Add react/featureflags (facebook#52003)

Summary:
Pull Request resolved: facebook#52003

Changelog: [Internal]
This is a react common dep check that we can build and run tester.

Reviewed By: christophpurrer

Differential Revision: D76531041

fbshipit-source-id: 0a43fdb91aa61f7e6461ff8a94ea6e2732b55dbb

Author: andrewdacenko

private/react-native-fantom/tester/CMakeLists.txt

@@ -37,6 +37,7 @@ add_react_third_party_ndk_subdir(folly)
 
 # Common targets
 add_react_common_subdir(yoga)
+add_react_common_subdir(react/featureflags)
 
 file(GLOB SOURCES "src/*.cpp" "src/*.h")
 add_executable(fantom_tester ${SOURCES})
@@ -48,6 +49,7 @@ target_link_libraries(fantom_tester
     double-conversion
     fast_float
     folly_runtime
+    react_featureflags
     yogacore)
 
 target_compile_options(fantom_tester

private/react-native-fantom/tester/build.sh

@@ -15,3 +15,10 @@ cmake -S "$SCRIPT_DIR" -B "$BUILD_DIR" \
  -DREACT_COMMON_DIR="${REACT_NATIVE_ROOT_DIR}/ReactCommon"
 
 cmake --build "$BUILD_DIR" --target fantom_tester
+
+while getopts ":r" opt; do
+  case $opt in
+    r) "$BUILD_DIR/fantom_tester" ;;
+    \?) echo "Invalid option: -$OPTARG"; exit 1;;
+  esac
+done

private/react-native-fantom/tester/src/main.cpp

@@ -6,17 +6,38 @@
  */
 
 #include <glog/logging.h>
+#include <react/featureflags/ReactNativeFeatureFlags.h>
+#include <react/featureflags/ReactNativeFeatureFlagsDynamicProvider.h>
 #include <yoga/YGEnums.h>
 #include <yoga/YGValue.h>
 #include <format>
 #include <iostream>
+#include <memory>
 
-int main() {
-  google::InitGoogleLogging("fantom_tester");
+using namespace facebook::react;
+
+static void setUpLogging() {
+  google::InitGoogleLogging("react-native-fantom");
   FLAGS_logtostderr = true;
+}
 
-  LOG(INFO) << "Hello, I am fantom_tester using glog!";
+static void setUpFeatureFlags() {
+  folly::dynamic dynamicFeatureFlags = folly::dynamic::object();
+
+  dynamicFeatureFlags["enableBridgelessArchitecture"] = true;
+  dynamicFeatureFlags["cxxNativeAnimatedEnabled"] = true;
 
+  ReactNativeFeatureFlags::override(
+      std::make_unique<ReactNativeFeatureFlagsDynamicProvider>(
+          dynamicFeatureFlags));
+}
+
+int main() {
+  setUpLogging();
+
+  setUpFeatureFlags();
+
+  LOG(INFO) << "Hello, I am fantom_tester using glog!";
   LOG(INFO) << std::format(
       "[Yoga] undefined == zero: {}", YGValueZero == YGValueUndefined);