json/test/src/unit-fancy-serialization.cpp

/*
    __ _____ _____ _____
 __|  |   __|     |   | |  JSON for Modern C++ (test suite)
|  |  |__   |  |  | | | |  version 3.1.2
|_____|_____|_____|_|___|  https://github.com/nlohmann/json

Licensed under the MIT License <http://opensource.org/licenses/MIT>.
SPDX-License-Identifier: MIT
Copyright (c) 2018 Evan Driscoll <evaned@gmail.com>

Permission is hereby  granted, free of charge, to any  person obtaining a copy
of this software and associated  documentation files (the "Software"), to deal
in the Software  without restriction, including without  limitation the rights
to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include "catch.hpp"

#include <nlohmann/json.hpp>

using nlohmann::json;
using nlohmann::fancy_dump;
using nlohmann::fancy_serializer_style;

std::string fancy_to_string(json j, fancy_serializer_style style = fancy_serializer_style())
{
    std::stringstream ss;
    fancy_dump(ss, j, style);
    return ss.str();
}

TEST_CASE("serialization")
{
    SECTION("primitives")
    {
        SECTION("null")
        {
            auto str = fancy_to_string({});
            CHECK(str == "null");
        }

        SECTION("true")
        {
            auto str = fancy_to_string(true);
            CHECK(str == "true");
        }

        SECTION("false")
        {
            auto str = fancy_to_string(false);
            CHECK(str == "false");
        }

        SECTION("integer")
        {
            auto str = fancy_to_string(10);
            CHECK(str == "10");
        }

        SECTION("floating point")
        {
            auto str = fancy_to_string(7.5);
            CHECK(str == "7.5");
        }
    }

    SECTION("strings")
    {
        SECTION("long strings usually print")
        {
            auto str = fancy_to_string(
                           "The quick brown fox jumps over the lazy brown dog");
            CHECK(str ==
                  "\"The quick brown fox jumps over the lazy brown dog\"");
        }

        SECTION("long strings can be shortened")
        {
            fancy_serializer_style style;
            style.strings_maximum_length = 10;

            auto str = fancy_to_string(
                           "The quick brown fox jumps over the lazy brown dog",
                           style);
            CHECK(str == "\"The qu...g\"");
        }

        SECTION("requesting extremely short strings limits what is included")
        {
            const char* const quick = "The quick brown fox jumps over the lazy brown dog";

            std::pair<unsigned, const char*> tests[] =
            {
                {5, "\"T...g\""},
                {4, "\"T...\""},
                {3, "\"...\""},
                {2, "\"..\""},
                {1, "\".\""},
            };

            for (auto test : tests)
            {
                fancy_serializer_style style;
                style.strings_maximum_length = test.first;
                auto str = fancy_to_string(quick, style);
                CHECK(str == test.second);
            }
        }

        SECTION("But you cannot ask for a length of zero; that means unlimited")
        {
            fancy_serializer_style style;
            style.strings_maximum_length = 0;

            auto str = fancy_to_string(
                           "The quick brown fox jumps over the lazy brown dog",
                           style);
            CHECK(str ==
                  "\"The quick brown fox jumps over the lazy brown dog\"");
        }

        SECTION("\"Limiting\" to something long doesn't do anything")
        {
            fancy_serializer_style style;
            style.strings_maximum_length = 100;

            auto str = fancy_to_string(
                           "The quick brown fox jumps over the lazy brown dog",
                           style);
            CHECK(str ==
                  "\"The quick brown fox jumps over the lazy brown dog\"");
        }

        // TODO: Handle escape sequences. Figure out what we want the
        // behavior to be, first. :-)
    }

    SECTION("given width")
    {
        fancy_serializer_style style;
        style.indent_step = 4;
        auto str = fancy_to_string({"foo", 1, 2, 3, false, {{"one", 1}}}, style);
        CHECK(str ==
              "[\n"
              "    \"foo\",\n"
              "    1,\n"
              "    2,\n"
              "    3,\n"
              "    false,\n"
              "    {\n"
              "        \"one\": 1\n"
              "    }\n"
              "]"
             );
    }

    SECTION("given fill")
    {
        fancy_serializer_style style;
        style.indent_step = 1;
        style.indent_char = '\t';

        auto str = fancy_to_string({"foo", 1, 2, 3, false, {{"one", 1}}}, style);
        CHECK(str ==
              "[\n"
              "\t\"foo\",\n"
              "\t1,\n"
              "\t2,\n"
              "\t3,\n"
              "\tfalse,\n"
              "\t{\n"
              "\t\t\"one\": 1\n"
              "\t}\n"
              "]"
             );
    }
}