feat userver: add Serialize, Parse, and operator<< functions for proto structs

Adds

- `formats::json::Value Serialize(const TStruct& obj, formats::serialize::To<formats::json::Value>);`
- `TStruct Parse(const formats::json::Value& json, formats::parse::To<TStruct>);`
- `logging::LogHelper& operator<<(logging::LogHelper& h, const TStruct& obj);`

for easier JSON serialization, deserialization, and logging.
commit_hash:260aea1257b8d8035f17331c91a3af976647bfa3

Author: ivanlysenko

.mapping.json

@@ -3061,6 +3061,7 @@
   "libraries/proto-structs/src/proto-structs/io/userver/proto_structs/duration_conv.cpp":"taxi/uservices/userver/libraries/proto-structs/src/proto-structs/io/userver/proto_structs/duration_conv.cpp",
   "libraries/proto-structs/src/proto-structs/io/userver/proto_structs/time_of_day_conv.cpp":"taxi/uservices/userver/libraries/proto-structs/src/proto-structs/io/userver/proto_structs/time_of_day_conv.cpp",
   "libraries/proto-structs/src/proto-structs/io/userver/proto_structs/timestamp_conv.cpp":"taxi/uservices/userver/libraries/proto-structs/src/proto-structs/io/userver/proto_structs/timestamp_conv.cpp",
+  "libraries/proto-structs/src/proto-structs/json.cpp":"taxi/uservices/userver/libraries/proto-structs/src/proto-structs/json.cpp",
   "libraries/proto-structs/src/proto-structs/time_of_day.cpp":"taxi/uservices/userver/libraries/proto-structs/src/proto-structs/time_of_day.cpp",
   "libraries/proto-structs/src/proto-structs/timestamp.cpp":"taxi/uservices/userver/libraries/proto-structs/src/proto-structs/timestamp.cpp",
   "libraries/proto-structs/tests/any_test.cpp":"taxi/uservices/userver/libraries/proto-structs/tests/any_test.cpp",

libraries/proto-structs/include/userver/proto-structs/json.hpp

@@ -4,6 +4,7 @@
 /// @brief Utilities for converting protobuf structs to/from @ref formats::json::Value
 
 #include <userver/formats/json/serialize.hpp>
+#include <userver/logging/log_helper.hpp>
 #include <userver/proto-structs/convert.hpp>
 #include <userver/proto-structs/type_mapping.hpp>
 #include <userver/protobuf/json/convert.hpp>
@@ -77,4 +78,54 @@ requires traits::ProtoStruct<std::remove_cvref_t<TStruct>>
 
 }  // namespace proto_structs
 
+namespace formats::serialize {
+
+/// @brief Converts protobuf struct @a obj to @ref formats::json::Value.
+/// Conversion is performed by applying @ref proto_structs::StructToJson to @a obj
+/// with default @ref protobuf::json::PrintOptions.
+template <typename TStruct>
+requires proto_structs::traits::ProtoStruct<std::remove_cvref_t<TStruct>>
+json::Value Serialize(const TStruct& obj, To<json::Value>) {
+    return proto_structs::StructToJson(obj, {});
+}
+
+}  // namespace formats::serialize
+
+namespace formats::parse {
+
+/// @brief Converts @a json to protobuf struct of type `TStruct`.
+/// Conversion is performed by applying @ref proto_structs::JsonToStruct to @a json
+/// with default @ref protobuf::json::ParseOptions.
+template <typename TStruct>
+requires proto_structs::traits::ProtoStruct<std::remove_cvref_t<TStruct>>
+TStruct Parse(const json::Value& json, To<TStruct>) {
+    return proto_structs::JsonToStruct<TStruct>(json, {});
+}
+
+}  // namespace formats::parse
+
+namespace logging {
+
+namespace impl {
+
+logging::LogHelper& LogMessage(logging::LogHelper& h, const google::protobuf::Message& message);
+
+}  // namespace impl
+
+/// @brief Logs the protobuf struct @a obj as a JSON string.
+/// The resulting JSON is constructed with always_print_primitive_fields and preserve_proto_field_names set to true,
+/// which allows the struct field names and values to be serialized as close as possible to the definition.
+template <typename TStruct>
+requires proto_structs::traits::ProtoStruct<std::remove_cvref_t<TStruct>>
+logging::LogHelper& operator<<(logging::LogHelper& h, const TStruct& obj) {
+    try {
+        const auto message = proto_structs::StructToMessage(obj);
+        return impl::LogMessage(h, message);
+    } catch (const std::exception& ex) {
+        return h << "Failed to log struct: " << ex;
+    }
+}
+
+}  // namespace logging
+
 USERVER_NAMESPACE_END

libraries/proto-structs/src/proto-structs/json.cpp

@@ -0,0 +1,25 @@
+#include <userver/proto-structs/json.hpp>
+
+#include <google/protobuf/json/json.h>
+#include <google/protobuf/message.h>
+
+USERVER_NAMESPACE_BEGIN
+
+namespace logging::impl {
+
+logging::LogHelper& LogMessage(logging::LogHelper& h, const google::protobuf::Message& message) {
+    auto options = google::protobuf::json::PrintOptions();
+    options.always_print_primitive_fields = true;
+    options.preserve_proto_field_names = true;
+
+    TProtoStringType out;
+    const auto status = google::protobuf::json::MessageToJsonString(message, &out, options);
+    if (status.ok()) {
+        return h << out;
+    }
+    return h << "Failed to log struct: " << status;
+}
+
+}  // namespace logging::impl
+
+USERVER_NAMESPACE_END

libraries/proto-structs/tests/json_to_struct_test.cpp

@@ -10,20 +10,25 @@ USERVER_NAMESPACE_BEGIN
 
 namespace proto_structs::tests {
 
-TEST(JsonToStruct, JsonValue) {
-    messages::Scalar expected;
-    expected.set_f1(true);
-    expected.set_f2(std::numeric_limits<int32_t>::min());
-    expected.set_f3(std::numeric_limits<uint32_t>::max());
-    expected.set_f4(std::numeric_limits<int64_t>::min());
-    expected.set_f5(std::numeric_limits<uint64_t>::max());
-    expected.set_f6(static_cast<float>(1.5));
-    expected.set_f7(-2.5);
-    expected.set_f8("test1");
-    expected.set_f9("test2");
-    expected.set_f10(messages::TestEnum::TEST_ENUM_VALUE1);
-    expected.set_f11(987);
+namespace {
+
+messages::Scalar MakeMessage() {
+    messages::Scalar msg;
+    msg.set_f1(true);
+    msg.set_f2(std::numeric_limits<int32_t>::min());
+    msg.set_f3(std::numeric_limits<uint32_t>::max());
+    msg.set_f4(std::numeric_limits<int64_t>::min());
+    msg.set_f5(std::numeric_limits<uint64_t>::max());
+    msg.set_f6(static_cast<float>(1.5));
+    msg.set_f7(-2.5);
+    msg.set_f8("test1");
+    msg.set_f9("test2");
+    msg.set_f10(messages::TestEnum::TEST_ENUM_VALUE1);
+    msg.set_f11(987);
+    return msg;
+}
 
+formats::json::Value MakeJson() {
     auto builder = formats::json::ValueBuilder{formats::common::Type::kObject};
     builder["f1"] = true;
     builder["f2"] = std::numeric_limits<int32_t>::min();
@@ -37,44 +42,28 @@ TEST(JsonToStruct, JsonValue) {
     builder["f9"] = "dGVzdDI=";  // base64 encoded "test2"
     builder["f10"] = "TEST_ENUM_VALUE1";
     builder["f11"] = 987;
+    return builder.ExtractValue();
+}
+
+}  // namespace
 
+TEST(JsonToStruct, JsonValue) {
     structs::Scalar result;
-    UASSERT_NO_THROW(result = JsonToStruct<structs::Scalar>(builder.ExtractValue(), {}));
-    structs::CheckScalarEqual(result, expected);
+    UASSERT_NO_THROW(result = JsonToStruct<structs::Scalar>(MakeJson(), {}));
+    structs::CheckScalarEqual(result, MakeMessage());
 }
 
 TEST(JsonToStruct, JsonString) {
-    messages::Scalar expected;
-    expected.set_f1(true);
-    expected.set_f2(std::numeric_limits<int32_t>::min());
-    expected.set_f3(std::numeric_limits<uint32_t>::max());
-    expected.set_f4(std::numeric_limits<int64_t>::min());
-    expected.set_f5(std::numeric_limits<uint64_t>::max());
-    expected.set_f6(static_cast<float>(1.5));
-    expected.set_f7(-2.5);
-    expected.set_f8("test1");
-    expected.set_f9("test2");
-    expected.set_f10(messages::TestEnum::TEST_ENUM_VALUE1);
-    expected.set_f11(987);
-
-    auto builder = formats::json::ValueBuilder{formats::common::Type::kObject};
-    builder["f1"] = true;
-    builder["f2"] = std::numeric_limits<int32_t>::min();
-    builder["f3"] = std::numeric_limits<uint32_t>::max();
-    // 64 bits are too large for JSON numbers, so we convert to string
-    builder["f4"] = std::to_string(std::numeric_limits<int64_t>::min());
-    builder["f5"] = std::to_string(std::numeric_limits<uint64_t>::max());
-    builder["f6"] = static_cast<float>(1.5);
-    builder["f7"] = -2.5;
-    builder["f8"] = "test1";
-    builder["f9"] = "dGVzdDI=";  // base64 encoded "test2"
-    builder["f10"] = "TEST_ENUM_VALUE1";
-    builder["f11"] = 987;
-    const auto json_string = formats::json::ToString(builder.ExtractValue());
-
+    const auto json_string = formats::json::ToString(MakeJson());
     structs::Scalar result;
     UASSERT_NO_THROW(result = JsonStringToStruct<structs::Scalar>(json_string, {}));
-    structs::CheckScalarEqual(result, expected);
+    structs::CheckScalarEqual(result, MakeMessage());
+}
+
+TEST(JsonToStruct, Parse) {
+    structs::Scalar result;
+    UASSERT_NO_THROW(result = MakeJson().As<structs::Scalar>());
+    structs::CheckScalarEqual(result, MakeMessage());
 }
 
 }  // namespace proto_structs::tests

libraries/proto-structs/tests/struct_to_json_test.cpp

@@ -2,6 +2,7 @@
 
 #include <userver/proto-structs/json.hpp>
 #include <userver/utest/assert_macros.hpp>
+#include <userver/utest/log_capture_fixture.hpp>
 
 #include "messages.pb.h"
 #include "structs.hpp"
@@ -10,22 +11,10 @@ USERVER_NAMESPACE_BEGIN
 
 namespace proto_structs::tests {
 
-TEST(StructToJson, JsonValue) {
-    auto expected_builder = formats::json::ValueBuilder{formats::common::Type::kObject};
-    expected_builder["f1"] = true;
-    expected_builder["f2"] = std::numeric_limits<int32_t>::min();
-    expected_builder["f3"] = std::numeric_limits<uint32_t>::max();
-    // 64 bits are too large for JSON numbers, so we convert to string
-    expected_builder["f4"] = std::to_string(std::numeric_limits<int64_t>::min());
-    expected_builder["f5"] = std::to_string(std::numeric_limits<uint64_t>::max());
-    expected_builder["f6"] = static_cast<float>(1.5);
-    expected_builder["f7"] = -2.5;
-    expected_builder["f8"] = "test1";
-    expected_builder["f9"] = "dGVzdDI=";  // base64 encoded "test2"
-    expected_builder["f10"] = "TEST_ENUM_VALUE1";
-    expected_builder["f11"] = 987;
+namespace {
 
-    structs::Scalar obj{
+structs::Scalar MakeStruct() {
+    return structs::Scalar{
         .f1 = true,
         .f2 = std::numeric_limits<int32_t>::min(),
         .f3 = std::numeric_limits<uint32_t>::max(),
@@ -38,13 +27,9 @@ TEST(StructToJson, JsonValue) {
         .f10 = structs::TestEnum::kValue1,
         .f11 = 987
     };
-
-    formats::json::Value json;
-    UASSERT_NO_THROW(json = StructToJson(obj, {}));
-    ASSERT_EQ(json, expected_builder.ExtractValue());
 }
 
-TEST(StructToJson, JsonString) {
+formats::json::Value MakeJson() {
     auto expected_builder = formats::json::ValueBuilder{formats::common::Type::kObject};
     expected_builder["f1"] = true;
     expected_builder["f2"] = std::numeric_limits<int32_t>::min();
@@ -58,24 +43,34 @@ TEST(StructToJson, JsonString) {
     expected_builder["f9"] = "dGVzdDI=";  // base64 encoded "test2"
     expected_builder["f10"] = "TEST_ENUM_VALUE1";
     expected_builder["f11"] = 987;
+    return expected_builder.ExtractValue();
+}
 
-    structs::Scalar obj{
-        .f1 = true,
-        .f2 = std::numeric_limits<int32_t>::min(),
-        .f3 = std::numeric_limits<uint32_t>::max(),
-        .f4 = std::numeric_limits<int64_t>::min(),
-        .f5 = std::numeric_limits<uint64_t>::max(),
-        .f6 = static_cast<float>(1.5),
-        .f7 = -2.5,
-        .f8 = "test1",
-        .f9 = "test2",
-        .f10 = structs::TestEnum::kValue1,
-        .f11 = 987
-    };
+}  // namespace
+
+TEST(StructToJson, JsonValue) {
+    formats::json::Value json;
+    UASSERT_NO_THROW(json = StructToJson(MakeStruct(), {}));
+    ASSERT_EQ(json, MakeJson());
+}
 
+TEST(StructToJson, JsonString) {
     std::string json_string;
-    UASSERT_NO_THROW(json_string = StructToJsonString(obj, {}));
-    ASSERT_EQ(formats::json::FromString(json_string), expected_builder.ExtractValue());
+    UASSERT_NO_THROW(json_string = StructToJsonString(MakeStruct(), {}));
+    ASSERT_EQ(formats::json::FromString(json_string), MakeJson());
+}
+
+TEST(StructToJson, Serialize) {
+    formats::json::Value json;
+    UASSERT_NO_THROW(json = formats::json::ValueBuilder{MakeStruct()}.ExtractValue());
+    ASSERT_EQ(json, MakeJson());
+}
+
+using Logging = utest::LogCaptureFixture<>;
+
+TEST_F(Logging, LogStruct) {
+    const auto obj_string = GetLogCapture().ToStringViaLogging(MakeStruct());
+    EXPECT_EQ(obj_string, ToString(MakeJson()));
 }
 
 }  // namespace proto_structs::tests