json/tests/src/unit-bson.cpp

//     __ _____ _____ _____
//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
// |  |  |__   |  |  | | | |  version 3.11.3
// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2023 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT

#include "doctest_compatibility.h"

#include <nlohmann/json.hpp>
using nlohmann::json;

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

TEST_CASE("BSON")
{
    SECTION("individual values not supported")
    {
        SECTION("null")
        {
            json const j = nullptr;
            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is null", json::type_error&);
        }

        SECTION("boolean")
        {
            SECTION("true")
            {
                json const j = true;
                CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is boolean", json::type_error&);
            }

            SECTION("false")
            {
                json const j = false;
                CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is boolean", json::type_error&);
            }
        }

        SECTION("number")
        {
            json const j = 42;
            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is number", json::type_error&);
        }

        SECTION("float")
        {
            json const j = 4.2;
            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is number", json::type_error&);
        }

        SECTION("string")
        {
            json const j = "not supported";
            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is string", json::type_error&);
        }

        SECTION("array")
        {
            json const j = std::vector<int>{1, 2, 3, 4, 5, 6, 7};
            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is array", json::type_error&);
        }
    }

    SECTION("keys containing code-point U+0000 cannot be serialized to BSON")
    {
        json const j =
            {
                {std::string("en\0try", 6), true}};
#if JSON_DIAGNOSTICS
        CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.out_of_range.409] (/en) BSON key cannot contain code point U+0000 (at byte 2)", json::out_of_range&);
#else
        CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.out_of_range.409] BSON key cannot contain code point U+0000 (at byte 2)", json::out_of_range&);
#endif
    }

    SECTION("string length must be at least 1")
    {
        // from https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=11175
        std::vector<std::uint8_t> const v =
            {
                0x20,
                0x20,
                0x20,
                0x20,
                0x02,
                0x00,
                0x00,
                0x00,
                0x00,
                0x80};
        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_bson(v), "[json.exception.parse_error.112] parse error at byte 10: syntax error while parsing BSON string: string length must be at least 1, is -2147483648", json::parse_error&);
    }

    SECTION("objects")
    {
        SECTION("empty object")
        {
            json const j = json::object();
            std::vector<std::uint8_t> const expected =
                {
                    0x05,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    // no entries
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with bool")
        {
            json const j =
                {
                    {"entry", true}};

            std::vector<std::uint8_t> const expected =
                {
                    0x0D,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x08,  // entry: boolean
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x01,  // value = true
                    0x00   // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with bool")
        {
            json const j =
                {
                    {"entry", false}};

            std::vector<std::uint8_t> const expected =
                {
                    0x0D,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x08,  // entry: boolean
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x00,  // value = false
                    0x00   // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with double")
        {
            json const j =
                {
                    {"entry", 4.2}};

            std::vector<std::uint8_t> const expected =
                {
                    0x14,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x01,  /// entry: double
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0xcd,
                    0xcc,
                    0xcc,
                    0xcc,
                    0xcc,
                    0xcc,
                    0x10,
                    0x40,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with string")
        {
            json const j =
                {
                    {"entry", "bsonstr"}};

            std::vector<std::uint8_t> const expected =
                {
                    0x18,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x02,  /// entry: string (UTF-8)
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x08,
                    0x00,
                    0x00,
                    0x00,
                    'b',
                    's',
                    'o',
                    'n',
                    's',
                    't',
                    'r',
                    '\x00',
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with null member")
        {
            json const j =
                {
                    {"entry", nullptr}};

            std::vector<std::uint8_t> const expected =
                {
                    0x0C,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x0A,  /// entry: null
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with integer (32-bit) member")
        {
            json const j =
                {
                    {"entry", std::int32_t{0x12345678}}};

            std::vector<std::uint8_t> const expected =
                {
                    0x10,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x10,  /// entry: int32
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x78,
                    0x56,
                    0x34,
                    0x12,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with integer (64-bit) member")
        {
            json const j =
                {
                    {"entry", std::int64_t{0x1234567804030201}}};

            std::vector<std::uint8_t> const expected =
                {
                    0x14,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x12,  /// entry: int64
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x01,
                    0x02,
                    0x03,
                    0x04,
                    0x78,
                    0x56,
                    0x34,
                    0x12,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with negative integer (32-bit) member")
        {
            json const j =
                {
                    {"entry", std::int32_t{-1}}};

            std::vector<std::uint8_t> const expected =
                {
                    0x10,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x10,  /// entry: int32
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0xFF,
                    0xFF,
                    0xFF,
                    0xFF,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with negative integer (64-bit) member")
        {
            json const j =
                {
                    {"entry", std::int64_t{-1}}};

            std::vector<std::uint8_t> const expected =
                {
                    0x10,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x10,  /// entry: int32
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0xFF,
                    0xFF,
                    0xFF,
                    0xFF,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with unsigned integer (64-bit) member")
        {
            // directly encoding uint64 is not supported in bson (only for timestamp values)
            json const j =
                {
                    {"entry", std::uint64_t{0x1234567804030201}}};

            std::vector<std::uint8_t> const expected =
                {
                    0x14,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x12,  /// entry: int64
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x01,
                    0x02,
                    0x03,
                    0x04,
                    0x78,
                    0x56,
                    0x34,
                    0x12,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with small unsigned integer member")
        {
            json const j =
                {
                    {"entry", std::uint64_t{0x42}}};

            std::vector<std::uint8_t> const expected =
                {
                    0x10,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x10,  /// entry: int32
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',
                    0x42,
                    0x00,
                    0x00,
                    0x00,
                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with object member")
        {
            json const j =
                {
                    {"entry", json::object()}};

            std::vector<std::uint8_t> const expected =
                {
                    0x11,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x03,  /// entry: embedded document
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',

                    0x05,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    // no entries
                    0x00,  // end marker (embedded document)

                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with array member")
        {
            json const j =
                {
                    {"entry", json::array()}};

            std::vector<std::uint8_t> const expected =
                {
                    0x11,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x04,  /// entry: embedded document
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',

                    0x05,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    // no entries
                    0x00,  // end marker (embedded document)

                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with non-empty array member")
        {
            json const j =
                {
                    {"entry", json::array({1, 2, 3, 4, 5, 6, 7, 8})}};

            std::vector<std::uint8_t> const expected =
                {
                    0x49,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x04,  /// entry: embedded document
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',

                    0x3D,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x10,
                    '0',
                    0x00,
                    0x01,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '1',
                    0x00,
                    0x02,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '2',
                    0x00,
                    0x03,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '3',
                    0x00,
                    0x04,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '4',
                    0x00,
                    0x05,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '5',
                    0x00,
                    0x06,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '6',
                    0x00,
                    0x07,
                    0x00,
                    0x00,
                    0x00,
                    0x10,
                    '7',
                    0x00,
                    0x08,
                    0x00,
                    0x00,
                    0x00,
                    0x00,  // end marker (embedded document)

                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with binary member")
        {
            const size_t N = 10;
            const auto s = std::vector<std::uint8_t>(N, 'x');
            json const j =
                {
                    {"entry", json::binary(s, 0)}};

            std::vector<std::uint8_t> const expected =
                {
                    0x1B,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x05,  // entry: binary
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',

                    0x0A,
                    0x00,
                    0x00,
                    0x00,  // size of binary (little endian)
                    0x00,  // Generic binary subtype
                    0x78,
                    0x78,
                    0x78,
                    0x78,
                    0x78,
                    0x78,
                    0x78,
                    0x78,
                    0x78,
                    0x78,

                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("non-empty object with binary member with subtype")
        {
            // an MD5 hash
            const std::vector<std::uint8_t> md5hash = {0xd7, 0x7e, 0x27, 0x54, 0xbe, 0x12, 0x37, 0xfe, 0xd6, 0x0c, 0x33, 0x98, 0x30, 0x3b, 0x8d, 0xc4};
            json const j =
                {
                    {"entry", json::binary(md5hash, 5)}};

            std::vector<std::uint8_t> const expected =
                {
                    0x21,
                    0x00,
                    0x00,
                    0x00,  // size (little endian)
                    0x05,  // entry: binary
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    '\x00',

                    0x10,
                    0x00,
                    0x00,
                    0x00,  // size of binary (little endian)
                    0x05,  // MD5 binary subtype
                    0xd7,
                    0x7e,
                    0x27,
                    0x54,
                    0xbe,
                    0x12,
                    0x37,
                    0xfe,
                    0xd6,
                    0x0c,
                    0x33,
                    0x98,
                    0x30,
                    0x3b,
                    0x8d,
                    0xc4,

                    0x00  // end marker
                };

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }

        SECTION("Some more complex document")
        {
            // directly encoding uint64 is not supported in bson (only for timestamp values)
            json const j =
                {
                    {"double", 42.5},
                    {"entry", 4.2},
                    {"number", 12345},
                    {"object", {{"string", "value"}}}};

            std::vector<std::uint8_t> const expected =
                {
                    /*size */ 0x4f,
                    0x00,
                    0x00,
                    0x00,
                    /*entry*/ 0x01,
                    'd',
                    'o',
                    'u',
                    'b',
                    'l',
                    'e',
                    0x00,
                    0x00,
                    0x00,
                    0x00,
                    0x00,
                    0x00,
                    0x40,
                    0x45,
                    0x40,
                    /*entry*/ 0x01,
                    'e',
                    'n',
                    't',
                    'r',
                    'y',
                    0x00,
                    0xcd,
                    0xcc,
                    0xcc,
                    0xcc,
                    0xcc,
                    0xcc,
                    0x10,
                    0x40,
                    /*entry*/ 0x10,
                    'n',
                    'u',
                    'm',
                    'b',
                    'e',
                    'r',
                    0x00,
                    0x39,
                    0x30,
                    0x00,
                    0x00,
                    /*entry*/ 0x03,
                    'o',
                    'b',
                    'j',
                    'e',
                    'c',
                    't',
                    0x00,
                    /*entry: obj-size */ 0x17,
                    0x00,
                    0x00,
                    0x00,
                    /*entry: obj-entry*/ 0x02,
                    's',
                    't',
                    'r',
                    'i',
                    'n',
                    'g',
                    0x00,
                    0x06,
                    0x00,
                    0x00,
                    0x00,
                    'v',
                    'a',
                    'l',
                    'u',
                    'e',
                    0,
                    /*entry: obj-term.*/ 0x00,
                    /*obj-term*/ 0x00};

            const auto result = json::to_bson(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bson(result) == j);
            CHECK(json::from_bson(result, true, false) == j);
        }
    }

    SECTION("Examples from https://bsonspec.org/faq.html")
    {
        SECTION("Example 1")
        {
            std::vector<std::uint8_t> input = {0x16, 0x00, 0x00, 0x00, 0x02, 'h', 'e', 'l', 'l', 'o', 0x00, 0x06, 0x00, 0x00, 0x00, 'w', 'o', 'r', 'l', 'd', 0x00, 0x00};
            json parsed = json::from_bson(input);
            json expected = {{"hello", "world"}};
            CHECK(parsed == expected);
            auto dumped = json::to_bson(parsed);
            CHECK(dumped == input);
            CHECK(json::from_bson(dumped) == expected);
        }

        SECTION("Example 2")
        {
            std::vector<std::uint8_t> input = {0x31, 0x00, 0x00, 0x00, 0x04, 'B', 'S', 'O', 'N', 0x00, 0x26, 0x00, 0x00, 0x00, 0x02, 0x30, 0x00, 0x08, 0x00, 0x00, 0x00, 'a', 'w', 'e', 's', 'o', 'm', 'e', 0x00, 0x01, 0x31, 0x00, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x14, 0x40, 0x10, 0x32, 0x00, 0xc2, 0x07, 0x00, 0x00, 0x00, 0x00};
            json parsed = json::from_bson(input);
            json expected = {{"BSON", {"awesome", 5.05, 1986}}};
            CHECK(parsed == expected);
            auto dumped = json::to_bson(parsed);
            CHECK(dumped == input);
            CHECK(json::from_bson(dumped) == expected);
        }
    }
}

TEST_CASE("BSON input/output_adapters")
{
    json json_representation =
        {
            {"double", 42.5},
            {"entry", 4.2},
            {"number", 12345},
            {"object", {{"string", "value"}}}};

    std::vector<std::uint8_t> const bson_representation =
        {
            /*size */ 0x4f,
            0x00,
            0x00,
            0x00,
            /*entry*/ 0x01,
            'd',
            'o',
            'u',
            'b',
            'l',
            'e',
            0x00,
            0x00,
            0x00,
            0x00,
            0x00,
            0x00,
            0x40,
            0x45,
            0x40,
            /*entry*/ 0x01,
            'e',
            'n',
            't',
            'r',
            'y',
            0x00,
            0xcd,
            0xcc,
            0xcc,
            0xcc,
            0xcc,
            0xcc,
            0x10,
            0x40,
            /*entry*/ 0x10,
            'n',
            'u',
            'm',
            'b',
            'e',
            'r',
            0x00,
            0x39,
            0x30,
            0x00,
            0x00,
            /*entry*/ 0x03,
            'o',
            'b',
            'j',
            'e',
            'c',
            't',
            0x00,
            /*entry: obj-size */ 0x17,
            0x00,
            0x00,
            0x00,
            /*entry: obj-entry*/ 0x02,
            's',
            't',
            'r',
            'i',
            'n',
            'g',
            0x00,
            0x06,
            0x00,
            0x00,
            0x00,
            'v',
            'a',
            'l',
            'u',
            'e',
            0,
            /*entry: obj-term.*/ 0x00,
            /*obj-term*/ 0x00};

    json j2;
    CHECK_NOTHROW(j2 = json::from_bson(bson_representation));

    // compare parsed JSON values
    CHECK(json_representation == j2);

    SECTION("roundtrips")
    {
        SECTION("std::ostringstream")
        {
            std::basic_ostringstream<std::uint8_t> ss;
            json::to_bson(json_representation, ss);
            json j3 = json::from_bson(ss.str());
            CHECK(json_representation == j3);
        }

        SECTION("std::string")
        {
            std::string s;
            json::to_bson(json_representation, s);
            json j3 = json::from_bson(s);
            CHECK(json_representation == j3);
        }

        SECTION("std::vector")
        {
            std::vector<std::uint8_t> v;
            json::to_bson(json_representation, v);
            json j3 = json::from_bson(v);
            CHECK(json_representation == j3);
        }
    }
}

namespace {
class SaxCountdown
{
  public:
    explicit SaxCountdown(const int count)
      : events_left(count)
    {}

    bool null()
    {
        return events_left-- > 0;
    }

    bool boolean(bool /*unused*/)
    {
        return events_left-- > 0;
    }

    bool number_integer(json::number_integer_t /*unused*/)
    {
        return events_left-- > 0;
    }

    bool number_unsigned(json::number_unsigned_t /*unused*/)
    {
        return events_left-- > 0;
    }

    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
    {
        return events_left-- > 0;
    }

    bool string(std::string& /*unused*/)
    {
        return events_left-- > 0;
    }

    bool binary(std::vector<std::uint8_t>& /*unused*/)
    {
        return events_left-- > 0;
    }

    bool start_object(std::size_t /*unused*/)
    {
        return events_left-- > 0;
    }

    bool key(std::string& /*unused*/)
    {
        return events_left-- > 0;
    }

    bool end_object()
    {
        return events_left-- > 0;
    }

    bool start_array(std::size_t /*unused*/)
    {
        return events_left-- > 0;
    }

    bool end_array()
    {
        return events_left-- > 0;
    }

    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/)  // NOLINT(readability-convert-member-functions-to-static)
    {
        return false;
    }

  private:
    int events_left = 0;
};
}  // namespace

TEST_CASE("Incomplete BSON Input")
{
    SECTION("Incomplete BSON Input 1")
    {
        std::vector<std::uint8_t> const incomplete_bson =
            {
                0x0D,
                0x00,
                0x00,
                0x00,  // size (little endian)
                0x08,  // entry: boolean
                'e',
                'n',
                't'  // unexpected EOF
            };

        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_bson(incomplete_bson), "[json.exception.parse_error.110] parse error at byte 9: syntax error while parsing BSON cstring: unexpected end of input", json::parse_error&);

        CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());

        SaxCountdown scp(0);
        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
    }

    SECTION("Incomplete BSON Input 2")
    {
        std::vector<std::uint8_t> const incomplete_bson =
            {
                0x0D,
                0x00,
                0x00,
                0x00,  // size (little endian)
                0x08,  // entry: boolean, unexpected EOF
            };

        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_bson(incomplete_bson), "[json.exception.parse_error.110] parse error at byte 6: syntax error while parsing BSON cstring: unexpected end of input", json::parse_error&);
        CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());

        SaxCountdown scp(0);
        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
    }

    SECTION("Incomplete BSON Input 3")
    {
        std::vector<std::uint8_t> const incomplete_bson =
            {
                0x41,
                0x00,
                0x00,
                0x00,  // size (little endian)
                0x04,  /// entry: embedded document
                'e',
                'n',
                't',
                'r',
                'y',
                '\x00',

                0x35,
                0x00,
                0x00,
                0x00,  // size (little endian)
                0x10,
                0x00,
                0x01,
                0x00,
                0x00,
                0x00,
                0x10,
                0x00,
                0x02,
                0x00,
                0x00,
                0x00
                // missing input data...
            };

        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_bson(incomplete_bson), "[json.exception.parse_error.110] parse error at byte 28: syntax error while parsing BSON element list: unexpected end of input", json::parse_error&);
        CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());

        SaxCountdown scp(1);
        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
    }

    SECTION("Incomplete BSON Input 4")
    {
        std::vector<std::uint8_t> const incomplete_bson =
            {
                0x0D,
                0x00,  // size (incomplete), unexpected EOF
            };

        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_bson(incomplete_bson), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing BSON number: unexpected end of input", json::parse_error&);
        CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());

        SaxCountdown scp(0);
        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
    }

    SECTION("Improve coverage")
    {
        SECTION("key")
        {
            json const j = {{"key", "value"}};
            auto bson_vec = json::to_bson(j);
            SaxCountdown scp(2);
            CHECK(!json::sax_parse(bson_vec, &scp, json::input_format_t::bson));
        }

        SECTION("array")
        {
            json const j =
                {
                    {"entry", json::array()}};
            auto bson_vec = json::to_bson(j);
            SaxCountdown scp(2);
            CHECK(!json::sax_parse(bson_vec, &scp, json::input_format_t::bson));
        }
    }
}

TEST_CASE("Negative size of binary value")
{
    // invalid BSON: the size of the binary value is -1
    std::vector<std::uint8_t> const input =
        {
            0x21,
            0x00,
            0x00,
            0x00,  // size (little endian)
            0x05,  // entry: binary
            'e',
            'n',
            't',
            'r',
            'y',
            '\x00',

            0xFF,
            0xFF,
            0xFF,
            0xFF,  // size of binary (little endian)
            0x05,  // MD5 binary subtype
            0xd7,
            0x7e,
            0x27,
            0x54,
            0xbe,
            0x12,
            0x37,
            0xfe,
            0xd6,
            0x0c,
            0x33,
            0x98,
            0x30,
            0x3b,
            0x8d,
            0xc4,

            0x00  // end marker
        };
    json _;
    CHECK_THROWS_WITH_AS(_ = json::from_bson(input), "[json.exception.parse_error.112] parse error at byte 15: syntax error while parsing BSON binary: byte array length cannot be negative, is -1", json::parse_error);
}

TEST_CASE("Unsupported BSON input")
{
    std::vector<std::uint8_t> const bson =
        {
            0x0C,
            0x00,
            0x00,
            0x00,  // size (little endian)
            0xFF,  // entry type: Min key (not supported yet)
            'e',
            'n',
            't',
            'r',
            'y',
            '\x00',
            0x00  // end marker
        };

    json _;
    CHECK_THROWS_WITH_AS(_ = json::from_bson(bson), "[json.exception.parse_error.114] parse error at byte 5: Unsupported BSON record type 0xFF", json::parse_error&);
    CHECK(json::from_bson(bson, true, false).is_discarded());

    SaxCountdown scp(0);
    CHECK(!json::sax_parse(bson, &scp, json::input_format_t::bson));
}

TEST_CASE("BSON numerical data")
{
    SECTION("number")
    {
        SECTION("signed")
        {
            SECTION("std::int64_t: INT64_MIN .. INT32_MIN-1")
            {
                std::vector<int64_t> const numbers{
                    (std::numeric_limits<int64_t>::min)(),
                    -1000000000000000000LL,
                    -100000000000000000LL,
                    -10000000000000000LL,
                    -1000000000000000LL,
                    -100000000000000LL,
                    -10000000000000LL,
                    -1000000000000LL,
                    -100000000000LL,
                    -10000000000LL,
                    static_cast<std::int64_t>((std::numeric_limits<std::int32_t>::min)()) - 1,
                };

                for (const auto i : numbers)
                {
                    CAPTURE(i)

                    json const j =
                        {
                            {"entry", i}};
                    CHECK(j.at("entry").is_number_integer());

                    std::uint64_t const iu = *reinterpret_cast<const std::uint64_t*>(&i);
                    std::vector<std::uint8_t> const expected_bson =
                        {
                            0x14u,
                            0x00u,
                            0x00u,
                            0x00u,  // size (little endian)
                            0x12u,  /// entry: int64
                            'e',
                            'n',
                            't',
                            'r',
                            'y',
                            '\x00',
                            static_cast<std::uint8_t>((iu >> (8u * 0u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 1u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 2u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 3u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 4u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 5u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 6u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 7u)) & 0xffu),
                            0x00u  // end marker
                        };

                    const auto bson = json::to_bson(j);
                    CHECK(bson == expected_bson);

                    auto j_roundtrip = json::from_bson(bson);

                    CHECK(j_roundtrip.at("entry").is_number_integer());
                    CHECK(j_roundtrip == j);
                    CHECK(json::from_bson(bson, true, false) == j);
                }
            }

            SECTION("signed std::int32_t: INT32_MIN .. INT32_MAX")
            {
                std::vector<int32_t> const numbers{
                    (std::numeric_limits<int32_t>::min)(),
                    -2147483647L,
                    -1000000000L,
                    -100000000L,
                    -10000000L,
                    -1000000L,
                    -100000L,
                    -10000L,
                    -1000L,
                    -100L,
                    -10L,
                    -1L,
                    0L,
                    1L,
                    10L,
                    100L,
                    1000L,
                    10000L,
                    100000L,
                    1000000L,
                    10000000L,
                    100000000L,
                    1000000000L,
                    2147483646L,
                    (std::numeric_limits<int32_t>::max)()};

                for (const auto i : numbers)
                {
                    CAPTURE(i)

                    json const j =
                        {
                            {"entry", i}};
                    CHECK(j.at("entry").is_number_integer());

                    std::uint32_t const iu = *reinterpret_cast<const std::uint32_t*>(&i);
                    std::vector<std::uint8_t> const expected_bson =
                        {
                            0x10u,
                            0x00u,
                            0x00u,
                            0x00u,  // size (little endian)
                            0x10u,  /// entry: int32
                            'e',
                            'n',
                            't',
                            'r',
                            'y',
                            '\x00',
                            static_cast<std::uint8_t>((iu >> (8u * 0u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 1u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 2u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 3u)) & 0xffu),
                            0x00u  // end marker
                        };

                    const auto bson = json::to_bson(j);
                    CHECK(bson == expected_bson);

                    auto j_roundtrip = json::from_bson(bson);

                    CHECK(j_roundtrip.at("entry").is_number_integer());
                    CHECK(j_roundtrip == j);
                    CHECK(json::from_bson(bson, true, false) == j);
                }
            }

            SECTION("signed std::int64_t: INT32_MAX+1 .. INT64_MAX")
            {
                std::vector<int64_t> const numbers{
                    (std::numeric_limits<int64_t>::max)(),
                    1000000000000000000LL,
                    100000000000000000LL,
                    10000000000000000LL,
                    1000000000000000LL,
                    100000000000000LL,
                    10000000000000LL,
                    1000000000000LL,
                    100000000000LL,
                    10000000000LL,
                    static_cast<std::int64_t>((std::numeric_limits<int32_t>::max)()) + 1,
                };

                for (const auto i : numbers)
                {
                    CAPTURE(i)

                    json const j =
                        {
                            {"entry", i}};
                    CHECK(j.at("entry").is_number_integer());

                    std::uint64_t const iu = *reinterpret_cast<const std::uint64_t*>(&i);
                    std::vector<std::uint8_t> const expected_bson =
                        {
                            0x14u,
                            0x00u,
                            0x00u,
                            0x00u,  // size (little endian)
                            0x12u,  /// entry: int64
                            'e',
                            'n',
                            't',
                            'r',
                            'y',
                            '\x00',
                            static_cast<std::uint8_t>((iu >> (8u * 0u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 1u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 2u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 3u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 4u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 5u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 6u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 7u)) & 0xffu),
                            0x00u  // end marker
                        };

                    const auto bson = json::to_bson(j);
                    CHECK(bson == expected_bson);

                    auto j_roundtrip = json::from_bson(bson);

                    CHECK(j_roundtrip.at("entry").is_number_integer());
                    CHECK(j_roundtrip == j);
                    CHECK(json::from_bson(bson, true, false) == j);
                }
            }
        }

        SECTION("unsigned")
        {
            SECTION("unsigned std::uint64_t: 0 .. INT32_MAX")
            {
                std::vector<std::uint64_t> const numbers{
                    0ULL,
                    1ULL,
                    10ULL,
                    100ULL,
                    1000ULL,
                    10000ULL,
                    100000ULL,
                    1000000ULL,
                    10000000ULL,
                    100000000ULL,
                    1000000000ULL,
                    2147483646ULL,
                    static_cast<std::uint64_t>((std::numeric_limits<int32_t>::max)())};

                for (const auto i : numbers)
                {
                    CAPTURE(i)

                    json const j =
                        {
                            {"entry", i}};

                    auto iu = i;
                    std::vector<std::uint8_t> const expected_bson =
                        {
                            0x10u,
                            0x00u,
                            0x00u,
                            0x00u,  // size (little endian)
                            0x10u,  /// entry: int32
                            'e',
                            'n',
                            't',
                            'r',
                            'y',
                            '\x00',
                            static_cast<std::uint8_t>((iu >> (8u * 0u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 1u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 2u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 3u)) & 0xffu),
                            0x00u  // end marker
                        };

                    const auto bson = json::to_bson(j);
                    CHECK(bson == expected_bson);

                    auto j_roundtrip = json::from_bson(bson);

                    CHECK(j.at("entry").is_number_unsigned());
                    CHECK(j_roundtrip.at("entry").is_number_integer());
                    CHECK(j_roundtrip == j);
                    CHECK(json::from_bson(bson, true, false) == j);
                }
            }

            SECTION("unsigned std::uint64_t: INT32_MAX+1 .. INT64_MAX")
            {
                std::vector<std::uint64_t> const numbers{
                    static_cast<std::uint64_t>((std::numeric_limits<std::int32_t>::max)()) + 1,
                    4000000000ULL,
                    static_cast<std::uint64_t>((std::numeric_limits<std::uint32_t>::max)()),
                    10000000000ULL,
                    100000000000ULL,
                    1000000000000ULL,
                    10000000000000ULL,
                    100000000000000ULL,
                    1000000000000000ULL,
                    10000000000000000ULL,
                    100000000000000000ULL,
                    1000000000000000000ULL,
                    static_cast<std::uint64_t>((std::numeric_limits<std::int64_t>::max)()),
                };

                for (const auto i : numbers)
                {
                    CAPTURE(i)

                    json const j =
                        {
                            {"entry", i}};

                    auto iu = i;
                    std::vector<std::uint8_t> const expected_bson =
                        {
                            0x14u,
                            0x00u,
                            0x00u,
                            0x00u,  // size (little endian)
                            0x12u,  /// entry: int64
                            'e',
                            'n',
                            't',
                            'r',
                            'y',
                            '\x00',
                            static_cast<std::uint8_t>((iu >> (8u * 0u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 1u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 2u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 3u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 4u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 5u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 6u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 7u)) & 0xffu),
                            0x00u  // end marker
                        };

                    const auto bson = json::to_bson(j);
                    CHECK(bson == expected_bson);

                    auto j_roundtrip = json::from_bson(bson);

                    CHECK(j.at("entry").is_number_unsigned());
                    CHECK(j_roundtrip.at("entry").is_number_integer());
                    CHECK(j_roundtrip == j);
                    CHECK(json::from_bson(bson, true, false) == j);
                }
            }

            SECTION("unsigned std::uint64_t: INT64_MAX+1 .. UINT64_MAX")
            {
                std::vector<std::uint64_t> const numbers{
                    static_cast<std::uint64_t>((std::numeric_limits<std::int64_t>::max)()) + 1ULL,
                    10000000000000000000ULL,
                    18000000000000000000ULL,
                    (std::numeric_limits<std::uint64_t>::max)() - 1ULL,
                    (std::numeric_limits<std::uint64_t>::max)(),
                };

                for (const auto i : numbers)
                {
                    CAPTURE(i)

                    json const j =
                        {
                            {"entry", i}};

                    auto iu = i;
                    std::vector<std::uint8_t> const expected_bson =
                        {
                            0x14u,
                            0x00u,
                            0x00u,
                            0x00u,  // size (little endian)
                            0x12u,  /// entry: int64
                            'e',
                            'n',
                            't',
                            'r',
                            'y',
                            '\x00',
                            static_cast<std::uint8_t>((iu >> (8u * 0u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 1u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 2u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 3u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 4u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 5u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 6u)) & 0xffu),
                            static_cast<std::uint8_t>((iu >> (8u * 7u)) & 0xffu),
                            0x00u  // end marker
                        };

                    CHECK_THROWS_AS(json::to_bson(j), json::out_of_range&);
#if JSON_DIAGNOSTICS
                    CHECK_THROWS_WITH_STD_STR(json::to_bson(j), "[json.exception.out_of_range.407] (/entry) integer number " + std::to_string(i) + " cannot be represented by BSON as it does not fit int64");
#else
                    CHECK_THROWS_WITH_STD_STR(json::to_bson(j), "[json.exception.out_of_range.407] integer number " + std::to_string(i) + " cannot be represented by BSON as it does not fit int64");
#endif
                }
            }
        }
    }
}

TEST_CASE("BSON roundtrips" * doctest::skip())
{
    SECTION("reference files")
    {
        for (const std::string filename :
             {
                 TEST_DATA_DIRECTORY "/json.org/1.json",
                 TEST_DATA_DIRECTORY "/json.org/2.json",
                 TEST_DATA_DIRECTORY "/json.org/3.json",
                 TEST_DATA_DIRECTORY "/json.org/4.json",
                 TEST_DATA_DIRECTORY "/json.org/5.json"})
        {
            CAPTURE(filename)

            {
                INFO_WITH_TEMP(filename + ": std::vector<std::uint8_t>");
                // parse JSON file
                std::ifstream f_json(filename);
                json j1 = json::parse(f_json);

                // parse BSON file
                auto packed = utils::read_binary_file(filename + ".bson");
                json j2;
                CHECK_NOTHROW(j2 = json::from_bson(packed));

                // compare parsed JSON values
                CHECK(j1 == j2);
            }

            {
                INFO_WITH_TEMP(filename + ": std::ifstream");
                // parse JSON file
                std::ifstream f_json(filename);
                json j1 = json::parse(f_json);

                // parse BSON file
                std::ifstream f_bson(filename + ".bson", std::ios::binary);
                json j2;
                CHECK_NOTHROW(j2 = json::from_bson(f_bson));

                // compare parsed JSON values
                CHECK(j1 == j2);
            }

            {
                INFO_WITH_TEMP(filename + ": uint8_t* and size");
                // parse JSON file
                std::ifstream f_json(filename);
                json j1 = json::parse(f_json);

                // parse BSON file
                auto packed = utils::read_binary_file(filename + ".bson");
                json j2;
                CHECK_NOTHROW(j2 = json::from_bson({packed.data(), packed.size()}));

                // compare parsed JSON values
                CHECK(j1 == j2);
            }

            {
                INFO_WITH_TEMP(filename + ": output to output adapters");
                // parse JSON file
                std::ifstream f_json(filename);
                json const j1 = json::parse(f_json);

                // parse BSON file
                auto packed = utils::read_binary_file(filename + ".bson");

                {
                    INFO_WITH_TEMP(filename + ": output adapters: std::vector<std::uint8_t>");
                    std::vector<std::uint8_t> vec;
                    json::to_bson(j1, vec);

                    if (vec != packed)
                    {
                        // the exact serializations may differ due to the order of
                        // object keys; in these cases, just compare whether both
                        // serializations create the same JSON value
                        CHECK(json::from_bson(vec) == json::from_bson(packed));
                    }
                }
            }
        }
    }
}