Feature: iq::Roster

Reviewed-on: http://ivt5wiimhwpo56td6eodn2n3fduug3bglqvqewbk2jnyl4hcimea.b32.i2p/git/git/Larra/larra/pulls/2

.devcontainer/Dockerfile

@@ -37,25 +37,24 @@ ADD https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VER}/L
 
 # Create the LLVM directory and extract only binaries into it
 RUN sudo mkdir -p /home/LLVM-${LLVM_VER}
-RUN sudo tar -xJf /home/artifacts/LLVM-${LLVM_VER}-Linux-X64.tar.xz -C /home/LLVM-${LLVM_VER} --strip-components=1
-#RUN sudo tar -xJf /home/artifacts/LLVM-${LLVM_VER}-Linux-X64.tar.xz -C /home/LLVM-${LLVM_VER} --strip-components=1 \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clangd                   \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang-19                 \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang                    \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang++                  \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/lld                      \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/ld.lld                   \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/ld64.lld                 \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang-scan-deps          \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/llvm-symbolizer          \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang-format             \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang-tidy               \
-#    LLVM-${LLVM_VER}-Linux-X64/bin/clang-apply-replacements \
-#    LLVM-${LLVM_VER}-Linux-X64/include/                     \
-#    LLVM-${LLVM_VER}-Linux-X64/lib/                         \
-#    LLVM-${LLVM_VER}-Linux-X64/libexec/                     \
-#    LLVM-${LLVM_VER}-Linux-X64/local/                       \
-#    LLVM-${LLVM_VER}-Linux-X64/share/
+RUN sudo tar -xJf /home/artifacts/LLVM-${LLVM_VER}-Linux-X64.tar.xz -C /home/LLVM-${LLVM_VER} --strip-components=1 \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clangd                   \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang-19                 \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang                    \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang++                  \
+    LLVM-${LLVM_VER}-Linux-X64/bin/lld                      \
+    LLVM-${LLVM_VER}-Linux-X64/bin/ld.lld                   \
+    LLVM-${LLVM_VER}-Linux-X64/bin/ld64.lld                 \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang-scan-deps          \
+    LLVM-${LLVM_VER}-Linux-X64/bin/llvm-symbolizer          \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang-format             \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang-tidy               \
+    LLVM-${LLVM_VER}-Linux-X64/bin/clang-apply-replacements \
+    LLVM-${LLVM_VER}-Linux-X64/include/                     \
+    LLVM-${LLVM_VER}-Linux-X64/lib/                         \
+    LLVM-${LLVM_VER}-Linux-X64/libexec/                     \
+    LLVM-${LLVM_VER}-Linux-X64/local/                       \
+    LLVM-${LLVM_VER}-Linux-X64/share/
 
 # Add /home/LLVM-${LLVM_VER}/bin to the PATH environment variable
 ENV PATH="/home/LLVM-${LLVM_VER}/bin:${PATH}"

.forgejo/workflows/pr_check.yaml

@@ -11,11 +11,11 @@ jobs:
           pacman -Syyu --noconfirm
           pacman -S --noconfirm git less vim sudo python-pip wget which pkgconf nodejs-lts-iron
           pacman -S --noconfirm cmake make gcc ninja meson
-          pacman -S --noconfirm gtk4 gtkmm-4.0 boost spdlog fmt libxml++-5.0
+          pacman -S --noconfirm gtk4 gtkmm-4.0 boost spdlog fmt libxml++-5.0 gtest
 
-      - name: Setup environment - Install LLVM-19.1.1
+      - name: Setup environment - Install LLVM-19.1.3
         run: |
-          export LLVM_VER=19.1.1
+          export LLVM_VER=19.1.3
 
           echo "::group::Download LLVM-${LLVM_VER}"
           wget https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VER}/LLVM-${LLVM_VER}-Linux-X64.tar.xz -O /LLVM-${LLVM_VER}-Linux-X64.tar.xz
@@ -105,8 +105,10 @@ jobs:
       #    key: LLVM-${LLVM_VER}-Linux-X64-small
 
       - name: Check clang-format
+        id: clang_format_check
+        continue-on-error: true
         run: |
-          export LLVM_VER=19.1.1
+          export LLVM_VER=19.1.3
           export PATH="/home/LLVM-${LLVM_VER}/bin:${PATH}"
           cd ${{ github.workspace }}
           export REPO_FILES=$(cat repo_files_to_check.txt)
@@ -120,6 +122,8 @@ jobs:
           echo "No clang-format violations detected!"
 
       - name: GCC build
+        id: gcc_build
+        continue-on-error: true
         run: |
           mkdir -p ${{ github.workspace }}/build_gcc
           cmake -Wno-dev \
@@ -129,32 +133,56 @@ jobs:
             -B ${{ github.workspace }}/build_gcc \
             -GNinja -DCMAKE_BUILD_TYPE=Release   \
             -DENABLE_EXAMPLES=ON                 \
-            -DENABLE_TESTS=ON
+            -DENABLE_TESTS=ON                    \
+            -DCMAKE_CXX_FLAGS="-ftemplate-backtrace-limit=0"
           cmake --build ${{ github.workspace }}/build_gcc --parallel `nproc`
 
       - name: GCC unit tests
+        id: gcc_unit_tests
+        continue-on-error: true
         run: |
           cd ${{ github.workspace }}/build_gcc
           ./larra_xmpp_tests
 
-      - name: Check clang-tidy
+      - name: Clang build (only configuring)
+        id: clang_build
+        continue-on-error: true
         run: |
-          export LLVM_VER=19.1.1
+          export LLVM_VER=19.1.3
+          export PATH="/home/LLVM-${LLVM_VER}/bin:${PATH}"
+          mkdir -p ${{ github.workspace }}/build_clang
+
+          cmake -Wno-dev                           \
+            -DCMAKE_C_COMPILER=clang               \
+            -DCMAKE_CXX_COMPILER=clang++           \
+            -S ${{ github.workspace }}             \
+            -B ${{ github.workspace }}/build_clang \
+            -GNinja -DCMAKE_BUILD_TYPE=Release     \
+            -DENABLE_EXAMPLES=ON                   \
+            -DENABLE_TESTS=ON                      \
+            -DCMAKE_CXX_FLAGS="-stdlib=libc++ -I/home/LLVM-${LLVM_VER}/include/c++/v1 -fno-modules"
+
+          echo "::group::compile_commands.json content"
+          cat ${{ github.workspace }}/build_clang/compile_commands.json
+          echo "::endgroup::"
+
+          sed -i 's|@.*\.modmap||' ${{ github.workspace }}/build_clang/compile_commands.json
+
+      - name: Check clang-tidy
+        id: clang_tidy
+        continue-on-error: true
+        run: |
+          export LLVM_VER=19.1.3
           export PATH="/home/LLVM-${LLVM_VER}/bin:${PATH}"
           cd ${{ github.workspace }}
 
-          sed -i 's|/usr/sbin/g++|/home/LLVM-19.1.1/bin/clang++ -stdlib=libc++ -I/home/LLVM-${LLVM_VER}/include/c++/v1|' build_gcc/compile_commands.json
-          sed -i 's|-fdeps-format=p1689r5||' build_gcc/compile_commands.json
-          sed -i 's|-fmodules-ts||' build_gcc/compile_commands.json
-          sed -i 's|-fmodule-mapper=.*\.modmap||' build_gcc/compile_commands.json
-
           wget https://raw.githubusercontent.com/llvm/llvm-project/refs/heads/main/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
           python run-clang-tidy.py                           \
             -warnings-as-errors=*                            \
             -use-color                                       \
             -exclude-header-filter .*build.*                 \
             -header-filter .hpp                              \
-            -p ${{ github.workspace }}/build_gcc/            \
+            -p ${{ github.workspace }}/build_clang/          \
             -config-file ${{ github.workspace }}/.clang-tidy \
             \
             ${{ github.workspace }}/examples \
@@ -163,26 +191,13 @@ jobs:
 
           echo "No clang-tidy violations detected!"
 
-      #- name: Clang build with -fsanitize=address
-      #  run: |
-      #    export LLVM_VER=19.1.1
-      #    export PATH="/home/LLVM-${LLVM_VER}/bin:${PATH}"
-      #    mkdir -p ${{ github.workspace }}/build_clang
-      #    cmake -Wno-dev                           \
-      #      -DCMAKE_C_COMPILER=clang               \
-      #      -DCMAKE_CXX_COMPILER=clang++           \
-      #      -S ${{ github.workspace }}             \
-      #      -B ${{ github.workspace }}/build_clang \
-      #      -GNinja -DCMAKE_BUILD_TYPE=Release     \
-      #      -DENABLE_EXAMPLES=ON                   \
-      #      -DENABLE_TESTS=ON                      \
-      #      -DCMAKE_CXX_FLAGS="-stdlib=libc++ -I/home/LLVM-${LLVM_VER}/include/c++/v1 -fno-omit-frame-pointer -g -fsanitize=address,undefined,leak,function,nullability,vptr" \
-      #      -DCMAKE_EXE_LINKER_FLAGS="-L/home/LLVM-${LLVM_VER}/lib/ -Wl,-rpath,/home/LLVM-${LLVM_VER}/lib -lc++ -lc++abi -lm -lc -lgcc_s -lgcc -fno-omit-frame-pointer -g  -fsanitize=address,undefined,leak,function,nullability,vptr"
-      #    cmake --build ${{ github.workspace }}/build_clang --parallel `nproc`
+      - name: Check on failures
+        if: steps.clang_format_check.outcome != 'success' || steps.gcc_build.outcome != 'success' || steps.gcc_unit_tests.outcome != 'success' || steps.clang_build.outcome != 'success' || steps.clang_tidy.outcome != 'success'
+        run: exit 1
       
       #- name: Clang unit tests with -fsanitize=address
       #  run: |
-      #    export LLVM_VER=19.1.1
+      #    export LLVM_VER=19.1.3
       #    export PATH="/home/LLVM-${LLVM_VER}/bin:${PATH}"
       #    cd ${{ github.workspace }}/build_clang
       #    ASAN_SYMBOLIZER_PATH=llvm-symbolizer ASAN_OPTIONS=detect_stack_use_after_return=1:check_initialization_order=1:detect_leaks=1:atexit=1:abort_on_error=1 ./larra_xmpp_tests

.vscode/tasks.json

@@ -104,7 +104,7 @@
             "presentation": {
                 "clear": true
             },
-            "hide": true,
+            "hide": false,
             "group": {
                 "kind": "build"
             }

examples/src/connect.cpp

@@ -8,8 +8,6 @@
 #include <larra/printer_stream.hpp>
 #include <print>
 
-#include "larra/bind.hpp"
-
 namespace iq = larra::xmpp::iq;
 
 auto Coroutine() -> boost::asio::awaitable<void> {
@@ -53,7 +51,7 @@ auto Coroutine() -> boost::asio::awaitable<void> {
 }
 
 auto main() -> int {
-  spdlog::set_level(spdlog::level::debug);
+  spdlog::set_level(spdlog::level::trace);
   boost::asio::io_context io_context;
   boost::asio::co_spawn(io_context, Coroutine(), boost::asio::detached);
   io_context.run();

library/include/larra/bind.hpp

@@ -14,12 +14,12 @@ struct Bind {
 
   std::optional<FullJid> jid;
 
-  friend constexpr auto operator<<(xmlpp::Element* element, const Bind& Bind) {
+  friend constexpr auto operator<<(xmlpp::Element* element, const Bind& bind) {
     element->set_attribute("xmlns", Bind::kDefaultNamespace);
 
-    if(Bind.jid) {
+    if(bind.jid) {
       auto* jid_el = element->add_child_element("jid");
-      jid_el->add_child_text(ToString(*Bind.jid));
+      jid_el->add_child_text(ToString(*bind.jid));
     }
   }
   [[nodiscard]] static constexpr auto Parse(xmlpp::Element* element) -> Bind {

library/include/larra/client/client.hpp

@@ -11,23 +11,20 @@
 #include <boost/asio/ssl.hpp>
 #include <boost/asio/use_awaitable.hpp>
 #include <charconv>
+#include <larra/bind.hpp>
 #include <larra/client/challenge_response.hpp>
 #include <larra/client/options.hpp>
 #include <larra/client/starttls_response.hpp>
 #include <larra/client/xmpp_client_stream_features.hpp>
 #include <larra/encryption.hpp>
 #include <larra/features.hpp>
+#include <larra/roster.hpp>
 #include <larra/stream.hpp>
 #include <larra/user_account.hpp>
 #include <larra/xml_stream.hpp>
 #include <ranges>
 #include <utility>
 
-#include "larra/bind.hpp"
-#include "larra/iq.hpp"
-#include "larra/jid.hpp"
-#include "larra/roster.hpp"
-
 namespace rng = std::ranges;
 namespace views = std::views;
 namespace iq = larra::xmpp::iq;
@@ -97,7 +94,7 @@ struct Client {
     const auto roster_result = co_await connection.template Read<::iq::ResultRoster>();
     roster = std::move(roster_result.payload);
 
-    SPDLOG_INFO("{}", ToString(roster));
+    SPDLOG_INFO("New roster: {}", ToString(roster));
     co_return;
   }
 

library/include/larra/printer_stream.hpp

@@ -35,6 +35,8 @@ template <typename Socket>
 struct PrintStream : Socket {
   using Socket::Socket;
   PrintStream(PrintStream&&) = default;
+  constexpr PrintStream(Socket&& sock) : Socket(std::move(sock)) {
+  }
   using Executor = Socket::executor_type;
   template <typename ConstBufferSequence,
             BOOST_ASIO_COMPLETION_TOKEN_FOR(void(boost::system::error_code, std::size_t))

library/include/larra/roster.hpp

@@ -2,7 +2,6 @@
 #include <libxml++/libxml++.h>
 #include <spdlog/spdlog.h>
 
-#include <cassert>
 #include <larra/iq.hpp>
 #include <larra/jid.hpp>
 #include <larra/utils.hpp>
@@ -19,14 +18,14 @@ struct Roster {
   std::vector<BareJid> items;
 
   friend auto ToString(const Roster& roster) -> std::string {
-    static constexpr std::string_view prefix = "Roster: [";
+    static constexpr std::string_view prefix = "Roster: [\n\t";
     static constexpr std::string_view suffix = "]";
+    // \n\r\t
     std::size_t total_length = std::ranges::fold_left(roster.items | std::views::transform([](const auto& el) {
-                                                        return larra::xmpp::utils::AccumulateFieldLength(el) + 2;
+                                                        return larra::xmpp::utils::AccumulateFieldLength(el) + 3;
                                                       }),
-                                                      std::size_t{0},
-                                                      std::plus<>{}) +
-                               prefix.length() + suffix.length();
+                                                      prefix.length() + suffix.length(),
+                                                      std::plus<>{});
 
     std::string s;
     s.resize(total_length);
@@ -35,14 +34,13 @@ struct Roster {
       s += ToString(el);
       s += "\n\t";
     }
-    s += suffix;
-
-    return s;
+    return s += suffix;
   }
   friend constexpr auto operator<<(xmlpp::Element* element, const Roster& roster) {
-    element->set_attribute("xmlns", "jabber:iq:roster");
-    // TODO: Add adding elements to xmlpp::Element
-    assert(false);
+    element->set_attribute("xmlns", Roster::kDefaultNamespace);
+    std::ranges::for_each(roster.items, [element](const auto& item) {
+      element->add_child_element("item")->set_attribute("jid", ToString(item));
+    });
   }
   [[nodiscard]] static constexpr auto Parse(xmlpp::Element* element) -> Roster {
     const auto& item_nodes = element->get_children("item");

library/include/larra/serialization.hpp

@@ -2,7 +2,9 @@
 #include <libxml++/libxml++.h>
 #include <spdlog/spdlog.h>
 
+#include <larra/serialization/error.hpp>
 #include <nameof.hpp>
+#include <ranges>
 #include <string>
 #include <utempl/utils.hpp>
 
@@ -87,10 +89,6 @@ struct SerializationBase {
                  }) {
       return T::StartCheck(element);
     } else {
-      if (element)
-      {
-        SPDLOG_DEBUG("kDefaultName: {}, get_name: {}", kDefaultName, element->get_name());
-      }
       return element && element->get_name() == kDefaultName;
     }
   };
@@ -100,7 +98,8 @@ template <typename T>
 struct Serialization : SerializationBase<T> {
   [[nodiscard]] static constexpr auto Parse(xmlpp::Element* element) -> T {
     if(!Serialization::StartCheck(element)) {
-      throw std::runtime_error("StartCheck failed");
+      throw serialization::ParsingError{
+          std::format("[{}: {}] parsing error: [ StartCheck failed ]", Serialization::kDefaultName, nameof::nameof_full_type<T>())};
     }
     return T::Parse(element);
   }
@@ -171,8 +170,8 @@ struct Serialization<std::variant<Ts...>> : SerializationBase<> {
   }
   static constexpr auto Serialize(xmlpp::Element* element, const std::variant<Ts...>& object) -> void {
     std::visit(
-        [&](const auto& object) {
-          element << object;
+        [&]<typename T>(const T& object) {
+          Serialization<T>::Serialize(element, object);
         },
         object);
   }
@@ -193,4 +192,42 @@ struct Serialization<std::monostate> : SerializationBase<> {
   }
 };
 
+template <typename T>
+struct Serialization<std::vector<T>> : SerializationBase<> {
+  static constexpr auto Parse(xmlpp::Element* element) -> std::vector<T> {
+    return element->get_children(Serialization<T>::kDefaultName) | std::views::transform([](xmlpp::Node* node) {
+             auto itemElement = dynamic_cast<xmlpp::Element*>(node);
+             if(!itemElement) {
+               throw serialization::ParsingError{"Can't convert xmlpp::Node to xmlpp::Element ]"};
+             }
+             return Serialization<T>::Parse(itemElement);
+           }) |
+           std::ranges::to<std::vector<T>>();
+  }
+  static constexpr auto TryParse(xmlpp::Element* element) -> std::optional<std::vector<T>> {
+    auto chd = element->get_children(Serialization<T>::kDefaultName);
+    auto range = chd | std::views::transform([](xmlpp::Node* node) -> std::optional<T> {
+                   auto itemElement = dynamic_cast<xmlpp::Element*>(node);
+                   if(!itemElement) {
+                     return std::nullopt;
+                   }
+                   return Serialization<T>::TryParse(itemElement);
+                 });
+    std::vector<T> response;
+    response.reserve(chd.size());
+    for(auto& value : range) {
+      if(!value) {
+        return std::nullopt;
+      }
+      response.push_back(std::move(*value));
+    }
+    return response;
+  }
+  static constexpr auto Serialize(xmlpp::Element* node, const std::vector<T>& value) -> void {
+    for(const T& element : value) {
+      Serialization<T>::Serialize(node->add_child_element(Serialization<T>::kDefaultName), element);
+    }
+  }
+};
+
 }  // namespace larra::xmpp

library/include/larra/serialization/auto.hpp

@@ -0,0 +1,346 @@
+#pragma once
+#include <libxml++/libxml++.h>
+
+#include <boost/pfr.hpp>
+#include <larra/serialization.hpp>
+#include <larra/serialization/error.hpp>
+#include <ranges>
+#include <utempl/constexpr_string.hpp>
+#include <utempl/tuple.hpp>
+#include <utempl/utils.hpp>
+#include <variant>
+
+namespace larra::xmpp::serialization {
+
+template <typename T>
+struct Tag {};
+
+template <typename T>
+inline constexpr auto kSerializationConfig = std::monostate{};
+
+template <typename T>
+inline constexpr auto kDeserializationConfig = kSerializationConfig<T>;
+
+template <typename T>
+constexpr auto Parse(xmlpp::Element* element, Tag<T> = {}) -> T
+  requires(!std::same_as<std::decay_t<decltype(kDeserializationConfig<T>)>, std::monostate>);
+
+template <typename T>
+constexpr auto Parse(xmlpp::Element* element, Tag<T> = {}) -> T;
+
+template <typename T>
+constexpr auto TryParse(xmlpp::Element* element, Tag<T> = {}) -> std::optional<T> {
+  return Serialization<std::optional<T>>::Parse(element);
+}
+
+template <typename T>
+constexpr auto Serialize(xmlpp::Element* node, const T& element) -> void
+  requires(!std::same_as<std::decay_t<decltype(kSerializationConfig<T>)>, std::monostate>);
+
+template <typename T>
+constexpr auto Serialize(xmlpp::Element* node, const T& element) -> void;
+
+template <typename T>
+struct MetaInfo {
+  static constexpr std::size_t kSize = boost::pfr::tuple_size_v<T>;
+  template <std::size_t I>
+  using TupleElement = boost::pfr::tuple_element_t<I, T>;
+
+  template <std::size_t I>
+  static constexpr std::string_view kFieldName = boost::pfr::get_name<I, T>();
+
+  template <typename Self, std::size_t I>
+  static constexpr auto Get(Self&& self) -> decltype(auto) {
+    return boost::pfr::get<I>(std::forward<Self>(self));
+  }
+};
+
+template <typename MainT, std::size_t Element>
+struct FieldInfo {
+  using Main = MainT;
+  using Info = MetaInfo<Main>;
+  static inline const std::string kName = [] {
+    if constexpr(requires { Info::template TupleElement<Element>::kDefaultName; }) {
+      return Info::template TupleElement<Element>::kDefaultName;
+    } else {
+      return static_cast<std::string>(Info::template kFieldName<Element>);
+    }
+  }();
+};
+
+template <typename T>
+struct Config {};
+
+// GCC workaround: operator==
+
+struct AttributeConfig {
+  auto operator==(const AttributeConfig&) const -> bool = default;
+  template <typename T>
+  constexpr auto operator==(const Config<T>&) const -> bool {
+    return false;
+  }
+  template <typename T>
+  friend constexpr auto operator==(const Config<T>&, const AttributeConfig&) -> bool {
+    return false;
+  }
+};
+
+template <typename T>
+constexpr auto operator==(const Config<T>&, const Config<T>&) -> bool {
+  return false;
+}
+
+template <typename T>
+struct Config<std::optional<T>> {
+  std::optional<T> defaultValue = std::nullopt;
+  bool strict = true;
+  std::optional<Config<T>> main = std::nullopt;
+};
+
+namespace impl {
+template <typename T>
+concept HasParse = requires(xmlpp::Element* e) {
+  { T::Parse(e) } -> std::same_as<T>;
+};
+
+template <typename T, typename V>
+struct Config : V {
+  using V::V;
+  constexpr Config()
+    requires HasParse<T>
+      : V(::larra::xmpp::serialization::Config<T>{}) {
+  }
+
+  constexpr Config()
+    requires(!HasParse<T>)
+      : V(AttributeConfig{}) {
+  }
+  constexpr auto Base() const -> const V& {
+    return static_cast<const V&>(*this);
+  }
+  using type = T;
+};
+
+}  // namespace impl
+
+template <typename T>
+struct ElementConfig {
+  using type = impl::Config<T, std::variant<AttributeConfig, Config<T>>>;
+};
+
+template <typename T, auto& Config, typename Info>
+struct ElementSerializer {
+  static constexpr auto Parse(xmlpp::Element* element) {
+    auto node = element->get_first_child(Info::kName);
+    if(!node) {
+      throw ElementParsingError(std::format("[{}: {}] parsing error: [ Not found ]", Info::kName, nameof::nameof_full_type<T>()));
+    }
+    auto elementNode = dynamic_cast<xmlpp::Element*>(node);
+    if(!elementNode) {
+      throw ElementParsingError(std::format("[{}: {}] parsing error: [ Invalid node ]", Info::kName, nameof::nameof_full_type<T>()));
+    }
+    try {
+      return ::larra::xmpp::serialization::Parse(elementNode, Tag<T>{});
+    } catch(const std::exception& error) {
+      throw ElementParsingError(std::format("[{}: {}] parsing error: [ {} ]", Info::kName, nameof::nameof_full_type<T>(), error.what()));
+    }
+  }
+
+  static constexpr auto Serialize(xmlpp::Element* node, const T& element) {
+    auto created = node->add_child_element(Info::kName);
+    if(!node) {
+      throw ElementSerializaionError(
+          std::format("[{}: {}] serialization error: [ node creation failed ]", Info::kName, nameof::nameof_full_type<T>()));
+    }
+    try {
+      ::larra::xmpp::serialization::Serialize(created, element);
+    } catch(const std::exception& err) {
+      throw ElementSerializaionError(
+          std::format("[{}: {}] serialization error: [ {} ]", Info::kName, nameof::nameof_full_type<T>(), err.what()));
+    }
+  }
+};
+
+template <typename T, auto& Config, typename Info>
+struct ElementSerializer<std::optional<T>, Config, Info> {
+  static constexpr auto Parse(xmlpp::Element* element) -> std::optional<T> {
+    return [&] {
+      auto node = element->get_first_child(Info::kName);
+      if(!node) {
+        return std::nullopt;
+      }
+      auto elementNode = dynamic_cast<xmlpp::Element*>(node);
+      if(!elementNode) {
+        return std::nullopt;
+      }
+      if constexpr(Config.strict) {
+        return ElementSerializer<T, Config.main, Info>::Parse(element);
+      } else {
+        return ElementSerializer<T, Config.main, Info>::TryParse(element);
+      }
+    }()
+               .or_else([] {
+                 return Config.defaultValue;
+               });
+  }
+  static constexpr auto Serialize(xmlpp::Element* node, const std::optional<T>& element) {
+    if(element) {
+      ElementSerializer<T, Config.main, Info>::Serialize(node, *element);
+    } else if(Config.defaultValue) {
+      Serialize(node, Config.defaultValue);
+    }
+  }
+};
+
+template <typename T, auto& Config, typename Info>
+struct ElementSerializer<std::vector<T>, Config, Info> {
+  // TODO(sha512sum): Add Config and main options instead use Serialization<std::vector<T>>
+  static constexpr auto Parse(xmlpp::Element* element) {
+    try {
+      return Serialization<std::vector<T>>::Parse(element);
+    } catch(const std::exception& error) {
+      throw ElementParsingError(
+          std::format("[{}: {}] parsing error: [ {} ]", Info::kName, nameof::nameof_full_type<std::vector<T>>(), error.what()));
+    }
+  }
+  static constexpr auto Serialize(xmlpp::Element* node, const std::vector<T>& element) {
+    try {
+      return Serialization<std::vector<T>>::Serialize(node, element);
+    } catch(const std::exception& error) {
+      throw ElementSerializaionError(
+          std::format("[{}: {}] serialization error: [ {} ]", Info::kName, nameof::nameof_full_type<std::vector<T>>(), error.what()));
+    }
+  }
+};
+
+template <typename T, typename Info>
+struct AttributeSerializer {
+  static constexpr auto Parse(xmlpp::Element* element) -> T {
+    auto node = element->get_attribute(Info::kName);
+    if(!node) {
+      throw AttributeParsingError(std::format("Attribute [{}: {}] parsing error", Info::kName, nameof::nameof_full_type<T>()));
+    }
+    if constexpr(requires(std::string_view view) { T::Parse(view); }) {
+      return T::Parse(node->get_value());
+    } else {
+      return node->get_value();
+    }
+  }
+  static constexpr auto Serialize(xmlpp::Element* element, const T& obj) {
+    if constexpr(requires {
+                   { ToString(obj) } -> std::convertible_to<const std::string&>;
+                 }) {
+      element->set_attribute(Info::kName, ToString(obj));
+    } else {
+      element->set_attribute(Info::kName, obj);
+    }
+  }
+};
+
+template <typename T, typename Info>
+struct AttributeSerializer<std::optional<T>, Info> {
+  static constexpr auto Parse(xmlpp::Element* element) -> std::optional<T> {
+    auto node = element->get_attribute(Info::kName);
+    return node ? std::optional{AttributeSerializer<T, Info>::Parse(element)} : std::nullopt;
+  }
+  static constexpr auto Serialize(xmlpp::Element* element, const std::optional<T>& obj) {
+    if(obj) {
+      AttributeSerializer<T, Info>::Serialize(element, *obj);
+    }
+  }
+};
+
+namespace impl {
+
+template <typename T>
+consteval auto FindElement(std::string_view field, utempl::TypeList<T> = {}) {
+  auto fields = boost::pfr::names_as_array<T>();
+  return std::ranges::find(fields, field) - fields.begin();
+}
+
+template <auto& Config, typename Info>
+auto ParseField(xmlpp::Element* main) -> std::decay_t<decltype(Config)>::type {
+  using Type = std::decay_t<decltype(Config)>::type;
+  if constexpr(std::holds_alternative<AttributeConfig>(Config.Base())) {
+    return AttributeSerializer<Type, Info>::Parse(main);
+  } else {
+    return ElementSerializer<Type, Config, Info>::Parse(main);
+  }
+}
+
+template <auto& Config, typename Info, typename T>
+auto SerializeField(xmlpp::Element* main, const T& obj) {
+  if constexpr(std::holds_alternative<AttributeConfig>(Config.Base())) {
+    AttributeSerializer<T, Info>::Serialize(main, obj);
+  } else {
+    ElementSerializer<T, Config, Info>::Serialize(main, obj);
+  }
+}
+
+}  // namespace impl
+
+template <typename T>
+struct SerializationConfig {
+  decltype([] {
+    return [](auto... is) {
+      return utempl::Tuple<typename ElementConfig<boost::pfr::tuple_element_t<*is, T>>::type...>{};
+    } | utempl::kSeq<boost::pfr::tuple_size_v<T>>;
+  }()) tuple{};
+  template <std::size_t I, typename Self>  // NOLINTNEXTLINE
+  consteval auto With(this Self&& self, ElementConfig<boost::pfr::tuple_element_t<I, T>>::type config) -> SerializationConfig {
+    auto tuple = std::forward_like<Self>(self.tuple);
+    Get<I>(tuple) = std::move(config);
+    return {std::move(tuple)};
+  }
+  template <utempl::ConstexprString Name, typename Self>
+  constexpr auto With(this Self&& self, ElementConfig<boost::pfr::tuple_element_t<impl::FindElement<T>(Name), T>>::type config)
+      -> SerializationConfig {
+    return std::forward<Self>(self).template With<impl::FindElement<T>(Name)>(std::move(config));
+  }
+};
+
+template <typename T>
+constexpr auto Parse(xmlpp::Element* element, Tag<T>) -> T {
+  return Serialization<T>::Parse(element);
+}
+template <typename T>
+constexpr auto Parse(xmlpp::Element* element, Tag<T>) -> T
+  requires(!std::same_as<std::decay_t<decltype(kDeserializationConfig<T>)>, std::monostate>)
+{
+  static constexpr SerializationConfig config = kDeserializationConfig<T>;
+  constexpr auto tuple = utempl::Map(config.tuple, [](auto& ref) {
+    return &ref;
+  });
+  return utempl::Unpack(utempl::PackConstexprWrapper<utempl::Enumerate(tuple)>(), [&](auto... configs) {
+    try {
+      return T{impl::ParseField<*((*configs).second), FieldInfo<T, (*configs).first>>(element)...};
+    } catch(const ParsingError& error) {
+      throw ElementParsingError(std::format("[{}] parsing error: [ {} ]", nameof::nameof_full_type<T>(), error.what()));
+    }
+  });
+}
+
+template <typename T>
+constexpr auto Serialize(xmlpp::Element* node, const T& element) -> void
+  requires(!std::same_as<std::decay_t<decltype(kSerializationConfig<T>)>, std::monostate>)
+{
+  static constexpr SerializationConfig config = kSerializationConfig<T>;
+  constexpr auto tuple = utempl::Map(config.tuple, [](auto& ref) {
+    return &ref;
+  });
+
+  return utempl::Unpack(utempl::PackConstexprWrapper<utempl::Enumerate(tuple)>(), [&](auto... configs) {
+    try {
+      (impl::SerializeField<*((*configs).second), FieldInfo<T, (*configs).first>>(node, boost::pfr::get<(*configs).first>(element)), ...);
+    } catch(const ParsingError& error) {
+      throw ElementParsingError(std::format("[{}] parsing error: [ {} ]", nameof::nameof_full_type<T>(), error.what()));
+    }
+  });
+}
+
+template <typename T>
+constexpr auto Serialize(xmlpp::Element* node, const T& element) -> void {
+  Serialization<T>::Serialize(node, element);
+}
+
+}  // namespace larra::xmpp::serialization

library/include/larra/serialization/error.hpp

@@ -0,0 +1,30 @@
+#pragma once
+#include <stdexcept>
+
+namespace larra::xmpp::serialization {
+
+struct ParsingError : std::runtime_error {
+  using std::runtime_error::runtime_error;
+};
+
+struct AttributeParsingError : ParsingError {
+  using ParsingError::ParsingError;
+};
+
+struct ElementParsingError : ParsingError {
+  using ParsingError::ParsingError;
+};
+
+struct SerializationError : std::runtime_error {
+  using std::runtime_error::runtime_error;
+};
+
+struct AttributeSerializationError : SerializationError {
+  using SerializationError::SerializationError;
+};
+
+struct ElementSerializaionError : SerializationError {
+  using SerializationError::SerializationError;
+};
+
+}  // namespace larra::xmpp::serialization

tests/roster.cpp

@@ -1,7 +1,6 @@
 #include <gtest/gtest.h>
 
 #include <larra/roster.hpp>
-#include <ranges>
 
 #include "larra/jid.hpp"
 
@@ -14,17 +13,27 @@ TEST(Roster, SerializeAndParse) {
   roster.payload.items.emplace_back("u2", "s2");
   roster.payload.items.emplace_back("u3", "s3");
 
-  using S = Serialization<iq::GetRoster>;
   xmlpp::Document doc;
   auto node = doc.create_root_node("iq");
   node << roster;
-  auto parse_res = iq::Roster::Parse(node);
 
-  ASSERT_EQ(roster.payload.items.size(), parse_res.items.size());
-  for(const auto& [idx, expect_el, parsed_el] : std::views::zip(std::views::iota(0), roster.payload.items, parse_res.items)) {
+  auto parse_res = decltype(roster)::Parse(node);
+
+  ASSERT_EQ(roster.payload.items.size(), parse_res.payload.items.size());
+  for(const auto& [idx, expect_el, parsed_el] : std::views::zip(std::views::iota(0), roster.payload.items, parse_res.payload.items)) {
     EXPECT_EQ(expect_el, parsed_el) << "Mismatched on idx: " << idx;
     // std::cerr << "        " << "idx: " << idx << "; expect_el: " << expect_el << "; parsed_el: " << parsed_el << '\n';
   }
 }
 
+TEST(Roster, Print) {
+  FullJid jid{.username = "test", .server = "server", .resource = "res"};  // NOLINT
+  auto roster = iq::MakeGetRoster(jid);
+  roster.payload.items.emplace_back("u1", "s1");
+  roster.payload.items.emplace_back("u2", "s2");
+  roster.payload.items.emplace_back("u3", "s3");
+
+  EXPECT_NO_THROW({ std::cerr << "[          ] Roster payload: " << ToString(roster.payload) << '\n'; });
+}
+
 }  // namespace larra::xmpp

tests/serialization.cpp

@@ -1,8 +1,13 @@
 #include <gtest/gtest.h>
 
+#include <larra/jid.hpp>
 #include <larra/serialization.hpp>
+#include <larra/serialization/auto.hpp>
+#include <larra/serialization/error.hpp>
 #include <larra/stream_error.hpp>
 
+using namespace std::literals;
+
 namespace larra::xmpp {
 
 TEST(Parse, Variant) {
@@ -21,8 +26,188 @@ TEST(Serialize, Variant) {
   auto node = doc.create_root_node("stream:error");
   S::Serialize(node, data);
   EXPECT_EQ(doc.write_to_string(),
-            std::string_view{"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<stream:error><unsupported-stanza-type "
-                             "xmlns=\"urn:ietf:params:xml:ns:xmpp-streams\"/></stream:error>\n"});
+            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<stream:error><unsupported-stanza-type "
+            "xmlns=\"urn:ietf:params:xml:ns:xmpp-streams\"/></stream:error>\n"sv);
+}
+
+namespace tests::serialization {
+
+struct SomeStruct {
+  static constexpr auto kDefaultName = "some";
+  std::string value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct;
+  friend auto operator<<(xmlpp::Element* element, const SomeStruct& self);
+  constexpr auto operator==(const SomeStruct&) const -> bool = default;
+};
+
+struct SomeStruct2 {
+  static constexpr auto kDefaultName = "some2";
+  SomeStruct value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct2;
+  friend auto operator<<(xmlpp::Element* element, const SomeStruct2& self);
+};
+
+struct SomeStruct3 {
+  static constexpr auto kDefaultName = "some3";
+  int value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct3;
+};
+
+struct SomeStruct4 {
+  static constexpr auto kDefaultName = "some4";
+  SomeStruct3 value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct4;
+};
+
+struct SomeStruct5 {
+  static constexpr auto kDefaultName = "some5";
+  BareJid value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct5;
+  friend auto operator<<(xmlpp::Element* element, const SomeStruct5& self);
+};
+
+struct SomeStruct6 {
+  static constexpr auto kDefaultName = "some6";
+  std::vector<SomeStruct> some;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct6;
+};
+
+struct SomeStruct7 {
+  static constexpr auto kDefaultName = "some7";
+  std::optional<FullJid> value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct7;
+};
+
+}  // namespace tests::serialization
+
+namespace serialization {
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct> = SerializationConfig<tests::serialization::SomeStruct>{};
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct2> = SerializationConfig<tests::serialization::SomeStruct2>{};
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct4> = SerializationConfig<tests::serialization::SomeStruct4>{};
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct5> = SerializationConfig<tests::serialization::SomeStruct5>{};
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct6> =
+    SerializationConfig<tests::serialization::SomeStruct6>{}.With<"some">({Config<std::vector<tests::serialization::SomeStruct>>{}});
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct7> = SerializationConfig<tests::serialization::SomeStruct7>{};
+
+}  // namespace serialization
+
+namespace tests::serialization {
+
+auto SomeStruct::Parse(xmlpp::Element* element) -> SomeStruct {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct>(element);
+}
+
+auto SomeStruct2::Parse(xmlpp::Element* element) -> SomeStruct2 {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct2>(element);
+}
+
+auto SomeStruct3::Parse(xmlpp::Element*) -> SomeStruct3 {
+  return {.value = 42};  // NOLINT
+}
+
+auto SomeStruct4::Parse(xmlpp::Element* element) -> SomeStruct4 {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct4>(element);
+}
+
+auto SomeStruct5::Parse(xmlpp::Element* element) -> SomeStruct5 {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct5>(element);
+}
+
+auto SomeStruct6::Parse(xmlpp::Element* element) -> SomeStruct6 {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct6>(element);
+}
+
+auto SomeStruct7::Parse(xmlpp::Element* element) -> SomeStruct7 {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct7>(element);
+}
+
+auto operator<<(xmlpp::Element* element, const SomeStruct& self) {
+  ::larra::xmpp::serialization::Serialize(element, self);
+}
+
+auto operator<<(xmlpp::Element* element, const SomeStruct2& self) {
+  ::larra::xmpp::serialization::Serialize(element, self);
+}
+
+auto operator<<(xmlpp::Element* element, const SomeStruct5& self) {
+  ::larra::xmpp::serialization::Serialize(element, self);
+}
+
+}  // namespace tests::serialization
+
+TEST(AutoParse, Basic) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some2");
+  node = node->add_child_element("some");
+  node->set_attribute("value", "Hello");
+  auto a = Serialization<tests::serialization::SomeStruct>::Parse(node);
+  EXPECT_EQ(a.value, "Hello"sv);
+  auto b = Serialization<tests::serialization::SomeStruct2>::Parse(doc.get_root_node());
+  EXPECT_EQ(b.value.value, "Hello"sv);
+  EXPECT_THROW(std::ignore = tests::serialization::SomeStruct2::Parse(node), serialization::ParsingError);
+  auto node2 = node->add_child_element("some4");
+  node2->add_child_element("some3");
+  auto c = Serialization<tests::serialization::SomeStruct4>::Parse(node2);
+  EXPECT_EQ(c.value.value, 42);
+}
+
+TEST(AutoParse, Attribute) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some5");
+  node->set_attribute("value", "user@server.i2p");
+  auto a = Serialization<tests::serialization::SomeStruct5>::Parse(node);
+  EXPECT_EQ(a.value.server, "server.i2p"sv);
+  EXPECT_EQ(a.value.username, "user"sv);
+}
+
+TEST(AutoParse, Vector) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some6");
+  for(auto i : std::views::iota(0, 10)) {
+    auto child = node->add_child_element("some");
+    child->set_attribute("value", std::format("Hello {}", i));
+  }
+  auto value = Serialization<tests::serialization::SomeStruct6>::Parse(node);
+  EXPECT_EQ(value.some, std::views::iota(0, 10) | std::views::transform([](auto i) -> tests::serialization::SomeStruct {
+                          return {.value = std::format("Hello {}", i)};
+                        }) | std::ranges::to<std::vector<tests::serialization::SomeStruct>>());
+}
+
+TEST(AutoParse, Optional) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some7");
+  auto value = Serialization<tests::serialization::SomeStruct7>::Parse(node).value;
+  EXPECT_EQ(value, std::nullopt);
+  node->set_attribute("value", "user@server.i2p/resource");
+  auto value2 = Serialization<tests::serialization::SomeStruct7>::Parse(node).value;
+  FullJid expectData{.username = "user", .server = "server.i2p", .resource = "resource"};
+  EXPECT_EQ(value2, expectData);
+}
+
+TEST(AutoSerialize, Basic) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some2");
+  node << tests::serialization::SomeStruct2{.value = {.value = "testData"}};
+  EXPECT_EQ(doc.write_to_string(), "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<some2><some value=\"testData\"/></some2>\n");
+}
+
+TEST(AutoSerialize, Attribute) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some5");
+  node << tests::serialization::SomeStruct5{.value = {.username = "user", .server = "server.i2p"}};
+  EXPECT_EQ(doc.write_to_string(), "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<some5 value=\"user@server.i2p\"/>\n");
 }
 
 }  // namespace larra::xmpp