Updated MessageToJson conversion for FieldMask in CEL C++

common/BUILD

@@ -886,6 +886,7 @@ cc_test(
         "@com_google_absl//absl/time",
         "@com_google_absl//absl/types:optional",
         "@com_google_cel_spec//proto/cel/expr/conformance/proto3:test_all_types_cc_proto",
+        "@com_google_protobuf//:field_mask_cc_proto",
         "@com_google_protobuf//:protobuf",
         "@com_google_protobuf//:struct_cc_proto",
         "@com_google_protobuf//:type_cc_proto",

common/values/parsed_message_value.cc

@@ -34,12 +34,11 @@
 #include "base/attribute.h"
 #include "common/memory.h"
 #include "common/value.h"
+#include "common/values/values.h"
 #include "extensions/protobuf/internal/qualify.h"
-#include "internal/empty_descriptors.h"
 #include "internal/json.h"
 #include "internal/message_equality.h"
 #include "internal/status_macros.h"
-#include "internal/well_known_types.h"
 #include "runtime/runtime_options.h"
 #include "google/protobuf/arena.h"
 #include "google/protobuf/descriptor.h"
@@ -51,23 +50,13 @@ namespace cel {
 
 namespace {
 
-using ::cel::well_known_types::ValueReflection;
-
 template <typename T>
 std::enable_if_t<std::is_base_of_v<google::protobuf::Message, T>,
                  const google::protobuf::Message* absl_nonnull>
 EmptyParsedMessageValue() {
   return &T::default_instance();
 }
 
-template <typename T>
-std::enable_if_t<
-    std::conjunction_v<std::is_base_of<google::protobuf::MessageLite, T>,
-                       std::negation<std::is_base_of<google::protobuf::Message, T>>>,
-    const google::protobuf::Message* absl_nonnull>
-EmptyParsedMessageValue() {
-  return internal::GetEmptyDefaultInstance();
-}
 
 }  // namespace
 
@@ -114,12 +103,8 @@ absl::Status ParsedMessageValue::ConvertToJson(
   ABSL_DCHECK_EQ(json->GetDescriptor()->well_known_type(),
                  google::protobuf::Descriptor::WELLKNOWNTYPE_VALUE);
 
-  ValueReflection value_reflection;
-  CEL_RETURN_IF_ERROR(value_reflection.Initialize(json->GetDescriptor()));
-  google::protobuf::Message* json_object = value_reflection.MutableStructValue(json);
-
   return internal::MessageToJson(*value_, descriptor_pool, message_factory,
-                                 json_object);
+                                 json);
 }
 
 absl::Status ParsedMessageValue::ConvertToJsonObject(

common/values/parsed_message_value_test.cc

@@ -14,9 +14,9 @@
 
 #include <utility>
 
+#include "google/protobuf/field_mask.pb.h"
 #include "google/protobuf/struct.pb.h"
 #include "absl/status/status_matchers.h"
-#include "absl/strings/cord.h"
 #include "absl/strings/string_view.h"
 #include "common/memory.h"
 #include "common/type.h"
@@ -74,6 +74,18 @@ TEST_F(ParsedMessageValueTest, SerializeTo) {
   EXPECT_THAT(std::move(output).Consume(), IsEmpty());
 }
 
+TEST_F(ParsedMessageValueTest, ConvertToJson_FieldMask) {
+  auto value =
+      MakeParsedMessage<google::protobuf::FieldMask>(R"pb(paths: "foo.bar"
+                                                          paths: "baz")pb");
+  auto json = DynamicParseTextProto<google::protobuf::Value>(R"pb()pb");
+  EXPECT_THAT(value.ConvertToJson(descriptor_pool(), message_factory(),
+                                  cel::to_address(json)),
+              IsOk());
+  EXPECT_THAT(*json, EqualsTextProto<google::protobuf::Value>(
+                         R"pb(string_value: "foo.bar,baz")pb"));
+}
+
 TEST_F(ParsedMessageValueTest, ConvertToJson) {
   MessageValue value = MakeParsedMessage<TestAllTypesProto3>();
   auto json = DynamicParseTextProto<google::protobuf::Value>(R"pb()pb");

conformance/BUILD

@@ -173,14 +173,9 @@ _TESTS_TO_SKIP = [
     "fields/qualified_identifier_resolution/qualified_ident,map_field_select,ident_with_longest_prefix_check,qualified_identifier_resolution_unchecked",
     "namespace/qualified/self_eval_qualified_lookup",
     "namespace/namespace/self_eval_container_lookup,self_eval_container_lookup_unchecked",
-    # TODO(issues/117): Integer overflow on enum assignments should error.
-    "enums/legacy_proto2/select_big,select_neg",
 
     # Skip until fixed.
-    "wrappers/field_mask/to_json",
-    "wrappers/empty/to_json",
     "fields/qualified_identifier_resolution/map_value_repeat_key_heterogeneous",
-    "parse/receiver_function_names",
 
     # Future features for CEL 1.0
     # TODO(issues/119): Strong typing support for enums, specified but not implemented.

eval/public/structs/BUILD

@@ -96,24 +96,22 @@ cc_test(
     ],
     deps = [
         ":cel_proto_wrap_util",
-        ":protobuf_value_factory",
         ":trivial_legacy_type_info",
         "//eval/public:cel_value",
-        "//eval/public:message_wrapper",
         "//eval/public/containers:container_backed_list_impl",
         "//eval/public/containers:container_backed_map_impl",
         "//eval/testutil:test_message_cc_proto",
         "//internal:proto_time_encoding",
-        "//internal:status_macros",
         "//internal:testing",
         "//testutil:util",
-        "@com_google_absl//absl/base:no_destructor",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/time",
+        "@com_google_absl//absl/types:span",
         "@com_google_protobuf//:any_cc_proto",
         "@com_google_protobuf//:duration_cc_proto",
         "@com_google_protobuf//:empty_cc_proto",
+        "@com_google_protobuf//:field_mask_cc_proto",
         "@com_google_protobuf//:protobuf",
         "@com_google_protobuf//:struct_cc_proto",
         "@com_google_protobuf//:wrappers_cc_proto",
@@ -218,6 +216,7 @@ cc_test(
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/time",
+        "@com_google_absl//absl/types:span",
         "@com_google_protobuf//:any_cc_proto",
         "@com_google_protobuf//:duration_cc_proto",
         "@com_google_protobuf//:empty_cc_proto",

eval/public/structs/cel_proto_wrap_util.cc

@@ -17,6 +17,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <limits>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>
@@ -50,6 +51,7 @@
 #include "internal/well_known_types.h"
 #include "google/protobuf/arena.h"
 #include "google/protobuf/descriptor.h"
+#include "google/protobuf/json/json.h"
 #include "google/protobuf/message.h"
 #include "google/protobuf/message_lite.h"
 
@@ -79,7 +81,8 @@ using google::protobuf::Descriptor;
 using google::protobuf::DescriptorPool;
 using google::protobuf::Message;
 using google::protobuf::MessageFactory;
-
+using google::protobuf::json::MessageToJsonString;
+using google::protobuf::json::PrintOptions;
 // kMaxIntJSON is defined as the Number.MAX_SAFE_INTEGER value per EcmaScript 6.
 constexpr int64_t kMaxIntJSON = (1ll << 53) - 1;
 
@@ -1079,6 +1082,38 @@ google::protobuf::Message* ValueFromValue(google::protobuf::Message* message, co
         return message;
       }
     } break;
+    case CelValue::Type::kMessage: {
+      const google::protobuf::Message* message_ptr = value.MessageOrDie();
+      if (message_ptr->GetDescriptor()->full_name() ==
+          "google.protobuf.Empty") {
+        reflection.MutableStructValue(message);
+        return message;
+      }
+      if (message_ptr->GetDescriptor()->full_name() ==
+          "google.protobuf.FieldMask") {
+        PrintOptions json_options;
+        std::string json_str;
+        auto status =
+            MessageToJsonString(*message_ptr, &json_str, json_options);
+        if (!status.ok()) {
+          return nullptr;
+        }
+        // TODO(b/540507668): Refactor to pipe descriptor_pool through
+        // ValueFromValue to use internal::MessageToJson.
+        // If JSON marshalling is correct, we know we'll always get a plain
+        // JSON string value and it shouldn't contain any escapes that we need
+        // to interpret.
+        if (json_str.size() >= 2 && json_str.front() == '"' &&
+            json_str.back() == '"') {
+          reflection.SetStringValue(message,
+                                    json_str.substr(1, json_str.size() - 2));
+        } else {
+          reflection.SetStringValue(message, json_str);
+        }
+        return message;
+      }
+      return nullptr;
+    } break;
     case CelValue::Type::kNullType:
       reflection.SetNullValue(message);
       return message;
@@ -1229,6 +1264,37 @@ bool ValueFromValue(Value* json, const CelValue& value, google::protobuf::Arena*
       return ListFromValue(json->mutable_list_value(), value, arena);
     case CelValue::Type::kMap:
       return StructFromValue(json->mutable_struct_value(), value, arena);
+    case CelValue::Type::kMessage: {
+      const google::protobuf::Message* message_ptr = value.MessageOrDie();
+      if (message_ptr->GetDescriptor()->full_name() ==
+          "google.protobuf.Empty") {
+        json->mutable_struct_value();
+        return true;
+      }
+      if (message_ptr->GetDescriptor()->full_name() ==
+          "google.protobuf.FieldMask") {
+        PrintOptions json_options;
+        std::string json_str;
+        auto status =
+            MessageToJsonString(*message_ptr, &json_str, json_options);
+        if (!status.ok()) {
+          return false;
+        }
+        // TODO(b/540507668): Refactor to pipe descriptor_pool through
+        // ValueFromValue to use internal::MessageToJson.
+        // If JSON marshalling is correct, we know we'll always get a plain
+        // JSON string value and it shouldn't contain any escapes that we need
+        // to interpret.
+        if (json_str.size() >= 2 && json_str.front() == '"' &&
+            json_str.back() == '"') {
+          json->set_string_value(json_str.substr(1, json_str.size() - 2));
+        } else {
+          json->set_string_value(json_str);
+        }
+        return true;
+      }
+      return false;
+    }
     case CelValue::Type::kNullType:
       json->set_null_value(protobuf::NULL_VALUE);
       return true;
@@ -1254,7 +1320,7 @@ google::protobuf::Message* AnyFromValue(const google::protobuf::Message* prototy
     case CelValue::Type::kBytes: {
       BytesValue v;
       type_name = v.GetTypeName();
-      v.set_value(std::string(value.BytesOrDie().value()));
+      v.set_value(value.BytesOrDie().value());
       payload = v.SerializeAsCord();
     } break;
     case CelValue::Type::kDouble: {
@@ -1280,7 +1346,7 @@ google::protobuf::Message* AnyFromValue(const google::protobuf::Message* prototy
     case CelValue::Type::kString: {
       StringValue v;
       type_name = v.GetTypeName();
-      v.set_value(std::string(value.StringOrDie().value()));
+      v.set_value(value.StringOrDie().value());
       payload = v.SerializeAsCord();
     } break;
     case CelValue::Type::kTimestamp: {