tests/test_json.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2024 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "util_allocator.h"
#include "cx/test.h"

#include "cx/json.h"
#include "cx/compare.h"

CX_TEST(test_json_init_default) {
    CxJson json;
    CX_TEST_DO {
        cxJsonInit(&json, NULL);
        CX_TEST_ASSERT(json.states == json.states_internal);
        CX_TEST_ASSERT(json.states_size == 1);
        CX_TEST_ASSERT(json.states_capacity >= 8);
        CX_TEST_ASSERT(json.vbuf == json.vbuf_internal);
        CX_TEST_ASSERT(json.vbuf_size == 0);
        CX_TEST_ASSERT(json.vbuf_capacity >= 8);
        cxJsonDestroy(&json);
    }
}

CX_TEST(test_json_simple_object) {
    cxstring text = cx_str(
            "{\n"
            "\t\"message\":\"success\",\n"
            "\t\"position\":{\n"
            "\t\t\"longitude\":-94.7099,\n"
            "\t\t\"latitude\":51.5539\n"
            "\t},\n"
            "\t\"timestamp\":1729348561,\n"
            "\t\"alive\":true\n"
            "}"
    );

    CX_TEST_DO {
        CxJsonStatus result;

        CxJson json;
        cxJsonInit(&json, NULL);
        cxJsonFill(&json, text);

        // parse the big fat object
        CxJsonValue *obj;
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);

        // check the contents
        CX_TEST_ASSERT(cxJsonIsObject(obj));

        CxJsonValue *message = cxJsonObjGet(obj, "message");
        CX_TEST_ASSERT(cxJsonIsString(message));
        CX_TEST_ASSERT(0 == cx_strcmp(
                cxJsonAsCxString(message),
                cx_str("success"))
        );

        CxJsonValue *position = cxJsonObjGet(obj, "position");
        CX_TEST_ASSERT(cxJsonIsObject(position));
        CxJsonValue *longitude = cxJsonObjGet(position, "longitude");
        CX_TEST_ASSERT(cxJsonIsNumber(longitude));
        CX_TEST_ASSERT(!cxJsonIsInteger(longitude));
        CX_TEST_ASSERT(0 == cx_vcmp_double(cxJsonAsDouble(longitude), -94.7099));
        CX_TEST_ASSERT(cxJsonAsInteger(longitude) == -94);
        CxJsonValue *latitude = cxJsonObjGet(position, "latitude");
        CX_TEST_ASSERT(cxJsonIsNumber(latitude));
        CX_TEST_ASSERT(!cxJsonIsInteger(latitude));
        CX_TEST_ASSERT(0 == cx_vcmp_double(cxJsonAsDouble(latitude), 51.5539));
        CX_TEST_ASSERT(cxJsonAsInteger(latitude) == 51);

        CxJsonValue *timestamp = cxJsonObjGet(obj, "timestamp");
        CX_TEST_ASSERT(cxJsonIsInteger(timestamp));
        CX_TEST_ASSERT(cxJsonIsNumber(timestamp));
        CX_TEST_ASSERT(cxJsonAsInteger(timestamp) == 1729348561);
        CX_TEST_ASSERT(cxJsonAsDouble(timestamp) == 1729348561.0);

        CxJsonValue *alive = cxJsonObjGet(obj, "alive");
        CX_TEST_ASSERT(cxJsonIsBool(alive));
        CX_TEST_ASSERT(cxJsonIsTrue(alive));
        CX_TEST_ASSERT(!cxJsonIsFalse(alive));
        CX_TEST_ASSERT(cxJsonAsBool(alive));

        // this recursively frees everything else
        cxJsonValueFree(obj);

        // we only have one object that already contained all the data
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_DATA);

        cxJsonDestroy(&json);
    }
}

CX_TEST(test_json_escaped_strings) {
    cxstring text = cx_str(
            "{\n"
            "\t\"object\":\"{\\n\\t\\\"object\\\":null\\n}\",\n"
            "\t\"ctrl-chars\":\"\\\\foo\\r\\nbar\\f*ring\\/ring*\\b\"\n"
            "}"
    );

    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        cxJsonFill(&json, text);
        CxJsonValue *obj;
        CxJsonStatus result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsObject(obj));
        CxJsonValue *object = cxJsonObjGet(obj, "object");
        CX_TEST_ASSERT(cxJsonIsString(object));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(object),
            CX_STR("{\n\t\"object\":null\n}"))
        );
        CxJsonValue *ctrl = cxJsonObjGet(obj, "ctrl-chars");
        CX_TEST_ASSERT(cxJsonIsString(ctrl));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(ctrl),
            CX_STR("\\foo\r\nbar\f*ring/ring*\b"))
        );
        cxJsonValueFree(obj);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_escaped_unicode_strings) {
    cxstring text = cx_str(
            "{\n"
            "\"ascii\":\"\\u0041\\u0053\\u0043\\u0049\\u0049\",\n"
            "\"unicode\":\"\\u00df\\u00DF\",\n"
            "\"mixed\":\"mixed ä ö \\u00e4 \\u00f6\",\n"
            "\"wide\":\"\\u03a3\\u29b0\",\n"
            "\"surrogatepair1\":\"\\ud83e\\udff5\",\n"
            "\"surrogatepair2\":\"test\\ud83e\\udff1AA\"\n,"
            "\"mixed2\":\"123\\u03a3\\ud83e\\udfc5\\u00df\""
            "}"
    );

    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        cxJsonFill(&json, text);
        CxJsonValue *obj;
        CxJsonStatus result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsObject(obj));
        
        CxJsonValue *ascii = cxJsonObjGet(obj, "ascii");
        CX_TEST_ASSERT(cxJsonIsString(ascii));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(ascii),
            CX_STR("ASCII"))
        );
        
        CxJsonValue *unicode = cxJsonObjGet(obj, "unicode");
        CX_TEST_ASSERT(cxJsonIsString(unicode));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(unicode),
            CX_STR("ßß"))
        );
        
        CxJsonValue *mixed = cxJsonObjGet(obj, "mixed");
        CX_TEST_ASSERT(cxJsonIsString(mixed));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(mixed),
            CX_STR("mixed ä ö ä ö"))
        );
        
        CxJsonValue *wide = cxJsonObjGet(obj, "wide");
        CX_TEST_ASSERT(cxJsonIsString(wide));
        CX_TEST_ASSERT(0 == cx_strcmp(cxJsonAsCxString(wide), CX_STR("Σ⦰")));
        
        CxJsonValue *surrogatepair1 = cxJsonObjGet(obj, "surrogatepair1");
        CX_TEST_ASSERT(cxJsonIsString(surrogatepair1));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(surrogatepair1),
            CX_STR("\xf0\x9f\xaf\xb5"))
        );
        
        CxJsonValue *surrogatepair2 = cxJsonObjGet(obj, "surrogatepair2");
        CX_TEST_ASSERT(cxJsonIsString(surrogatepair2));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(surrogatepair2),
            CX_STR("test\xf0\x9f\xaf\xb1" "AA"))
        );
        
        CxJsonValue *mixed2 = cxJsonObjGet(obj, "mixed2");
        char test[16];
        strncpy(test, mixed2->value.string.ptr, 15);
       CX_TEST_ASSERT(cxJsonIsString(mixed2));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(mixed2),
            CX_STR("123\xce\xa3\xf0\x9f\xaf\x85ß"))
        );
        
        cxJsonValueFree(obj);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_escaped_unicode_malformed) {
    CxJson json;
    cxJsonInit(&json, NULL);
    CxJsonValue *obj;
    CxJsonStatus result;
    CX_TEST_DO {
        cxJsonFill(&json, "\"too few \\u123 digits\"");
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(obj));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(obj),
            CX_STR("too few \\u123 digits")
        ));
        cxJsonValueFree(obj);
        cxJsonFill(&json, "\"too many \\u00E456 digits\"");
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(obj));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(obj),
            CX_STR("too many ä56 digits")
        ));
        cxJsonValueFree(obj);
        cxJsonFill(&json, "\"only high \\uD800 surrogate\"");
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(obj));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(obj),
            CX_STR("only high \\uD800 surrogate")
        ));
        cxJsonValueFree(obj);
        cxJsonFill(&json, "\"only low \\uDC00 surrogate\"");
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(obj));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(obj),
            CX_STR("only low \\uDC00 surrogate")
        ));
        cxJsonValueFree(obj);
        cxJsonFill(&json, "\"two high \\uD800\\uD800 surrogates\"");
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(obj));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(obj),
            CX_STR("two high \\uD800\\uD800 surrogates")
        ));
        cxJsonValueFree(obj);
        cxJsonFill(&json, "\"high plus bullshit \\uD800\\u567 foo\"");
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(obj));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(obj),
            CX_STR("high plus bullshit \\uD800\\u567 foo")
        ));
        cxJsonValueFree(obj);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_escaped_end_of_string) {
    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        // first test, normal scenario
        cxJsonFill(&json, "\"a \\\"test\\\" string\"");
        CxJsonValue *val;
        CxJsonStatus result = cxJsonNext(&json, &val);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(val));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(val),
            cx_str("a \"test\" string"))
        );
        cxJsonValueFree(val);

        // second test - uncompleted token with hanging escape char
        cxJsonFill(&json, "\"a \\\"test\\");
        result = cxJsonNext(&json, &val);
        CX_TEST_ASSERT(result == CX_JSON_INCOMPLETE_DATA);
        cxJsonFill(&json, "\" string\"");
        result = cxJsonNext(&json, &val);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(val));
        CX_TEST_ASSERT(0 == cx_strcmp(
            cxJsonAsCxString(val),
            cx_str("a \"test\" string"))
        );
        cxJsonValueFree(val);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_object_incomplete_token) {
    cxstring text = cx_str(
            "{\"message\":\"success\"  ,     \"__timestamp\":1729348561}");
    cxstring parts[16];
    size_t nparts = 0; // split the json text into mulple parts
    for(size_t i=0;i<text.length;i+=4) {
        parts[nparts++] = cx_strsubsl(text, i, 4);
    }
    
    CX_TEST_DO {
        CxJsonStatus result;

        CxJson json;
        cxJsonInit(&json, NULL);
        CxJsonValue *obj;
        
        size_t part = 0;
        while(part < nparts - 1) {
            cxJsonFill(&json, parts[part]);
            part++;
            result = cxJsonNext(&json, &obj);
            CX_TEST_ASSERT(result == CX_JSON_INCOMPLETE_DATA);
        }
        cxJsonFill(&json, parts[nparts - 1]);
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsObject(obj));
        
        CxJsonValue *message = cxJsonObjGet(obj, "message");
        CX_TEST_ASSERT(cxJsonIsString(message));
        CX_TEST_ASSERT(0 == cx_strcmp(
                cxJsonAsCxString(message),
                cx_str("success"))
        );
        CxJsonValue *timestamp = cxJsonObjGet(obj, "__timestamp");
        CX_TEST_ASSERT(message->type == CX_JSON_STRING);
        CX_TEST_ASSERT(cxJsonIsInteger(timestamp));
        CX_TEST_ASSERT(cxJsonAsInteger(timestamp) == 1729348561);
        
        // this recursively frees everything else
        cxJsonValueFree(obj);

        // now there is everything read
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_DATA);

        cxJsonDestroy(&json);
    }
}

CX_TEST(test_json_token_wrongly_completed) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    const CxAllocator *alloc = &talloc.base;

    cxstring text = cx_str("{\"number\": 47110815!}");
    cxstring part1 = cx_strsubsl(text, 0, 16);
    cxstring part2 = cx_strsubs(text, 16);

    CX_TEST_DO {
        CxJson json;
        cxJsonInit(&json, alloc);

        CxJsonStatus result;
        CxJsonValue *obj;

        cxJsonFill(&json, part1);
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_INCOMPLETE_DATA);
        cxJsonFill(&json, part2);
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_FORMAT_ERROR_NUMBER);
        CX_TEST_ASSERT(obj->type == CX_JSON_NOTHING);

        cxJsonDestroy(&json);
        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_subsequent_fill) {
    cxstring text = cx_str(
            "{\"message\":\"success\"  ,     \"__timestamp\":1729348561}");

    cxstring part1 = cx_strsubsl(text, 0, 25);
    cxstring part2 = cx_strsubs(text, 25);

    CX_TEST_DO {
        CxJson json;
        cxJsonInit(&json, NULL);
        CxJsonValue *obj;

        cxJsonFill(&json, part1);
        cxJsonFill(&json, part2);
        CxJsonStatus result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsObject(obj));

        CxJsonValue *message = cxJsonObjGet(obj, "message");
        CX_TEST_ASSERT(cxJsonIsString(message));
        CX_TEST_ASSERT(0 == cx_strcmp(
                cxJsonAsCxString(message),
                cx_str("success"))
        );
        CxJsonValue *timestamp = cxJsonObjGet(obj, "__timestamp");
        CX_TEST_ASSERT(message->type == CX_JSON_STRING);
        CX_TEST_ASSERT(cxJsonIsInteger(timestamp));
        CX_TEST_ASSERT(cxJsonAsInteger(timestamp) == 1729348561);

        cxJsonValueFree(obj);
        result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_DATA);

        cxJsonDestroy(&json);
    }
}

CX_TEST(test_json_object_error) {
    cxstring text0 = cx_str(
            "{\n"
            "\t\"message\":\"success\",\n"
            "\t\"data\":{\n"
            "\t\t\"obj\":{\n"
            "\t\t\t\"array\": [1, 2, 3, ?syntaxerror? ]\n"
            "\t\t\"}\n"
            "\t},\n"
            "\t\"timestamp\":1729348561,\n"
            "}"
    );
    cxstring text1 = cx_str("{ \"string\" }");
    cxstring text2 = cx_str("{ \"a\" : }");
    cxstring text3 = cx_str("{ \"a\" : \"b\" ]");
    cxstring text4 = cx_str("{ \"name\": \"value\" ]");
    
    cxstring tests[] = { text0, text1, text2, text3, text4 };
    CxJsonStatus errors[] = {
        CX_JSON_FORMAT_ERROR_NUMBER,
        CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN,
        CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN,
        CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN,
        CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN
    };
    
    CX_TEST_DO {
        CxJsonStatus result;
        CxJson json;
        CxJsonValue *obj = NULL;
        
        for(int i=0;i<5;i++) {
            cxJsonInit(&json, NULL);
            cxJsonFill(&json, tests[i]);
            result = cxJsonNext(&json, &obj);

            CX_TEST_ASSERT(result == errors[i]);
            CX_TEST_ASSERT(obj != NULL && obj->type == CX_JSON_NOTHING);
            cxJsonDestroy(&json);
        }
    }
}

CX_TEST(test_json_large_nesting_depth) {
    CxJson json;
    CxJsonValue *d1;
    cxstring text = cx_str("{\"test\": [{},{\"foo\": [[{\"bar\":[4, 2, [null, {\"key\": 47}]]}]]}]}");
    CX_TEST_DO {
        cxJsonInit(&json, NULL);
        cxJsonFill(&json, text);
        cxJsonNext(&json, &d1);

        CX_TEST_ASSERT(d1 != NULL);
        CX_TEST_ASSERT(cxJsonIsObject(d1));
        CxJsonValue *d2 = cxJsonObjGet(d1, "test");
        CX_TEST_ASSERT(cxJsonIsArray(d2));
        CX_TEST_ASSERT(cxJsonArrSize(d2) == 2);
        CxJsonValue *d3 = cxJsonArrGet(d2, 1);
        CX_TEST_ASSERT(cxJsonIsObject(d3));
        CxJsonValue *d4 = cxJsonObjGet(d3, "foo");
        CX_TEST_ASSERT(cxJsonIsArray(d4));
        CX_TEST_ASSERT(cxJsonArrSize(d4) == 1);
        CxJsonValue *d5 = cxJsonArrGet(d4, 0);
        CX_TEST_ASSERT(cxJsonIsArray(d5));
        CX_TEST_ASSERT(cxJsonArrSize(d5) == 1);
        CxJsonValue *d6 = cxJsonArrGet(d5, 0);
        CX_TEST_ASSERT(cxJsonIsObject(d6));
        CxJsonValue *d7 = cxJsonObjGet(d6, "bar");
        CX_TEST_ASSERT(cxJsonIsArray(d7));
        CX_TEST_ASSERT(cxJsonArrSize(d7) == 3);
        CxJsonValue *d8 = cxJsonArrGet(d7, 2);
        CX_TEST_ASSERT(cxJsonIsArray(d8));
        CX_TEST_ASSERT(cxJsonArrSize(d8) == 2);
        CxJsonValue *d9a = cxJsonArrGet(d8, 0);
        CX_TEST_ASSERT(cxJsonIsNull(d9a));
        CxJsonValue *d9b = cxJsonArrGet(d8, 1);
        CX_TEST_ASSERT(cxJsonIsObject(d9b));
        CxJsonValue *d10 = cxJsonObjGet(d9b, "key");
        CX_TEST_ASSERT(cxJsonIsInteger(d10));
        CX_TEST_ASSERT(cxJsonAsInteger(d10) == 47);

        CX_TEST_ASSERT(json.states != json.states_internal);
        CX_TEST_ASSERT(json.states_capacity > cx_nmemb(json.states_internal));
        
        cxJsonValueFree(d1);
        cxJsonDestroy(&json);
    }
}

CX_TEST(test_json_number) {
    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        CxJsonValue *v;
        CxJsonStatus result;

        cxJsonFill(&json, "3.1415 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsNumber(v));
        CX_TEST_ASSERT(0 == cx_vcmp_double(cxJsonAsDouble(v), 3.1415));
        cxJsonValueFree(v);

        cxJsonFill(&json, "-47.11e2 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsNumber(v));
        CX_TEST_ASSERT(0 == cx_vcmp_double(cxJsonAsDouble(v), -4711.0));
        cxJsonValueFree(v);

        cxJsonFill(&json, "0.815e-3 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsNumber(v));
        CX_TEST_ASSERT(0 == cx_vcmp_double(cxJsonAsDouble(v), 0.000815));
        cxJsonValueFree(v);

        cxJsonFill(&json, "1.23E4 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsNumber(v));
        CX_TEST_ASSERT(cxJsonAsInteger(v) == 12300);
        CX_TEST_ASSERT(cxJsonAsDouble(v) == 12300.0);
        cxJsonValueFree(v);

        cxJsonFill(&json, "18446744073709551615.0123456789 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsNumber(v));
        // be as precise as possible
        // TODO: this might produce format error / out of range in future implementations
        CX_TEST_ASSERT(0 == cx_vcmp_double(cxJsonAsDouble(v), 1.8446744073709552e+19));
        cxJsonValueFree(v);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_number_format_errors) {
    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        CxJsonValue *v;
        CxJsonStatus result;

        cxJsonFill(&json, "+3.1415 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
                        "leading plus is not RFC-8259 compliant");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "0.815e-3.0 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
                        "exponent must be an integer");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "3.14e ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
                        "exponent cannot be empty");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "3.14e~7 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
                       "exponent cannot start with bullshit");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "1.23e4f ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
            "non-digits in exponent");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "1.23f ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
            "non-digits in value");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "1.23.45 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
            "multiple decimal separators");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);

        cxJsonFill(&json, "184467440737095516150123456789 ");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERTM(result == CX_JSON_FORMAT_ERROR_NUMBER,
            "30 digit int does not fit into 64-bit int");
        CX_TEST_ASSERT(v->type == CX_JSON_NOTHING);
        cxJsonReset(&json);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_multiple_values) {
    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        CxJsonValue *v;
        CxJsonStatus result;
        
        // read number
        cxJsonFill(&json, "10\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsNumber(v));
        CX_TEST_ASSERT(cxJsonAsInteger(v) == 10);
        cxJsonValueFree(v);
        // read remaining '\n'
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_INCOMPLETE_DATA);
        // read string
        cxJsonFill(&json, "\"hello world\"\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsString(v));
        CX_TEST_ASSERT(!cx_strcmp(cxJsonAsCxString(v), CX_STR("hello world")));
        cxJsonValueFree(v);
        // don't process the remaining newline this time
        // read obj
        cxJsonFill(&json, "{ \"value\": \"test\" }\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsObject(v));
        CxJsonValue *value = cxJsonObjGet(v, "value");
        CX_TEST_ASSERT(cxJsonAsString(value));
        cxJsonValueFree(v);
        // read array
        cxJsonFill(&json, "[ 0, 1, 2, 3, 4, 5 ]\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsArray(v));
        CxJsonValue *a0 = cxJsonArrGet(v, 0);
        CxJsonValue *a3 = cxJsonArrGet(v, 3);
        CX_TEST_ASSERT(cxJsonIsNumber(a0));
        CX_TEST_ASSERT(cxJsonAsInteger(a0) == 0);
        CX_TEST_ASSERT(cxJsonIsNumber(a3));
        CX_TEST_ASSERT(cxJsonAsInteger(a3) == 3);
        cxJsonValueFree(v);
        // read literal
        cxJsonFill(&json, "true\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsLiteral(v));
        CX_TEST_ASSERT(cxJsonIsBool(v));
        CX_TEST_ASSERT(cxJsonIsTrue(v));
        CX_TEST_ASSERT(cxJsonAsBool(v));
        cxJsonValueFree(v);
        cxJsonFill(&json, "false\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsLiteral(v));
        CX_TEST_ASSERT(cxJsonIsBool(v));
        CX_TEST_ASSERT(cxJsonIsFalse(v));
        CX_TEST_ASSERT(!cxJsonAsBool(v));
        cxJsonValueFree(v);
        cxJsonFill(&json, "null\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsLiteral(v));
        CX_TEST_ASSERT(!cxJsonIsBool(v));
        CX_TEST_ASSERT(cxJsonIsNull(v));
        cxJsonValueFree(v);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_array_iterator) {
    CxJson json;
    cxJsonInit(&json, NULL);
    CX_TEST_DO {
        CxJsonValue *v;
        CxJsonStatus result;
        cxJsonFill(&json, "[ 0, 3, 6, 9, 12, 15 ]\n");
        result = cxJsonNext(&json, &v);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(cxJsonIsArray(v));
        CxIterator iter = cxJsonArrIter(v);
        unsigned i = 0;
        cx_foreach(CxJsonValue*, elem, iter) {
            CX_TEST_ASSERT(cxJsonIsNumber(elem));
            CX_TEST_ASSERT(i == cxJsonAsInteger(elem));
            i += 3;
        }
        cxJsonValueFree(v);
    }
    cxJsonDestroy(&json);
}

CX_TEST(test_json_allocator) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;

    cxstring text = cx_str(
            "{\n"
            "\t\"message\":\"success\",\n"
            "\t\"data\":[\"value1\",{\"x\":123, \"y\":523 }]\n"
            "}"
    );

    CX_TEST_DO {
        CxJson json;
        cxJsonInit(&json, allocator);
        cxJsonFill(&json, text);
        
        CxJsonValue *obj;
        CxJsonStatus result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_NO_ERROR);
        CX_TEST_ASSERT(obj->allocator == allocator);
        
        // this recursively frees everything 
        cxJsonValueFree(obj);
        cxJsonDestroy(&json);

        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_allocator_parse_error) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;

    cxstring text = cx_str(
            "{\n"
            "\t\"message\":\"success\"\n" // <-- missing comma
            "\t\"data\":[\"value1\",{\"x\":123, \"y\":523 }]\n"
            "}"
    );

    CX_TEST_DO {
        CxJson json;
        cxJsonInit(&json, allocator);
        cxJsonFill(&json, text);

        CxJsonValue *obj = NULL;
        CxJsonStatus result = cxJsonNext(&json, &obj);
        CX_TEST_ASSERT(result == CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN);
        CX_TEST_ASSERT(obj != NULL && obj->type == CX_JSON_NOTHING);

        // clean-up any left-over memory
        cxJsonDestroy(&json);

        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_create_value) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;
    CX_TEST_DO {
        /*
         * This is the value we want to create in this test:
         *
         * {
         *    "bool": false,
         *    "int": 47,
         *    "strings": [ "hello", "world" ],
         *    "nested": {
         *       "string": "test",
         *       "floats": [ 3.1415, 47.11, 8.15 ],
         *       "ints": [ 4, 8, 15, 16, 23, 42 ],
         *       "literals": [ true, null, false ]
         *    }
         * }
         */


        // create the object
        CxJsonValue *obj = cxJsonCreateObj(allocator);
        CX_TEST_ASSERT(obj != NULL);
        CX_TEST_ASSERT(cxJsonIsObject(obj));
        CX_TEST_ASSERT(obj->allocator == allocator);

        // add the members
        {
            cxJsonObjPutLiteral(obj, CX_STR("bool"), CX_JSON_FALSE);
            cxJsonObjPutInteger(obj, CX_STR("int"), 47);
            CxJsonValue *strings = cxJsonObjPutArr(obj, CX_STR("strings"));
            CX_TEST_ASSERT(strings != NULL);
            CX_TEST_ASSERT(cxJsonIsArray(strings));
            const char* str[] = {"hello", "world"};
            CX_TEST_ASSERT(0 == cxJsonArrAddStrings(strings, str, 2));

            CxJsonValue *nested = cxJsonObjPutObj(obj, CX_STR("nested"));
            CX_TEST_ASSERT(nested != NULL);
            CX_TEST_ASSERT(cxJsonIsObject(nested));
            cxJsonObjPutCxString(nested, CX_STR("string"), CX_STR("test"));

            cxJsonArrAddNumbers(cxJsonObjPutArr(nested, CX_STR("floats")),
                (double[]){3.1415, 47.11, 8.15}, 3);
            cxJsonArrAddIntegers(cxJsonObjPutArr(nested, CX_STR("ints")),
                (int64_t[]){4, 8, 15, 16, 23, 42}, 6);
            cxJsonArrAddLiterals(cxJsonObjPutArr(nested, CX_STR("literals")),
                (CxJsonLiteral[]){CX_JSON_TRUE, CX_JSON_NULL, CX_JSON_FALSE}, 3);
        }

        // verify the contents
        {
            CX_TEST_ASSERT(cxJsonIsFalse(cxJsonObjGet(obj, "bool")));
            CX_TEST_ASSERT(47 == cxJsonAsInteger(cxJsonObjGet(obj, "int")));
            CxJsonValue *strings = cxJsonObjGet(obj, "strings");
            CX_TEST_ASSERT(cxJsonIsArray(strings));
            CX_TEST_ASSERT(2 == cxJsonArrSize(strings));
            CX_TEST_ASSERT(0 == cx_strcmp(CX_STR("hello"), cxJsonAsCxString(cxJsonArrGet(strings, 0))));
            CX_TEST_ASSERT(0 == cx_strcmp(CX_STR("world"), cxJsonAsCxString(cxJsonArrGet(strings, 1))));

            CxJsonValue *nested = cxJsonObjGet(obj, "nested");
            CX_TEST_ASSERT(cxJsonIsObject(nested));
            CX_TEST_ASSERT(0 == strcmp("test", cxJsonAsString(cxJsonObjGet(nested, "string"))));
            CxJsonValue *floats = cxJsonObjGet(nested, "floats");
            CX_TEST_ASSERT(cxJsonIsArray(floats));
            CX_TEST_ASSERT(3 == cxJsonArrSize(floats));
            CX_TEST_ASSERT(3.1415 == cxJsonAsDouble(cxJsonArrGet(floats, 0)));
            CX_TEST_ASSERT(47.11 == cxJsonAsDouble(cxJsonArrGet(floats, 1)));
            CX_TEST_ASSERT(8.15 == cxJsonAsDouble(cxJsonArrGet(floats, 2)));
            CxJsonValue *ints = cxJsonObjGet(nested, "ints");
            CX_TEST_ASSERT(cxJsonIsArray(ints));
            CX_TEST_ASSERT(6 == cxJsonArrSize(ints));
            CX_TEST_ASSERT(4 == cxJsonAsInteger(cxJsonArrGet(ints, 0)));
            CX_TEST_ASSERT(8 == cxJsonAsInteger(cxJsonArrGet(ints, 1)));
            CX_TEST_ASSERT(15 == cxJsonAsInteger(cxJsonArrGet(ints, 2)));
            CX_TEST_ASSERT(16 == cxJsonAsInteger(cxJsonArrGet(ints, 3)));
            CX_TEST_ASSERT(23 == cxJsonAsInteger(cxJsonArrGet(ints, 4)));
            CX_TEST_ASSERT(42 == cxJsonAsInteger(cxJsonArrGet(ints, 5)));
            CxJsonValue *literals = cxJsonObjGet(nested, "literals");
            CX_TEST_ASSERT(cxJsonIsArray(literals));
            CX_TEST_ASSERT(3 == cxJsonArrSize(literals));
            CX_TEST_ASSERT(cxJsonIsTrue(cxJsonArrGet(literals, 0)));
            CX_TEST_ASSERT(cxJsonIsNull(cxJsonArrGet(literals, 1)));
            CX_TEST_ASSERT(cxJsonIsFalse(cxJsonArrGet(literals, 2)));
        }

        // destroy the value and verify the allocations
        cxJsonValueFree(obj);
        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}


CX_TEST_SUBROUTINE(test_json_write_sub,
        const CxAllocator *allocator,
        cxstring expected,
        const CxJsonWriter *writer
) {
    // create the value
    CxJsonValue *obj = cxJsonCreateObj(allocator);
    cxJsonObjPutLiteral(obj, CX_STR("bool"), CX_JSON_FALSE);
    cxJsonObjPutNumber(obj, CX_STR("int"), 47); // purposely use PutNumber to put an int
    CxJsonValue *strings = cxJsonObjPutArr(obj, CX_STR("strings"));
    cxJsonArrAddCxStrings(strings, (cxstring[]) {CX_STR("hello"), CX_STR("world")}, 2);
    CxJsonValue *nested = cxJsonObjPutObj(obj, CX_STR("nested"));
    CxJsonValue *objects = cxJsonObjPutArr(nested, CX_STR("objects"));
    CxJsonValue *obj_in_arr[2] = {cxJsonCreateObj(allocator), cxJsonCreateObj(allocator)};
    cxJsonObjPutInteger(obj_in_arr[0], CX_STR("name1"), 1);
    cxJsonObjPutInteger(obj_in_arr[0], CX_STR("name2"), 3);
    cxJsonObjPutInteger(obj_in_arr[1], CX_STR("name2"), 7);
    cxJsonObjPutInteger(obj_in_arr[1], CX_STR("name1"), 3);
    cxJsonArrAddValues(objects, obj_in_arr, 2);
    cxJsonArrAddNumbers(cxJsonObjPutArr(nested, CX_STR("floats")),
                        (double[]){3.1415, 47.11, 8.15}, 3);
    cxJsonArrAddLiterals(cxJsonObjPutArr(nested, CX_STR("literals")),
                         (CxJsonLiteral[]){CX_JSON_TRUE, CX_JSON_NULL, CX_JSON_FALSE}, 3);
    CxJsonValue *ints = cxJsonObjPutArr(nested, CX_STR("ints"));
    cxJsonArrAddIntegers(ints, (int64_t[]){4, 8, 15}, 3);
    CxJsonValue *nested_array = cxJsonCreateArr(allocator);
    cxJsonArrAddValues(ints, &nested_array, 1);
    cxJsonArrAddIntegers(nested_array, (int64_t[]){16, 23}, 2);
    cxJsonArrAddIntegers(ints, (int64_t[]){42}, 1);

    // write it to a buffer
    CxBuffer buf;
    cxBufferInit(&buf, NULL, 512, NULL, CX_BUFFER_DEFAULT);
    int result = cxJsonWrite(&buf, obj, cxBufferWriteFunc, writer);
    cxBufferTerminate(&buf); // makes debugging easier
    CX_TEST_ASSERT(result == 0);

    // compare the string
    CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), expected));

    // destroy everything
    cxBufferDestroy(&buf);
    cxJsonValueFree(obj);
}

CX_TEST(test_json_write_default_format) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;
    CX_TEST_DO {
        // expected value
        cxstring expected = CX_STR(
"{\"bool\":false,"
"\"int\":47,"
"\"nested\":{"
"\"floats\":[3.1415,47.11,8.15],"
"\"ints\":[4,8,15,[16,23],42],"
"\"literals\":[true,null,false],"
"\"objects\":[{"
"\"name1\":1,"
"\"name2\":3"
"},{"
"\"name1\":3,"
"\"name2\":7"
"}]"
"},"
"\"strings\":[\"hello\",\"world\"]"
"}"
        );

        CxJsonWriter writer = cxJsonWriterCompact();
        CX_TEST_CALL_SUBROUTINE(test_json_write_sub, allocator, expected, &writer);
        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_write_pretty_default_spaces) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;
    CX_TEST_DO {
        cxstring expected = CX_STR(
"{\n"
"    \"bool\": false,\n"
"    \"int\": 47,\n"
"    \"nested\": {\n"
"        \"floats\": [3.1415, 47.11, 8.15],\n"
"        \"ints\": [4, 8, 15, [16, 23], 42],\n"
"        \"literals\": [true, null, false],\n"
"        \"objects\": [{\n"
"            \"name1\": 1,\n"
"            \"name2\": 3\n"
"        }, {\n"
"            \"name1\": 3,\n"
"            \"name2\": 7\n"
"        }]\n"
"    },\n"
"    \"strings\": [\"hello\", \"world\"]\n"
"}"
        );

        CxJsonWriter writer = cxJsonWriterPretty(true);
        CX_TEST_CALL_SUBROUTINE(test_json_write_sub, allocator, expected, &writer);
        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_write_pretty_default_tabs) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;
    CX_TEST_DO {
        cxstring expected = CX_STR(
"{\n"
"\t\"bool\": false,\n"
"\t\"int\": 47,\n"
"\t\"nested\": {\n"
"\t\t\"floats\": [3.1415, 47.11, 8.15],\n"
"\t\t\"ints\": [4, 8, 15, [16, 23], 42],\n"
"\t\t\"literals\": [true, null, false],\n"
"\t\t\"objects\": [{\n"
"\t\t\t\"name1\": 1,\n"
"\t\t\t\"name2\": 3\n"
"\t\t}, {\n"
"\t\t\t\"name1\": 3,\n"
"\t\t\t\"name2\": 7\n"
"\t\t}]\n"
"\t},\n"
"\t\"strings\": [\"hello\", \"world\"]\n"
"}"
        );
        CxJsonWriter writer = cxJsonWriterPretty(false);
        CX_TEST_CALL_SUBROUTINE(test_json_write_sub, allocator, expected, &writer);
        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_write_pretty_preserve_order) {
    CxTestingAllocator talloc;
    cx_testing_allocator_init(&talloc);
    CxAllocator *allocator = &talloc.base;
    CX_TEST_DO {
        cxstring expected = CX_STR(
"{\n"
"    \"bool\": false,\n"
"    \"int\": 47,\n"
"    \"strings\": [\"hello\", \"world\"],\n"
"    \"nested\": {\n"
"        \"objects\": [{\n"
"            \"name1\": 1,\n"
"            \"name2\": 3\n"
"        }, {\n"
"            \"name2\": 7,\n"
"            \"name1\": 3\n"
"        }],\n"
"        \"floats\": [3.1415, 47.11, 8.15],\n"
"        \"literals\": [true, null, false],\n"
"        \"ints\": [4, 8, 15, [16, 23], 42]\n"
"    }\n"
"}"
        );

        CxJsonWriter writer = cxJsonWriterPretty(true);
        writer.sort_members = false;
        CX_TEST_CALL_SUBROUTINE(test_json_write_sub, allocator, expected, &writer);
        CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc));
    }
    cx_testing_allocator_destroy(&talloc);
}

CX_TEST(test_json_write_frac_max_digits) {
    CxJsonValue* num = cxJsonCreateNumber(NULL, 3.141592653589793);
    CxJsonWriter writer = cxJsonWriterCompact();
    CxBuffer buf;
    cxBufferInit(&buf, NULL, 32, NULL, 0);
    CX_TEST_DO {
        // test default settings (6 digits)
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("3.141592")));

        // test too many digits
        cxBufferReset(&buf);
        writer.frac_max_digits = 200;
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("3.141592653589793")));
        
        // test 0 digits
        cxBufferReset(&buf);
        writer.frac_max_digits = 0;
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("3")));

        // test 2 digits
        cxBufferReset(&buf);
        writer.frac_max_digits = 2;
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("3.14")));

        // test 3 digits
        cxBufferReset(&buf);
        writer.frac_max_digits = 3;
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("3.141")));

        // test 6 digits, but two are left of the decimal point
        num->value.number = 47.110815;
        cxBufferReset(&buf);
        writer.frac_max_digits = 6;
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("47.110815")));

        // test 4 digits with exponent
        num->value.number = 5.11223344e23;
        cxBufferReset(&buf);
        writer.frac_max_digits = 4;
        cxJsonWrite(&buf, num, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("5.1122e+23")));
    }
    cxBufferDestroy(&buf);
    cxJsonValueFree(num);
}

CX_TEST(test_json_write_string_escape) {
    /**
     * According to RFC-8259 we have to test the following characters:
     *    "    quotation mark
     *    \    reverse solidus
     *    /    solidus     ---> we make this optional, see test_json_write_solidus
     *    b    backspace
     *    f    form feed
     *    n    line feed
     *    r    carriage return
     *    t    tab
     * And all other control characters must be encoded uXXXX - in our example the bell character.
     * Also, all unicode characters are encoded that way - in our example the 'ö'.
     */
    CxJsonValue* str = cxJsonCreateString(NULL,
        "hello\twörld\r\nthis is\\a \"string\"\b in \a string\f");
    CxJsonWriter writer = cxJsonWriterCompact();
    CxBuffer buf;
    cxBufferInit(&buf, NULL, 128, NULL, 0);
    CX_TEST_DO {
        cxJsonWrite(&buf, str, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size),
            CX_STR("\"hello\\twörld\\r\\nthis is\\\\a \\\"string\\\"\\b in \\u0007 string\\f\"")));
    }
    cxBufferDestroy(&buf);
    cxJsonValueFree(str);
}

CX_TEST(test_json_write_name_escape) {
    CxJsonValue* obj = cxJsonCreateObj(NULL);
    cxJsonObjPutLiteral(obj,
        CX_STR("hello\twörld\r\nthis is\\a \"string\"\b in \a string\f"), CX_JSON_TRUE);
    CxJsonWriter writer = cxJsonWriterCompact();
    CxBuffer buf;
    cxBufferInit(&buf, NULL, 128, NULL, 0);
    CX_TEST_DO {
        cxJsonWrite(&buf, obj, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size),
            CX_STR("{\"hello\\twörld\\r\\nthis is\\\\a \\\"string\\\"\\b in \\u0007 string\\f\":true}")));
    }
    cxBufferDestroy(&buf);
    cxJsonValueFree(obj);
}

CX_TEST(test_json_write_solidus) {
    CxJsonValue* str = cxJsonCreateString(NULL,"test/solidus");
    CxJsonWriter writer = cxJsonWriterCompact();
    CxBuffer buf;
    cxBufferInit(&buf, NULL, 16, NULL, 0);
    CX_TEST_DO {
        // default: do not escape
        cxJsonWrite(&buf, str, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("\"test/solidus\"")));

        // enable escaping
        writer.escape_slash = true;
        cxBufferReset(&buf);
        cxJsonWrite(&buf, str, cxBufferWriteFunc, &writer);
        CX_TEST_ASSERT(0 == cx_strcmp(cx_strn(buf.space, buf.size), CX_STR("\"test\\/solidus\"")));
    }
    cxBufferDestroy(&buf);
    cxJsonValueFree(str);
}

CxTestSuite *cx_test_suite_json(void) {
    CxTestSuite *suite = cx_test_suite_new("json");

    cx_test_register(suite, test_json_init_default);
    cx_test_register(suite, test_json_simple_object);
    cx_test_register(suite, test_json_escaped_strings);
    cx_test_register(suite, test_json_escaped_unicode_strings);
    cx_test_register(suite, test_json_escaped_unicode_malformed);
    cx_test_register(suite, test_json_escaped_end_of_string);
    cx_test_register(suite, test_json_object_incomplete_token);
    cx_test_register(suite, test_json_token_wrongly_completed);
    cx_test_register(suite, test_json_object_error);
    cx_test_register(suite, test_json_subsequent_fill);
    cx_test_register(suite, test_json_large_nesting_depth);
    cx_test_register(suite, test_json_number);
    cx_test_register(suite, test_json_number_format_errors);
    cx_test_register(suite, test_json_multiple_values);
    cx_test_register(suite, test_json_array_iterator);
    cx_test_register(suite, test_json_allocator);
    cx_test_register(suite, test_json_allocator_parse_error);
    cx_test_register(suite, test_json_create_value);
    cx_test_register(suite, test_json_write_default_format);
    cx_test_register(suite, test_json_write_pretty_default_spaces);
    cx_test_register(suite, test_json_write_pretty_default_tabs);
    cx_test_register(suite, test_json_write_pretty_preserve_order);
    cx_test_register(suite, test_json_write_frac_max_digits);
    cx_test_register(suite, test_json_write_string_escape);
    cx_test_register(suite, test_json_write_name_escape);
    cx_test_register(suite, test_json_write_solidus);
    
    return suite;
}