tests/src/unit-hash.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 json = nlohmann::json;
using ordered_json = nlohmann::ordered_json;

#include <set>

TEST_CASE("hash<nlohmann::json>")
{
    // Collect hashes for different JSON values and make sure that they are distinct
    // We cannot compare against fixed values, because the implementation of
    // std::hash may differ between compilers.

    std::set<std::size_t> hashes;

    // null
    hashes.insert(std::hash<json>{}(json(nullptr)));

    // boolean
    hashes.insert(std::hash<json>{}(json(true)));
    hashes.insert(std::hash<json>{}(json(false)));

    // string
    hashes.insert(std::hash<json>{}(json("")));
    hashes.insert(std::hash<json>{}(json("foo")));

    // number
    hashes.insert(std::hash<json>{}(json(0)));
    hashes.insert(std::hash<json>{}(json(static_cast<unsigned>(0))));

    hashes.insert(std::hash<json>{}(json(-1)));
    hashes.insert(std::hash<json>{}(json(0.0)));
    hashes.insert(std::hash<json>{}(json(42.23)));

    // array
    hashes.insert(std::hash<json>{}(json::array()));
    hashes.insert(std::hash<json>{}(json::array({ 1, 2, 3 })));

    // object
    hashes.insert(std::hash<json>{}(json::object()));
    hashes.insert(std::hash<json>{}(json::object({ { "foo", "bar" } })));

    // binary
    hashes.insert(std::hash<json>{}(json::binary({})));
    hashes.insert(std::hash<json>{}(json::binary({}, 0)));
    hashes.insert(std::hash<json>{}(json::binary({}, 42)));
    hashes.insert(std::hash<json>{}(json::binary({ 1, 2, 3 })));
    hashes.insert(std::hash<json>{}(json::binary({ 1, 2, 3 }, 0)));
    hashes.insert(std::hash<json>{}(json::binary({ 1, 2, 3 }, 42)));

    // discarded
    hashes.insert(std::hash<json>{}(json(json::value_t::discarded)));

    CHECK(hashes.size() == 21);
}

TEST_CASE("hash<nlohmann::ordered_json>")
{
    // Collect hashes for different JSON values and make sure that they are distinct
    // We cannot compare against fixed values, because the implementation of
    // std::hash may differ between compilers.

    std::set<std::size_t> hashes;

    // null
    hashes.insert(std::hash<ordered_json>{}(ordered_json(nullptr)));

    // boolean
    hashes.insert(std::hash<ordered_json>{}(ordered_json(true)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json(false)));

    // string
    hashes.insert(std::hash<ordered_json>{}(ordered_json("")));
    hashes.insert(std::hash<ordered_json>{}(ordered_json("foo")));

    // number
    hashes.insert(std::hash<ordered_json>{}(ordered_json(0)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json(static_cast<unsigned>(0))));

    hashes.insert(std::hash<ordered_json>{}(ordered_json(-1)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json(0.0)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json(42.23)));

    // array
    hashes.insert(std::hash<ordered_json>{}(ordered_json::array()));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::array({ 1, 2, 3 })));

    // object
    hashes.insert(std::hash<ordered_json>{}(ordered_json::object()));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::object({ { "foo", "bar" } })));

    // binary
    hashes.insert(std::hash<ordered_json>{}(ordered_json::binary({})));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::binary({}, 0)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::binary({}, 42)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::binary({ 1, 2, 3 })));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::binary({ 1, 2, 3 }, 0)));
    hashes.insert(std::hash<ordered_json>{}(ordered_json::binary({ 1, 2, 3 }, 42)));

    // discarded
    hashes.insert(std::hash<ordered_json>{}(ordered_json(ordered_json::value_t::discarded)));

    CHECK(hashes.size() == 21);
}