json/tests/src/unit-regression1.cpp

//     __ _____ _____ _____
//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
// |  |  |__   |  |  | | | |  version 3.12.0
// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT

#include "doctest_compatibility.h"

// for some reason including this after the json header leads to linker errors with VS 2017...
#include <locale>

// skip tests if JSON_DisableEnumSerialization=ON (#4384)
#if defined(JSON_DISABLE_ENUM_SERIALIZATION) && (JSON_DISABLE_ENUM_SERIALIZATION == 1)
    #define SKIP_TESTS_FOR_ENUM_SERIALIZATION
#endif

#define JSON_TESTS_PRIVATE
#include <nlohmann/json.hpp>
using nlohmann::json;
#ifdef JSON_TEST_NO_GLOBAL_UDLS
    using namespace nlohmann::literals; // NOLINT(google-build-using-namespace)
#endif

#include <fstream>
#include <sstream>
#include <list>
#include <limits>
#include <cstdio>
#include "make_test_data_available.hpp"
#include "test_utils.hpp"

#include "fifo_map.hpp"

/////////////////////////////////////////////////////////////////////
// for #972
/////////////////////////////////////////////////////////////////////

template<class K, class V, class dummy_compare, class A>
using my_workaround_fifo_map = nlohmann::fifo_map<K, V, nlohmann::fifo_map_compare<K>, A>;
using my_json = nlohmann::basic_json<my_workaround_fifo_map>;

/////////////////////////////////////////////////////////////////////
// for #977
/////////////////////////////////////////////////////////////////////

namespace ns
{
struct foo
{
    int x;
};

template <typename, typename SFINAE = void>
struct foo_serializer;

template<typename T>
struct foo_serializer<T, typename std::enable_if<std::is_same<foo, T>::value>::type>
{
    template <typename BasicJsonType>
    static void to_json(BasicJsonType& j, const T& value)
    {
        j = BasicJsonType{{"x", value.x}};
    }
    template <typename BasicJsonType>
    static void from_json(const BasicJsonType& j, T& value)     // !!!
    {
        nlohmann::from_json(j.at("x"), value.x);
    }
};

template<typename T>
struct foo_serializer < T, typename std::enable_if < !std::is_same<foo, T>::value >::type >
{
    template <typename BasicJsonType>
    static void to_json(BasicJsonType& j, const T& value) noexcept // NOLINT(bugprone-exception-escape)
    {
        ::nlohmann::to_json(j, value);
    }
    template <typename BasicJsonType>
    static void from_json(const BasicJsonType& j, T& value)   //!!!
    {
        ::nlohmann::from_json(j, value);
    }
};
} // namespace ns

using foo_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t,
      std::uint64_t, double, std::allocator, ns::foo_serializer, std::vector<std::uint8_t>>;

/////////////////////////////////////////////////////////////////////
// for #805
/////////////////////////////////////////////////////////////////////

namespace
{
struct nocopy // NOLINT(cppcoreguidelines-special-member-functions,hicpp-special-member-functions)
{
    nocopy() = default;
    nocopy(const nocopy&) = delete;
    nocopy(nocopy&&) = delete;
    nocopy& operator=(const nocopy&) = delete;
    nocopy& operator=(nocopy&&) = delete;

    int val = 0;

    friend void to_json(json& j, const nocopy& n)
    {
        j = {{"val", n.val}};
    }
};
} // namespace

TEST_CASE("regression tests 1")
{
    SECTION("issue #60 - Double quotation mark is not parsed correctly")
    {
        SECTION("escape_doublequote")
        {
            const auto* s = R"(["\"foo\""])";
            const json j = json::parse(s);
            auto expected = R"(["\"foo\""])"_json;
            CHECK(j == expected);
        }
    }

    SECTION("issue #70 - Handle infinity and NaN cases")
    {
        // previously, NAN/INFINITY created a null value; now, the values are
        // properly stored, but are dumped as "null"
        SECTION("NAN value")
        {
            CHECK(json(NAN).dump() == "null");
            CHECK(json(json::number_float_t(NAN)).dump() == "null");
        }

        SECTION("infinity")
        {
            CHECK(json(INFINITY).dump() == "null");
            CHECK(json(json::number_float_t(INFINITY)).dump() == "null");
        }

        // With 3.0.0, the semantics of this changed: NAN and infinity are
        // stored properly inside the JSON value (no exception or conversion
        // to null), but are serialized as null.
        SECTION("NAN value")
        {
            json const j1 = NAN;
            CHECK(j1.is_number_float());
            json::number_float_t const f1{j1};
            CHECK(std::isnan(f1));

            json const j2 = static_cast<json::number_float_t>(NAN);
            CHECK(j2.is_number_float());
            json::number_float_t const f2{j2};
            CHECK(std::isnan(f2));
        }

        SECTION("infinity")
        {
            json const j1 = INFINITY;
            CHECK(j1.is_number_float());
            json::number_float_t const f1{j1};
            CHECK(!std::isfinite(f1));

            json const j2 = static_cast<json::number_float_t>(INFINITY);
            CHECK(j2.is_number_float());
            json::number_float_t const f2{j2};
            CHECK(!std::isfinite(f2));
        }
    }

#ifndef SKIP_TESTS_FOR_ENUM_SERIALIZATION
    SECTION("pull request #71 - handle enum type")
    {
        enum { t = 0, u = 102}; // NOLINT(cppcoreguidelines-use-enum-class)
        json j = json::array();
        j.push_back(t);

        // maybe this is not the place to test this?
        const json j2 = u;

        auto anon_enum_value = j2.get<decltype(u)>();
        CHECK(u == anon_enum_value);

        // check if the actual value was stored
        CHECK(j2 == 102);

        static_assert(std::is_same<decltype(anon_enum_value), decltype(u)>::value, "types must be the same");

        j.push_back(json::object(
        {
            {"game_type", t}
        }));
    }
#endif

    SECTION("issue #76 - dump() / parse() not idempotent")
    {
        // create JSON object
        json fields;
        fields["one"] = std::string("one");
        fields["two"] = std::string("two three");
        fields["three"] = std::string("three \"four\"");

        // create another JSON object by deserializing the serialization
        std::string const payload = fields.dump();
        json parsed_fields = json::parse(payload);

        // check individual fields to match both objects
        CHECK(parsed_fields["one"] == fields["one"]);
        CHECK(parsed_fields["two"] == fields["two"]);
        CHECK(parsed_fields["three"] == fields["three"]);

        // check individual fields to match original input
        CHECK(parsed_fields["one"] == std::string("one"));
        CHECK(parsed_fields["two"] == std::string("two three"));
        CHECK(parsed_fields["three"] == std::string("three \"four\""));

        // check equality of the objects
        CHECK(parsed_fields == fields);

        // check equality of the serialized objects
        CHECK(fields.dump() == parsed_fields.dump());

        // check everything in one line
        CHECK(fields == json::parse(fields.dump()));
    }

    SECTION("issue #82 - lexer::get_number return NAN")
    {
        const auto* const content = R"(
        {
            "Test":"Test1",
            "Number":100,
            "Foo":42.42
        })";

        std::stringstream ss;
        ss << content;
        json j;
        ss >> j;

        auto test = j["Test"].get<std::string>();
        CHECK(test == "Test1");
        const int number{j["Number"]};
        CHECK(number == 100);
        const float foo{j["Foo"]};
        CHECK(static_cast<double>(foo) == Approx(42.42));
    }

    SECTION("issue #89 - nonstandard integer type")
    {
        // create JSON class with nonstandard integer number type
        using custom_json =
            nlohmann::basic_json<std::map, std::vector, std::string, bool, int32_t, uint32_t, float>;
        custom_json j;
        j["int_1"] = 1;
        CHECK(j["int_1"] == 1);

        // tests for correct handling of non-standard integers that overflow the type selected by the user

        // unsigned integer object creation - expected to wrap and still be stored as an integer
        j = 4294967296U; // 2^32
        CHECK(static_cast<int>(j.type()) == static_cast<int>(custom_json::value_t::number_unsigned));
        CHECK(j.get<uint32_t>() == 0);  // Wrap

        // unsigned integer parsing - expected to overflow and be stored as a float
        j = custom_json::parse("4294967296"); // 2^32
        CHECK(static_cast<int>(j.type()) == static_cast<int>(custom_json::value_t::number_float));
        CHECK(j.get<float>() == 4294967296.0f);

        // integer object creation - expected to wrap and still be stored as an integer
        j = -2147483649LL; // -2^31-1
        CHECK(static_cast<int>(j.type()) == static_cast<int>(custom_json::value_t::number_integer));
        CHECK(j.get<int32_t>() == 2147483647);  // Wrap

        // integer parsing - expected to overflow and be stored as a float with rounding
        j = custom_json::parse("-2147483649"); // -2^31
        CHECK(static_cast<int>(j.type()) == static_cast<int>(custom_json::value_t::number_float));
        CHECK(j.get<float>() == -2147483650.0f);
    }

    SECTION("issue #93 reverse_iterator operator inheritance problem")
    {
        {
            json a = {1, 2, 3};
            json::reverse_iterator rit = a.rbegin();
            ++rit;
            CHECK(*rit == json(2));
            CHECK(rit.value() == json(2));
        }
        {
            json a = {1, 2, 3};
            json::reverse_iterator const rit = ++a.rbegin();
            CHECK(*rit == json(2));
            CHECK(rit.value() == json(2));
        }
        {
            json a = {1, 2, 3};
            json::reverse_iterator rit = a.rbegin();
            ++rit;
            json b = {0, 0, 0};
            std::transform(rit, a.rend(), b.rbegin(), [](json el)
            {
                return el;
            });
            CHECK(b == json({0, 1, 2}));
        }
        {
            json a = {1, 2, 3};
            json b = {0, 0, 0};
            std::transform(++a.rbegin(), a.rend(), b.rbegin(), [](json el)
            {
                return el;
            });
            CHECK(b == json({0, 1, 2}));
        }
    }

    SECTION("issue #100 - failed to iterator json object with reverse_iterator")
    {
        json config =
        {
            { "111", 111 },
            { "112", 112 },
            { "113", 113 }
        };

        std::stringstream ss;

        for (auto it = config.begin(); it != config.end(); ++it)
        {
            ss << it.key() << ": " << it.value() << '\n';
        }

        for (auto it = config.rbegin(); it != config.rend(); ++it)
        {
            ss << it.key() << ": " << it.value() << '\n';
        }

        CHECK(ss.str() == "111: 111\n112: 112\n113: 113\n113: 113\n112: 112\n111: 111\n");
    }

    SECTION("issue #101 - binary string causes numbers to be dumped as hex")
    {
        int64_t const number = 10;
        std::string const bytes{"\x00" "asdf\n", 6};
        json j;
        j["int64"] = number;
        j["binary string"] = bytes;
        // make sure the number is really printed as decimal "10" and not as
        // hexadecimal "a"
        CHECK(j.dump() == "{\"binary string\":\"\\u0000asdf\\n\",\"int64\":10}");
    }

    SECTION("issue #111 - subsequent unicode chars")
    {
        std::string const bytes{0x7, 0x7};
        json j;
        j["string"] = bytes;
        CHECK(j["string"] == "\u0007\u0007");
    }

#if JSON_USE_IMPLICIT_CONVERSIONS
    SECTION("issue #144 - implicit assignment to std::string fails")
    {
        json o = {{"name", "value"}};

        const std::string s1 = o["name"];
        CHECK(s1 == "value");

        std::string s2;
        s2 = o["name"];

        CHECK(s2 == "value");

        // improve coverage
        o["int"] = 1;
#if JSON_DIAGNOSTICS
        CHECK_THROWS_WITH_AS(s2 = o["int"], "[json.exception.type_error.302] (/int) type must be string, but is number", json::type_error);
#else
        CHECK_THROWS_WITH_AS(s2 = o["int"], "[json.exception.type_error.302] type must be string, but is number", json::type_error);
#endif
    }
#endif

    SECTION("issue #146 - character following a surrogate pair is skipped")
    {
        CHECK(json::parse("\"\\ud80c\\udc60abc\"").get<json::string_t>() == "\xf0\x93\x81\xa0\x61\x62\x63");
    }

    SECTION("issue #171 - Cannot index by key of type static constexpr const char*")
    {
        json j;

        // Non-const access with key as "char []"
        char array_key[] = "Key1"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
        CHECK_NOTHROW(j[array_key] = 1);
        CHECK(j[array_key] == json(1));

        // Non-const access with key as "const char[]"
        const char const_array_key[] = "Key2"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
        CHECK_NOTHROW(j[const_array_key] = 2);
        CHECK(j[const_array_key] == json(2));

        // Non-const access with key as "char *"
        char _ptr_key[] = "Key3"; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
        char* ptr_key = &_ptr_key[0]; // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
        CHECK_NOTHROW(j[ptr_key] = 3);
        CHECK(j[ptr_key] == json(3));

        // Non-const access with key as "const char *"
        const char* const_ptr_key = "Key4";
        CHECK_NOTHROW(j[const_ptr_key] = 4);
        CHECK(j[const_ptr_key] == json(4));

        // Non-const access with key as "static constexpr const char *"
        static constexpr const char* constexpr_ptr_key = "Key5";
        CHECK_NOTHROW(j[constexpr_ptr_key] = 5);
        CHECK(j[constexpr_ptr_key] == json(5));

        const json j_const = j;

        // Const access with key as "char []"
        CHECK(j_const[array_key] == json(1));

        // Const access with key as "const char[]"
        CHECK(j_const[const_array_key] == json(2));

        // Const access with key as "char *"
        CHECK(j_const[ptr_key] == json(3));

        // Const access with key as "const char *"
        CHECK(j_const[const_ptr_key] == json(4));

        // Const access with key as "static constexpr const char *"
        CHECK(j_const[constexpr_ptr_key] == json(5));
    }

    SECTION("issue #186 miloyip/nativejson-benchmark: floating-point parsing")
    {
        json j;

        j = json::parse("-0.0");
        CHECK(j.get<double>() == -0.0);

        j = json::parse("2.22507385850720113605740979670913197593481954635164564e-308");
        CHECK(j.get<double>() == 2.2250738585072009e-308);

        j = json::parse("0.999999999999999944488848768742172978818416595458984374");
        CHECK(j.get<double>() == 0.99999999999999989);

        j = json::parse("1.00000000000000011102230246251565404236316680908203126");
        CHECK(j.get<double>() == 1.00000000000000022);

        j = json::parse("7205759403792793199999e-5");
        CHECK(j.get<double>() == 72057594037927928.0);

        j = json::parse("922337203685477529599999e-5");
        CHECK(j.get<double>() == 9223372036854774784.0);

        j = json::parse("1014120480182583464902367222169599999e-5");
        CHECK(j.get<double>() == 10141204801825834086073718800384.0);

        j = json::parse("5708990770823839207320493820740630171355185151999e-3");
        CHECK(j.get<double>() == 5708990770823838890407843763683279797179383808.0);

        // create JSON class with nonstandard float number type

        // float
        nlohmann::basic_json<std::map, std::vector, std::string, bool, int32_t, uint32_t, float> const j_float =
            1.23e25f;
        CHECK(j_float.get<float>() == 1.23e25f);

        // double
        nlohmann::basic_json<std::map, std::vector, std::string, bool, int64_t, uint64_t, double> const j_double =
            1.23e35;
        CHECK(j_double.get<double>() == 1.23e35);

        // long double
        nlohmann::basic_json<std::map, std::vector, std::string, bool, int64_t, uint64_t, long double>
        const j_long_double = 1.23e45L;
        CHECK(j_long_double.get<long double>() == 1.23e45L);
    }

    SECTION("issue #228 - double values are serialized with commas as decimal points")
    {
        json const j1a = 2312.42;
        json const j1b = json::parse("2312.42");

        json const j2a = 2342e-2;
        //issue #230
        //json j2b = json::parse("2342e-2");

        json const j3a = 10E3;
        json const j3b = json::parse("10E3");
        json const j3c = json::parse("10e3");

        // class to create a locale that would use a comma for decimals
        class CommaDecimalSeparator : public std::numpunct<char>
        {
          protected:
            char do_decimal_point() const override
            {
                return ',';
            }

            char do_thousands_sep() const override
            {
                return '.';
            }

            std::string do_grouping() const override
            {
                return "\03";
            }
        };

        // change locale to mess with decimal points
        auto orig_locale = std::locale::global(std::locale(std::locale(), new CommaDecimalSeparator));

        CHECK(j1a.dump() == "2312.42");
        CHECK(j1b.dump() == "2312.42");

        // check if locale is properly reset
        std::stringstream ss;
        ss.imbue(std::locale(std::locale(), new CommaDecimalSeparator));
        ss << 4712.11;
        CHECK(ss.str() == "4.712,11");
        ss << j1a;
        CHECK(ss.str() == "4.712,112312.42");
        ss << 47.11;
        CHECK(ss.str() == "4.712,112312.4247,11");

        CHECK(j2a.dump() == "23.42");
        //issue #230
        //CHECK(j2b.dump() == "23.42");

        CHECK(j3a.dump() == "10000.0");
        CHECK(j3b.dump() == "10000.0");
        CHECK(j3c.dump() == "10000.0");
        //CHECK(j3b.dump() == "1E04"); // roundtrip error
        //CHECK(j3c.dump() == "1e04"); // roundtrip error

        std::locale::global(orig_locale);
    }

    SECTION("issue #378 - locale-independent num-to-str")
    {
        static_cast<void>(setlocale(LC_NUMERIC, "de_DE.UTF-8"));

        // verify that dumped correctly with '.' and no grouping
        const json j1 = 12345.67;
        CHECK(json(12345.67).dump() == "12345.67");
        static_cast<void>(setlocale(LC_NUMERIC, "C"));
    }

    SECTION("issue #379 - locale-independent str-to-num")
    {
        static_cast<void>(setlocale(LC_NUMERIC, "de_DE.UTF-8"));

        // verify that parsed correctly despite using strtod internally
        CHECK(json::parse("3.14").get<double>() == 3.14);

        // check a different code path
        CHECK(json::parse("1.000000000000000000000000000000000000000000000000000000000000000000000000").get<double>() == 1.0);
    }

    SECTION("issue #233 - Can't use basic_json::iterator as a base iterator for std::move_iterator")
    {
        json source = {"a", "b", "c"};
        json expected = {"a", "b"};
        json dest;

        std::copy_n(std::make_move_iterator(source.begin()), 2, std::back_inserter(dest));

        CHECK(dest == expected);
    }

    SECTION("issue #235 - ambiguous overload for 'push_back' and 'operator+='")
    {
        json data = {{"key", "value"}};
        data.push_back({"key2", "value2"});
        data += {"key3", "value3"};

        CHECK(data == json({{"key", "value"}, {"key2", "value2"}, {"key3", "value3"}}));
    }

    SECTION("issue #269 - diff generates incorrect patch when removing multiple array elements")
    {
        json const doc = R"( { "arr1": [1, 2, 3, 4] } )"_json;
        json expected = R"( { "arr1": [1, 2] } )"_json;

        // check roundtrip
        CHECK(doc.patch(json::diff(doc, expected)) == expected);
    }

    SECTION("issue #283 - value() does not work with _json_pointer types")
    {
        json j =
        {
            {"object", {{"key1", 1}, {"key2", 2}}},
        };

        const int at_integer{j.at("/object/key2"_json_pointer)};
        const int val_integer = j.value("/object/key2"_json_pointer, 0);

        CHECK(at_integer == val_integer);
    }

    SECTION("issue #304 - Unused variable warning")
    {
        // code triggered a "warning: unused variable" warning and is left
        // here to avoid the warning in the future
        json object;
        json const patch = json::array();
        object = object.patch(patch);
    }

    SECTION("issue #306 - Parsing fails without space at end of file")
    {
        for (const auto* filename :
                {
                    TEST_DATA_DIRECTORY "/regression/broken_file.json",
                    TEST_DATA_DIRECTORY "/regression/working_file.json"
                })
        {
            CAPTURE(filename)
            json j;
            std::ifstream f(filename);
            CHECK_NOTHROW(f >> j);
        }
    }

    SECTION("issue #310 - make json_benchmarks no longer working in 2.0.4")
    {
        for (const auto* filename :
                {
                    TEST_DATA_DIRECTORY "/regression/floats.json",
                    TEST_DATA_DIRECTORY "/regression/signed_ints.json",
                    TEST_DATA_DIRECTORY "/regression/unsigned_ints.json",
                    TEST_DATA_DIRECTORY "/regression/small_signed_ints.json"
                })
        {
            CAPTURE(filename)
            json j;
            std::ifstream f(filename);
            CHECK_NOTHROW(f >> j);
        }
    }

    SECTION("issue #323 - add nested object capabilities to pointers")
    {
        json j;
        j["/this/that/2"_json_pointer] = 27;
        CHECK(j == json({{"this", {{"that", {nullptr, nullptr, 27}}}}}));
    }

    SECTION("issue #329 - serialized value not always can be parsed")
    {
        json _;
        CHECK_THROWS_WITH_AS(_ = json::parse("22e2222"), "[json.exception.out_of_range.406] number overflow parsing '22e2222'", json::out_of_range&);
    }

    SECTION("issue #360 - Loss of precision when serializing <double>")
    {
        auto check_roundtrip = [](double number)
        {
            CAPTURE(number)

            json j = number;
            CHECK(j.is_number_float());

            std::stringstream ss;
            ss << j;

            CHECK_NOTHROW(ss >> j);
            CHECK(j.is_number_float());
            CHECK(j.get<json::number_float_t>() == number);
        };

        check_roundtrip(100000000000.1236);
        check_roundtrip((std::numeric_limits<json::number_float_t>::max)());

        // Some more numbers which fail to roundtrip when serialized with digits10 significand digits (instead of max_digits10)
        check_roundtrip(1.541888611948064e-17);
        check_roundtrip(5.418771028591015e-16);
        check_roundtrip(9.398685592608595e-15);
        check_roundtrip(8.826843952762347e-14);
        check_roundtrip(8.143291313475335e-13);
        check_roundtrip(4.851328172762508e-12);
        check_roundtrip(6.677850998084358e-11);
        check_roundtrip(3.995398518174525e-10);
        check_roundtrip(1.960452605645124e-9);
        check_roundtrip(3.551812586302883e-8);
        check_roundtrip(2.947988411689261e-7);
        check_roundtrip(8.210166748056192e-6);
        check_roundtrip(6.104889704266753e-5);
        check_roundtrip(0.0008629954631330876);
        check_roundtrip(0.004936993881051611);
        check_roundtrip(0.08309725102608073);
        check_roundtrip(0.5210494268499783);
        check_roundtrip(6.382927930939767);
        check_roundtrip(59.94947245358671);
        check_roundtrip(361.0838651266122);
        check_roundtrip(4678.354596181877);
        check_roundtrip(61412.17658956043);
        check_roundtrip(725696.0799057782);
        check_roundtrip(2811732.583399828);
        check_roundtrip(30178351.07533605);
        check_roundtrip(689684880.3235844);
        check_roundtrip(5714887673.555147);
        check_roundtrip(84652038821.18808);
        check_roundtrip(156510583431.7721);
        check_roundtrip(5938450569021.732);
        check_roundtrip(83623297654460.33);
        check_roundtrip(701466573254773.6);
        check_roundtrip(1369013370304513);
        check_roundtrip(96963648023094720); // NOLINT(bugprone-narrowing-conversions,cppcoreguidelines-narrowing-conversions)
        check_roundtrip(3.478237409280108e+17);
    }

    SECTION("issue #366 - json::parse on failed stream gets stuck")
    {
        std::ifstream f("file_not_found.json");
        json _;
        CHECK_THROWS_WITH_AS(_ = json::parse(f), "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
    }

    SECTION("issue #367 - calling stream at EOF")
    {
        std::stringstream ss;
        json j;
        ss << "123";
        CHECK_NOTHROW(ss >> j);

        // see https://github.com/nlohmann/json/issues/367#issuecomment-262841893:
        // ss is not at EOF; this yielded an error before the fix
        // (threw basic_string::append). No, it should just throw
        // a parse error because of the EOF.
        CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
    }

    SECTION("issue #367 - behavior of operator>> should more closely resemble that of built-in overloads")
    {
        SECTION("(empty)")
        {
            std::stringstream ss;
            json j;
            CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

        SECTION("(whitespace)")
        {
            std::stringstream ss;
            ss << "   ";
            json j;
            CHECK_THROWS_WITH_AS(ss >> j,
                                 "[json.exception.parse_error.101] parse error at line 1, column 4: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&);
        }

        SECTION("one value")
        {
            std::stringstream ss;
            ss << "111";
            json j;
            CHECK_NOTHROW(ss >> j);
            CHECK(j == 111);

            CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

        SECTION("one value + whitespace")
        {
            std::stringstream ss;
            ss << "222 \t\n";
            json j;
            CHECK_NOTHROW(ss >> j);
            CHECK(j == 222);

            CHECK_THROWS_WITH_AS(ss >> j,
                                 "[json.exception.parse_error.101] parse error at line 2, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&);
        }

        SECTION("whitespace + one value")
        {
            std::stringstream ss;
            ss << "\n\t 333";
            json j;
            CHECK_NOTHROW(ss >> j);
            CHECK(j == 333);

            CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

        SECTION("three values")
        {
            std::stringstream ss;
            ss << " 111 \n222\n \n  333";
            json j;
            CHECK_NOTHROW(ss >> j);
            CHECK(j == 111);
            CHECK_NOTHROW(ss >> j);
            CHECK(j == 222);
            CHECK_NOTHROW(ss >> j);
            CHECK(j == 333);

            CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

        SECTION("literals without whitespace")
        {
            std::stringstream ss;
            ss << "truefalsenull\"\"";
            json j;
            CHECK_NOTHROW(ss >> j);
            CHECK(j == true);
            CHECK_NOTHROW(ss >> j);
            CHECK(j == false);
            CHECK_NOTHROW(ss >> j);
            CHECK(j == nullptr);
            CHECK_NOTHROW(ss >> j);
            CHECK(j == "");

            CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

        SECTION("example from #529")
        {
            std::stringstream ss;
            ss << "{\n    \"one\"   : 1,\n    \"two\"   : 2\n}\n{\n    \"three\" : 3\n}";
            json j;
            CHECK_NOTHROW(ss >> j);
            CHECK(j == json({{"one", 1}, {"two", 2}}));
            CHECK_NOTHROW(ss >> j);
            CHECK(j == json({{"three", 3}}));

            CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

        SECTION("second example from #529")
        {
            std::string const str = "{\n\"one\"   : 1,\n\"two\"   : 2\n}\n{\n\"three\" : 3\n}";

            {
                std::ofstream file("test.json");
                file << str;
            }

            std::ifstream stream("test.json", std::ifstream::in);
            json val;

            size_t i = 0;
            while (stream.peek() != EOF)
            {
                CAPTURE(i)
                CHECK_NOTHROW(stream >> val);

                CHECK(i < 2);

                if (i == 0)
                {
                    CHECK(val == json({{"one", 1}, {"two", 2}}));
                }

                if (i == 1)
                {
                    CHECK(val == json({{"three", 3}}));
                }

                ++i;
            }

            static_cast<void>(std::remove("test.json"));
        }
    }

    SECTION("issue #389 - Integer-overflow (OSS-Fuzz issue 267)")
    {
        // original test case
        json const j1 = json::parse("-9223372036854775808");
        CHECK(j1.is_number_integer());
        CHECK(j1.get<json::number_integer_t>() == (std::numeric_limits<std::int64_t>::min)());

        // edge case (+1; still an integer)
        json const j2 = json::parse("-9223372036854775807");
        CHECK(j2.is_number_integer());
        CHECK(j2.get<json::number_integer_t>() == (std::numeric_limits<std::int64_t>::min)() + 1);

        // edge case (-1; overflow -> floats)
        json const j3 = json::parse("-9223372036854775809");
        CHECK(j3.is_number_float());
    }

    SECTION("issue #380 - bug in overflow detection when parsing integers")
    {
        json const j = json::parse("166020696663385964490");
        CHECK(j.is_number_float());
        CHECK(j.get<json::number_float_t>() == 166020696663385964490.0);
    }

    SECTION("issue #405 - Heap-buffer-overflow (OSS-Fuzz issue 342)")
    {
        // original test case
        std::vector<uint8_t> const vec {0x65, 0xf5, 0x0a, 0x48, 0x21};
        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec), "[json.exception.parse_error.110] parse error at byte 6: syntax error while parsing CBOR string: unexpected end of input", json::parse_error&);
    }

    SECTION("issue #407 - Heap-buffer-overflow (OSS-Fuzz issue 343)")
    {
        json _;

        // original test case: incomplete float64
        std::vector<uint8_t> const vec1 {0xcb, 0x8f, 0x0a};
        CHECK_THROWS_WITH_AS(_ = json::from_msgpack(vec1), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing MessagePack number: unexpected end of input", json::parse_error&);

        // related test case: incomplete float32
        std::vector<uint8_t> const vec2 {0xca, 0x8f, 0x0a};
        CHECK_THROWS_WITH_AS(_ = json::from_msgpack(vec2), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing MessagePack number: unexpected end of input", json::parse_error&);

        // related test case: incomplete Half-Precision Float (CBOR)
        std::vector<uint8_t> const vec3 {0xf9, 0x8f};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec3), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing CBOR number: unexpected end of input", json::parse_error&);

        // related test case: incomplete Single-Precision Float (CBOR)
        std::vector<uint8_t> const vec4 {0xfa, 0x8f, 0x0a};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec4), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing CBOR number: unexpected end of input", json::parse_error&);

        // related test case: incomplete Double-Precision Float (CBOR)
        std::vector<uint8_t> const vec5 {0xfb, 0x8f, 0x0a};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec5), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing CBOR number: unexpected end of input", json::parse_error&);
    }

    SECTION("issue #408 - Heap-buffer-overflow (OSS-Fuzz issue 344)")
    {
        json _;

        // original test case
        std::vector<uint8_t> const vec1 {0x87};
        CHECK_THROWS_WITH_AS(_ = json::from_msgpack(vec1), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing MessagePack string: unexpected end of input", json::parse_error&);

        // more test cases for MessagePack
        for (auto b :
                {
                    0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, // fixmap
                    0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, // fixarray
                    0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, // fixstr
                    0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf
                })
        {
            std::vector<uint8_t> const vec(1, static_cast<uint8_t>(b));
            CHECK_THROWS_AS(_ = json::from_msgpack(vec), json::parse_error&);
        }

        // more test cases for CBOR
        for (auto b :
                {
                    0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
                    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, // UTF-8 string
                    0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
                    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, // array
                    0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
                    0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7 // map
                })
        {
            std::vector<uint8_t> const vec(1, static_cast<uint8_t>(b));
            CHECK_THROWS_AS(_ = json::from_cbor(vec), json::parse_error&);
        }

        // special case: empty input
        std::vector<uint8_t> const vec2;
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec2), "[json.exception.parse_error.110] parse error at byte 1: syntax error while parsing CBOR value: unexpected end of input", json::parse_error&);
        CHECK_THROWS_WITH_AS(_ = json::from_msgpack(vec2), "[json.exception.parse_error.110] parse error at byte 1: syntax error while parsing MessagePack value: unexpected end of input", json::parse_error&);
    }

    SECTION("issue #411 - Heap-buffer-overflow (OSS-Fuzz issue 366)")
    {
        json _;

        // original test case: empty UTF-8 string (indefinite length)
        std::vector<uint8_t> const vec1 {0x7f};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec1), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing CBOR string: unexpected end of input", json::parse_error&);

        // related test case: empty array (indefinite length)
        std::vector<uint8_t> const vec2 {0x9f};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec2), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing CBOR value: unexpected end of input", json::parse_error&);

        // related test case: empty map (indefinite length)
        std::vector<uint8_t> const vec3 {0xbf};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec3), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing CBOR string: unexpected end of input", json::parse_error&);
    }

    SECTION("issue #412 - Heap-buffer-overflow (OSS-Fuzz issue 367)")
    {
        // original test case
        std::vector<uint8_t> const vec
        {
            0xab, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98,
            0x98, 0x98, 0x98, 0x98, 0x98, 0x00, 0x00, 0x00,
            0x60, 0xab, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98,
            0x98, 0x98, 0x98, 0x98, 0x98, 0x00, 0x00, 0x00,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0xa0, 0x9f,
            0x9f, 0x97, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60,
            0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60
        };

        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing CBOR object key: only string keys are supported, but found an array; last byte: 0x98", json::parse_error&);

        // related test case: nonempty UTF-8 string (indefinite length)
        std::vector<uint8_t> const vec1 {0x7f, 0x61, 0x61};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec1), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing CBOR string: unexpected end of input", json::parse_error&);

        // related test case: nonempty array (indefinite length)
        std::vector<uint8_t> const vec2 {0x9f, 0x01};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec2), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing CBOR value: unexpected end of input", json::parse_error&);

        // related test case: nonempty map (indefinite length)
        std::vector<uint8_t> const vec3 {0xbf, 0x61, 0x61, 0x01};
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec3), "[json.exception.parse_error.110] parse error at byte 5: syntax error while parsing CBOR string: unexpected end of input", json::parse_error&);
    }

    SECTION("issue #414 - compare with literal 0)")
    {
#define CHECK_TYPE(v) \
    CHECK((json(v) == (v)));\
    CHECK(((v) == json(v)));\
    CHECK_FALSE((json(v) != (v)));\
    CHECK_FALSE(((v) != json(v)));

        CHECK_TYPE(nullptr)
        CHECK_TYPE(0)
        CHECK_TYPE(0u)
        CHECK_TYPE(0L)
        CHECK_TYPE(0.0)
        CHECK_TYPE("") // NOLINT(readability-container-size-empty)

#undef CHECK_TYPE
    }

    SECTION("issue #416 - Use-of-uninitialized-value (OSS-Fuzz issue 377)")
    {
        // original test case
        std::vector<uint8_t> const vec1
        {
            0x94, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa,
            0x3a, 0x96, 0x96, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4,
            0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0x71,
            0xb4, 0xb4, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0x3a,
            0x96, 0x96, 0xb4, 0xb4, 0xfa, 0x94, 0x94, 0x61,
            0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0xfa
        };

        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec1), "[json.exception.parse_error.113] parse error at byte 13: syntax error while parsing CBOR object key: only string keys are supported, but found a map; last byte: 0xB4", json::parse_error&);

        // related test case: double-precision
        std::vector<uint8_t> const vec2
        {
            0x94, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa,
            0x3a, 0x96, 0x96, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4,
            0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0xb4, 0x71,
            0xb4, 0xb4, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0x3a,
            0x96, 0x96, 0xb4, 0xb4, 0xfa, 0x94, 0x94, 0x61,
            0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0xfb
        };
        CHECK_THROWS_WITH_AS(_ = json::from_cbor(vec2), "[json.exception.parse_error.113] parse error at byte 13: syntax error while parsing CBOR object key: only string keys are supported, but found a map; last byte: 0xB4", json::parse_error&);
    }

    SECTION("issue #452 - Heap-buffer-overflow (OSS-Fuzz issue 585)")
    {
        std::vector<uint8_t> const vec = {'-', '0', '1', '2', '2', '7', '4'};
        json _;
        CHECK_THROWS_AS(_ = json::parse(vec), json::parse_error&);
    }

    SECTION("issue #454 - doubles are printed as integers")
    {
        json j = R"({"bool_value":true,"double_value":2.0,"int_value":10,"level1":{"list_value":[3,"hi",false],"tmp":5.0},"string_value":"hello"})"_json;
        CHECK(j["double_value"].is_number_float());
    }

#if JSON_USE_IMPLICIT_CONVERSIONS
    SECTION("issue #464 - VS2017 implicit to std::string conversion fix")
    {
        const json v = "test";
        std::string test;
        test = v;
        CHECK(v == "test");
    }
#endif

    SECTION("issue #465 - roundtrip error while parsing 1000000000000000010E5")
    {
        json const j1 = json::parse("1000000000000000010E5");
        const std::string s1 = j1.dump();
        json const j2 = json::parse(s1);
        const std::string s2 = j2.dump();
        CHECK(s1 == s2);
    }

#if JSON_USE_IMPLICIT_CONVERSIONS
    SECTION("issue #473 - inconsistent behavior in conversion to array type")
    {
        json const j_array = {1, 2, 3, 4};
        json const j_number = 42;
        json const j_null = nullptr;

        SECTION("std::vector")
        {
            auto create = [](const json & j)
            {
                std::vector<int> const v = j;
            };

            CHECK_NOTHROW(create(j_array));
            CHECK_THROWS_WITH_AS(create(j_number), "[json.exception.type_error.302] type must be array, but is number", json::type_error&);
            CHECK_THROWS_WITH_AS(create(j_null), "[json.exception.type_error.302] type must be array, but is null", json::type_error&);
        }

        SECTION("std::list")
        {
            auto create = [](const json & j)
            {
                std::list<int> const v = j;
            };

            CHECK_NOTHROW(create(j_array));
            CHECK_THROWS_WITH_AS(create(j_number), "[json.exception.type_error.302] type must be array, but is number", json::type_error&);
            CHECK_THROWS_WITH_AS(create(j_null), "[json.exception.type_error.302] type must be array, but is null", json::type_error&);
        }

        SECTION("std::forward_list")
        {
            auto create = [](const json & j)
            {
                std::forward_list<int> const v = j;
            };

            CHECK_NOTHROW(create(j_array));
            CHECK_THROWS_WITH_AS(create(j_number), "[json.exception.type_error.302] type must be array, but is number", json::type_error&);
            CHECK_THROWS_WITH_AS(create(j_null), "[json.exception.type_error.302] type must be array, but is null", json::type_error&);
        }
    }
#endif

    SECTION("issue #486 - json::value_t can't be a map's key type in VC++ 2015")
    {
        // the code below must compile with MSVC
        std::map<json::value_t, std::string> jsonTypes ;
        jsonTypes[json::value_t::array] = "array";
    }

    SECTION("issue #494 - conversion from vector<bool> to json fails to build")
    {
        std::vector<bool> const boolVector = {false, true, false, false};
        json j;
        j["bool_vector"] = boolVector;

        CHECK(j["bool_vector"].dump() == "[false,true,false,false]");
    }

    SECTION("issue #504 - assertion error (OSS-Fuzz 856)")
    {
        std::vector<uint8_t> const vec1 = {0xf9, 0xff, 0xff, 0x4a, 0x3a, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01, 0x37, 0x02, 0x38};
        json const j1 = json::from_cbor(vec1, false);

        // step 2: round trip
        std::vector<uint8_t> vec2 = json::to_cbor(j1);

        // parse serialization
        json const j2 = json::from_cbor(vec2);

        // NaN is dumped to "null"
        CHECK(j2.is_number_float());
        CHECK(std::isnan(j2.get<json::number_float_t>()));
        CHECK(j2.dump() == "null");

        // check if serializations match
        CHECK(json::to_cbor(j2) == vec2);
    }

    SECTION("issue #512 - use of overloaded operator '<=' is ambiguous")
    {
        json j;
        j["a"] = 5;

        // json op scalar
        CHECK(j["a"] == 5);
        CHECK(j["a"] != 4);

        CHECK(j["a"] <= 7);
        CHECK(j["a"] <  7);
        CHECK(j["a"] >= 3);
        CHECK(j["a"] >  3);

        CHECK(!(j["a"] <= 4));
        CHECK(!(j["a"] <  4));
        CHECK(!(j["a"] >= 6));
        CHECK(!(j["a"] >  6));

        // scalar op json
        CHECK(5 == j["a"]);
        CHECK(4 != j["a"]);

        CHECK(7 >= j["a"]);
        CHECK(7 >  j["a"]);
        CHECK(3 <= j["a"]);
        CHECK(3 <  j["a"]);

        CHECK(!(4 >= j["a"]));
        CHECK(!(4 >  j["a"]));
        CHECK(!(6 <= j["a"]));
        CHECK(!(6 <  j["a"]));
    }

    SECTION("issue #575 - heap-buffer-overflow (OSS-Fuzz 1400)")
    {
        json _;
        std::vector<uint8_t> const vec = {'"', '\\', '"', 'X', '"', '"'};
        CHECK_THROWS_AS(_ = json::parse(vec), json::parse_error&);
    }

#if JSON_USE_IMPLICIT_CONVERSIONS
    SECTION("issue #600 - how does one convert a map in Json back to std::map?")
    {
        SECTION("example 1")
        {
            // create a map
            const std::map<std::string, int> m1 {{"key", 1}};

            // create and print a JSON from the map
            json const j = m1;

            // get the map out of JSON
            std::map<std::string, int> m2 = j;

            // make sure the roundtrip succeeds
            CHECK(m1 == m2);
        }

        SECTION("example 2")
        {
            // create a map
            const std::map<std::string, std::string> m1 {{"key", "val"}};

            // create and print a JSON from the map
            json const j = m1;

            // get the map out of JSON
            std::map<std::string, std::string> m2 = j;

            // make sure the roundtrip succeeds
            CHECK(m1 == m2);
        }
    }
#endif

    SECTION("issue #602 - BOM not skipped when using json:parse(iterator)")
    {
        std::string i = "\xef\xbb\xbf{\n   \"foo\": true\n}";
        json _;
        CHECK_NOTHROW(_ = json::parse(i.begin(), i.end()));
    }

#if JSON_USE_IMPLICIT_CONVERSIONS
    SECTION("issue #702 - conversion from valarray<double> to json fails to build")
    {
        SECTION("original example")
        {
            std::valarray<double> const v;
            nlohmann::json j;
            j["test"] = v;
        }

        SECTION("full example")
        {
            std::valarray<double> v = {1.2, 2.3, 3.4, 4.5};
            json j = v;
            std::valarray<double> vj = j;

            CHECK(j == json(vj));
            CHECK(v.size() == vj.size());
            for (size_t i = 0; i < v.size(); ++i)
            {
                CHECK(v[i] == vj[i]);
                CHECK(v[i] == j[i]);
            }

            CHECK_THROWS_WITH_AS(json().get<std::valarray<double>>(), "[json.exception.type_error.302] type must be array, but is null", json::type_error&);
        }
    }
#endif

    SECTION("issue #367 - Behavior of operator>> should more closely resemble that of built-in overloads.")
    {
        SECTION("example 1")
        {
            std::istringstream i1_2_3( R"({"first": "one" }{"second": "two"}3)" );
            json j1;
            json j2;
            json j3;
            i1_2_3 >> j1;
            i1_2_3 >> j2;
            i1_2_3 >> j3;

            auto m1 = j1.get<std::map<std::string, std::string>>();
            auto m2 = j2.get<std::map<std::string, std::string>>();
            const int i3{j3};

            CHECK( m1 == ( std::map<std::string, std::string> {{ "first",  "one" }} ));
            CHECK( m2 == ( std::map<std::string, std::string> {{ "second", "two" }} ));
            CHECK( i3 == 3 );
        }
    }

    SECTION("issue #714 - throw std::ios_base::failure exception when failbit set to true")
    {
        {
            std::ifstream is;
            is.exceptions(
                  is.exceptions()
                  | std::ios_base::failbit
                  | std::ios_base::badbit
              ); // handle different exceptions as 'file not found', 'permission denied'

            is.open(TEST_DATA_DIRECTORY "/regression/working_file.json");
            json _;
            CHECK_NOTHROW(_ = nlohmann::json::parse(is));
        }

        {
            std::ifstream is;
            is.exceptions(
                  is.exceptions()
                  | std::ios_base::failbit
                  | std::ios_base::badbit
              ); // handle different exceptions as 'file not found', 'permission denied'

            is.open(TEST_DATA_DIRECTORY "/json_nlohmann_tests/all_unicode.json.cbor",
                    std::ios_base::in | std::ios_base::binary);
            json _;
            CHECK_NOTHROW(_ = nlohmann::json::from_cbor(is));
        }
    }

    SECTION("issue #805 - copy constructor is used with std::initializer_list constructor.")
    {
        nocopy n;
        json j;
        j = {{"nocopy", n}};
        CHECK(j["nocopy"]["val"] == 0);
    }

    SECTION("issue #838 - incorrect parse error with binary data in keys")
    {
        std::array<uint8_t, 28> key1 = {{ 103, 92, 117, 48, 48, 48, 55, 92, 114, 215, 126, 214, 95, 92, 34, 174, 40, 71, 38, 174, 40, 71, 38, 223, 134, 247, 127, 0 }};
        std::string const key1_str(reinterpret_cast<char*>(key1.data()));
        json const j = key1_str;
        // dump() is nodiscard; the exception is thrown by dump() itself before it would return
        CHECK_THROWS_WITH_AS(utils::ignore_return_value(j.dump()), "[json.exception.type_error.316] invalid UTF-8 byte at index 10: 0x7E", json::type_error&);
    }

#if JSON_USE_IMPLICIT_CONVERSIONS
    SECTION("issue #843 - converting to array not working")
    {
        json j;
        std::array<int, 4> ar = {{1, 1, 1, 1}};
        j = ar;
        ar = j;
    }
#endif

    SECTION("issue #894 - invalid RFC6902 copy operation succeeds")
    {
        auto model = R"({
            "one": {
                "two": {
                    "three": "hello",
                    "four": 42
                }
            }
        })"_json;

        auto p1 = R"([{"op": "move",
                       "from": "/one/two/three",
                       "path": "/a/b/c"}])"_json;
#if JSON_DIAGNOSTIC_POSITIONS
        CHECK_THROWS_WITH_AS(model.patch(p1),
                             "[json.exception.out_of_range.403] (bytes 0-158) key 'a' not found", json::out_of_range&);
#else
        CHECK_THROWS_WITH_AS(model.patch(p1),
                             "[json.exception.out_of_range.403] key 'a' not found", json::out_of_range&);
#endif

        auto p2 = R"([{"op": "copy",
                       "from": "/one/two/three",
                       "path": "/a/b/c"}])"_json;
#if JSON_DIAGNOSTIC_POSITIONS
        CHECK_THROWS_WITH_AS(model.patch(p2),
                             "[json.exception.out_of_range.403] (bytes 0-158) key 'a' not found", json::out_of_range&);
#else
        CHECK_THROWS_WITH_AS(model.patch(p2),
                             "[json.exception.out_of_range.403] key 'a' not found", json::out_of_range&);
#endif
    }

    SECTION("issue #961 - incorrect parsing of indefinite length CBOR strings")
    {
        std::vector<uint8_t> const v_cbor =
        {
            0x7F,
            0x64,
            'a', 'b', 'c', 'd',
            0x63,
            '1', '2', '3',
            0xFF
        };
        const json j = json::from_cbor(v_cbor);
        CHECK(j == "abcd123");
    }

    SECTION("issue #962 - Timeout (OSS-Fuzz 6034)")
    {
        json _;
        std::vector<uint8_t> v_ubjson = {'[', '$', 'Z', '#', 'L', 0x78, 0x28, 0x00, 0x68, 0x28, 0x69, 0x69, 0x17};
        CHECK_THROWS_AS(_ = json::from_ubjson(v_ubjson), json::out_of_range&);
        //CHECK_THROWS_WITH(json::from_ubjson(v_ubjson),
        //                  "[json.exception.out_of_range.408] excessive array size: 8658170730974374167");

        v_ubjson[0] = '{';
        CHECK_THROWS_AS(_ = json::from_ubjson(v_ubjson), json::out_of_range&);
        //CHECK_THROWS_WITH(json::from_ubjson(v_ubjson),
        //                  "[json.exception.out_of_range.408] excessive object size: 8658170730974374167");
    }

    SECTION("issue #971 - Add a SAX parser - late bug")
    {
        // a JSON text
        const auto* text = R"(
    {
        "Image": {
            "Width":  800,
            "Height": 600,
            "Title":  "View from 15th Floor",
            "Thumbnail": {
                "Url":    "http://www.example.com/image/481989943",
                "Height": 125,
                "Width":  100
            },
            "Animated" : false,
            "IDs": [116, 943, 234, 38793]
        }
    }
    )";

        // define parser callback
        json::parser_callback_t const cb = [](int /*depth*/, json::parse_event_t event, json & parsed)
        {
            // skip object elements with key "Thumbnail"
            return !(event == json::parse_event_t::key && parsed == json("Thumbnail"));
        };

        // parse (with callback) and serialize JSON
        const json j_filtered = json::parse(text, cb);

        CHECK(j_filtered == R"({"Image":{"Animated":false,"Height":600,"IDs":[116,943,234,38793], "Title":"View from 15th Floor","Width":800}})"_json);
    }

    SECTION("issue #972 - Segmentation fault on G++ when trying to assign json string literal to custom json type")
    {
        // this assignment used to crash outright
        my_json const foo = R"([1, 2, 3])"_json;

        // fifo_map is the adapter the docs recommend for keeping object keys
        // in insertion order (see docs/mkdocs/docs/features/object_order.md
        // and docs/mkdocs/docs/features/types/template_parameters.md); check
        // that recommendation actually holds, including through erase() and
        // inserting a new key. The comparator is stateful, so this avoids
        // deep copies of "order" (see #1763, #5649).
        my_json order = my_json::parse(R"({"z":1,"a":2,"m":{"y":1,"b":2}})");
        CHECK(order.dump() == R"({"z":1,"a":2,"m":{"y":1,"b":2}})");

        order.erase("z");
        CHECK(order.dump() == R"({"a":2,"m":{"y":1,"b":2}})");

        order["new_key"] = 3;
        CHECK(order.dump() == R"({"a":2,"m":{"y":1,"b":2},"new_key":3})");
    }

    SECTION("issue #977 - Assigning between different json types")
    {
        foo_json lj = ns::foo{3};
        const ns::foo ff(lj);
        CHECK(lj.is_object());
        CHECK(lj.size() == 1);
        CHECK(lj["x"] == 3);
        CHECK(ff.x == 3);
        nlohmann::json const nj = lj;                // This line works as expected
    }
}

#if !defined(JSON_NOEXCEPTION)
TEST_CASE("regression tests, exceptions dependent")
{
    SECTION("issue #1340 - eof not set on exhausted input stream")
    {
        std::stringstream s("{}{}");
        json j;
        s >> j;
        s >> j;
        CHECK_THROWS_AS(s >> j, json::parse_error const&);
        CHECK(s.eof());
    }
}
#endif

/////////////////////////////////////////////////////////////////////
// for #1642
/////////////////////////////////////////////////////////////////////

// the code below fails with Clang on Windows, so we need to exclude it there
#if DOCTEST_CLANG && (defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__))
#else
template <typename T> class array {};
template <typename T> class object {};
template <typename T> class string {};
template <typename T> class number_integer {};
template <typename T> class number_unsigned {};
template <typename T> class number_float {};
#endif