsi::Runtime &rt,
+    std::string arg) {
+  return arg;
+}
+
+std::string NativeCxxModuleExample::getUnion(
+    jsi::Runtime &rt,
+    float x,
+    std::string y,
+    jsi::Object z) {
+  std::string result = "x: " + std::to_string(x) + ", y: " + y + ", z: { ";
+  if (z.hasProperty(rt, "value")) {
+    result += "value: ";
+    result += std::to_string(z.getProperty(rt, "value").getNumber());
+  } else if (z.hasProperty(rt, "low")) {
+    result += "low: ";
+    result += z.getProperty(rt, "low").getString(rt).utf8(rt);
+  }
+  result += " }";
+  return result;
+}
+
+ValueStruct NativeCxxModuleExample::getValue(
+    jsi::Runtime &rt,
+    double x,
+    std::string y,
+    ObjectStruct z) {
+  ValueStruct result{x, y, z};
+  return result;
+}
+
+AsyncPromise<std::string> NativeCxxModuleExample::getValueWithPromise(
+    jsi::Runtime &rt,
+    bool error) {
+  auto promise = AsyncPromise<std::string>(rt, jsInvoker_);
+  if (error) {
+    promise.reject("intentional promise rejection");
+  } else {
+    promise.resolve("result!");
+  }
+  return promise;
+}
+
+void NativeCxxModuleExample::voidFunc(jsi::Runtime &rt) {
+  // Nothing to do
+}
+
+} // namespace facebook::react