cpp-stateful-serializer/test/jsonizer_test.cxx

//
//  jsonizer_test.cxx
//  serializer-test
//
//  Created by Sam Jaffe on 3/16/23.
//

#include "xcode_gtest_helper.h"

#include <map>
#include <set>
#include <vector>

#include <serializer/jsonizer.tpp>

#define CONCAT2(A, B) A##B
#define CONCAT(A, B) CONCAT2(A, B)

#define EXPECT_ROUNDTRIP(izer, value, as_json)                                 \
  Json::Value CONCAT(json_, __LINE__) = izer.to_json(value);                   \
  EXPECT_THAT(CONCAT(json_, __LINE__), as_json);                               \
  EXPECT_THAT(izer.from_json<decltype(value)>(CONCAT(json_, __LINE__)), value)

using std::operator""s;
using std::operator""sv;
using namespace magic_enum::bitwise_operators;

using testing::Field;
using testing::IsNull;
using testing::NotNull;
using testing::Pointee;

enum class Color { RED, BLUE, GREEN };
enum class Mask { LEFT = 1, RIGHT = 2 };

Json::Value operator""_json(char const * str, size_t len) {
  Json::Value rval;
  Json::Reader reader;
  if (!reader.parse(str, str + len, rval)) {
    throw std::invalid_argument(reader.getFormattedErrorMessages());
  }
  return rval;
}

TEST(JsonizerTest, ParsesNumbers) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, 1.5f, "1.5"_json);
  EXPECT_ROUNDTRIP(izer, 1.5, "1.5"_json);
  EXPECT_ROUNDTRIP(izer, 3, "3"_json);
  EXPECT_ROUNDTRIP(izer, true, "true"_json);
}

TEST(JsonizerTest, ParsesStrings) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, "hello"s, "\"hello\""_json);
  EXPECT_THAT(izer.to_json("hello"), "\"hello\""_json);
  EXPECT_THAT(izer.to_json("hello"sv), "\"hello\""_json);
}

TEST(JsonizerTest, ParsesEnums) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, Color::RED, "\"RED\""_json);
  EXPECT_TRUE(magic_enum::detail::is_flags_v<Mask>);
  EXPECT_ROUNDTRIP(izer, Mask::LEFT | Mask::RIGHT, "\"LEFT|RIGHT\""_json);
}

TEST(JsonizerTest, ParsesTuples) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, std::make_pair(1, true), "[1, true]"_json);
  EXPECT_ROUNDTRIP(izer, std::make_tuple(1, true, 1.5, "hi"s),
                   "[1, true, 1.5, \"hi\"]"_json);
}

TEST(JsonizerTest, ParsesCollection) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, std::vector({1, 2, 3, 1}), "[1, 2, 3, 1]"_json);
  EXPECT_ROUNDTRIP(izer, std::set({1, 2, 3, 1}), "[1, 2, 3]"_json);
}

TEST(JsonizerTest, ThrowsOnParsingCollectionFromNonArray) {
  serializer::Jsonizer izer;
  std::vector<int> out;
  EXPECT_THROW(izer.from_json(out, "1"_json), std::invalid_argument);
}

TEST(JsonizerTest, ParsesAssociative) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, (std::map<int, int>{{1, 2}, {3, 1}}),
                   "{\"1\":2, \"3\":1}"_json);
}

TEST(JsonizerTest, AssociativeCanParseFromPairListOrObject) {
  using Type = std::map<std::string, int>;
  serializer::Jsonizer izer;

  EXPECT_THAT(izer.from_json<Type>("[[\"A\", 2], [\"B\", 1]]"_json),
              (Type{{"A", 2}, {"B", 1}}));

  EXPECT_THAT(izer.from_json<Type>("{ \"A\": 2, \"B\": 1 }"_json),
              (Type{{"A", 2}, {"B", 1}}));
}

TEST(JsonizerTest, AssociativeWithNonTrivialKeyIsPairList) {
  using Type = std::map<std::pair<int, int>, int>;
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, (Type{{{1, 2}, 1}, {{2, 1}, 2}}),
                   "[[[1, 2], 1], [[2, 1], 2]]"_json);
}

TEST(JsonizerTest, ThrowsOnParsingAssociativeFromNonCollection) {
  serializer::Jsonizer izer;
  std::map<int, int> out;
  EXPECT_THROW(izer.from_json(out, "1"_json), std::invalid_argument);
}

struct Cacheable {
  std::string name;
};

template <>
void serializer::Jsonizer::from_json(Cacheable & value,
                                     Json::Value const & json) const {
  from_json(value.name, json["name"]);
}

TEST(JsonizerTest, CanAttemptToLoadFromCache) {
  serializer::Jsonizer izer;
  std::shared_ptr<Cacheable const> ptr;

  EXPECT_THROW(izer.from_json(ptr, "\"ONE\""_json), std::domain_error);
  EXPECT_THAT(ptr, IsNull());

  EXPECT_NO_THROW(izer.from_json(ptr, "{\"name\":\"ONE\"}"_json));
  EXPECT_THAT(ptr, NotNull());
  EXPECT_THAT(ptr, Pointee(Field(&Cacheable::name, "ONE")));
}

struct Serializable {
  using serial_type = std::map<int, int>;

  Serializable(std::vector<int> value = {}) : value(value) {}

  Serializable(serial_type vals) {
    for (auto [k, v] : vals) {
      while (v--) {
        value.push_back(k);
      }
    }
  }

  operator serial_type() const {
    serial_type rval;
    for (auto v : value) {
      ++rval[v];
    }
    return rval;
  }

  std::vector<int> value;
};

bool operator==(Serializable const & lhs, Serializable const & rhs) {
  return lhs.value == rhs.value;
}

TEST(JsonizerTest, CanConstructFromAltType) {
  serializer::Jsonizer izer;
  EXPECT_ROUNDTRIP(izer, Serializable({1, 1, 1, 1, 2, 2, 2, 3, 3, 4}),
                   "{\"1\":4, \"2\":3, \"3\":2, \"4\":1}"_json);
}