Fabric: Fixed parsing of `backfaceVisibility` prop

Summary: I have noticed that `backfaceVisibility` example crashes (because actual value is a string/enum, not a boolean), so I fixed it.

Reviewed By: JoshuaGross, mdvacca

Differential Revision: D15219261

fbshipit-source-id: 27f76cd10903794d597adacb9da7300a42813f8e

React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm

@@ -159,7 +159,7 @@ using namespace facebook::react;
 
   // `backfaceVisibility`
   if (oldViewProps.backfaceVisibility != newViewProps.backfaceVisibility) {
-    self.layer.doubleSided = newViewProps.backfaceVisibility;
+    self.layer.doubleSided = newViewProps.backfaceVisibility == BackfaceVisibility::Visible;
   }
 
   // `shouldRasterize`

ReactCommon/fabric/components/view/ViewProps.h

@@ -51,7 +51,7 @@ class ViewProps : public Props,
 
   // Transform
   Transform transform{};
-  bool const backfaceVisibility{};
+  BackfaceVisibility const backfaceVisibility{};
   bool const shouldRasterize{};
   int const zIndex{};
 

ReactCommon/fabric/components/view/conversions.h

@@ -475,6 +475,24 @@ inline void fromRawValue(const RawValue &value, PointerEventsMode &result) {
   LOG(FATAL) << "Could not parse PointerEventsMode:" << stringValue;
 }
 
+inline void fromRawValue(const RawValue &value, BackfaceVisibility &result) {
+  assert(value.hasType<std::string>());
+  auto stringValue = (std::string)value;
+  if (stringValue == "auto") {
+    result = BackfaceVisibility::Auto;
+    return;
+  }
+  if (stringValue == "visible") {
+    result = BackfaceVisibility::Visible;
+    return;
+  }
+  if (stringValue == "hidden") {
+    result = BackfaceVisibility::Hidden;
+    return;
+  }
+  LOG(FATAL) << "Could not parse BackfaceVisibility:" << stringValue;
+}
+
 inline void fromRawValue(const RawValue &value, BorderStyle &result) {
   assert(value.hasType<std::string>());
   auto stringValue = (std::string)value;

ReactCommon/fabric/components/view/primitives.h

@@ -18,6 +18,8 @@ namespace react {
 
 enum class PointerEventsMode { Auto, None, BoxNone, BoxOnly };
 
+enum class BackfaceVisibility { Auto, Visible, Hidden };
+
 enum class BorderStyle { Solid, Dotted, Dashed };
 
 template <typename T>