Scarfski/json
1
0
Fork 0
mirror of https://github.com/nlohmann/json.git synced 2026-09-30 14:05:18 +00:00
Code Issues Packages Projects Releases Wiki Activity
Files
a210437b301142ff170d27e06089cf09e53f6795
json/tests/src/unit-json_view.cpp
Niels Lohmann a210437b30 Fix CI: json_view value tests without exceptions and with GCC 
- ci_test_noexceptions: exception_of() and without_path() exist only
  with exceptions (they catch outside a CHECK_THROWS, which aborts with
  JSON_NOEXCEPTION); compile the comparisons of the conversion, value(),
  and JSON pointer errors only with exceptions as well.
- ci_test_gcc: -Werror=unused-result for static_cast<void>(j.contains(p))
  (GCC's warn_unused_result ignores a cast to void); store the result.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-29 22:44:33 +02:00

1054 lines
42 KiB
C++
Raw Blame History

// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++ (supporting code)
// | | |__ | | | | | | version 3.12.0
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
#include "doctest_compatibility.h"
#include <nlohmann/json_view.hpp>
using nlohmann::json;
using nlohmann::ordered_json;
using nlohmann::json_document;
using nlohmann::json_view;
using nlohmann::ordered_json_document;
using nlohmann::ordered_json_view;
#include <algorithm>
#include <array>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <iterator>
#include <list>
#include <map>
#include <random>
#include <sstream>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
#ifdef JSON_HAS_CPP_17
#include <string_view>
#endif
namespace
{
#if !defined(JSON_NOEXCEPTION)
// the exception parse() throws for a text, or "" if it accepts it
std::string parse_exception(const std::string& text, bool comments = false, bool trailing_commas = false)
{
try
{
const json j = json::parse(text, nullptr, true, comments, trailing_commas);
static_cast<void>(j);
}
catch (const json::exception& e)
{
return e.what();
}
return "";
}
std::string view_exception(const std::string& text, bool comments = false, bool trailing_commas = false)
{
try
{
const json_document d = json_document::parse(text, true, comments, trailing_commas);
static_cast<void>(d);
}
catch (const json::exception& e)
{
return e.what();
}
return "";
}
#endif
// a small deterministic generator of documents
struct generator
{
std::mt19937 rng{5295}; // NOLINT(cert-msc32-c,cert-msc51-cpp,bugprone-random-generator-seed)
int r(int n)
{
return static_cast<int>(rng() % static_cast<unsigned>(n));
}
void str(std::string& o)
{
static const char* const pieces[] = {"a", "Z", " ", "\\n", "\\\"", "\\u00e9", "\\ud83d\\ude00", "\xc3\xa9", "\xe3\x81\x82", "long text beyond the first sixteen bytes"}; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
o += '"';
for (int n = r(5); n > 0; --n)
{
o += pieces[r(10)];
}
o += '"';
}
void value(std::string& o, int depth)
{
static const char* const scalars[] = {"0", "-1", "123456789012", "18446744073709551615", "18446744073709551616", "-9223372036854775809", // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
"1.5", "-2.25e-3", "1E2", "0.1", "true", "false", "null"
};
const int k = depth > 5 ? 2 + r(4) : r(6);
if (k < 2)
{
const bool object = k == 0;
o += object ? '{' : '[';
for (int i = r(5); i > 0; --i)
{
if (object)
{
str(o);
o += r(2) == 0 ? ":" : " : ";
}
value(o, depth + 1);
o += i > 1 ? ", " : "";
}
o += object ? '}' : ']';
}
else if (k < 4)
{
str(o);
}
else
{
o += scalars[r(13)];
}
}
};
} // namespace
TEST_CASE("json_view")
{
SECTION("types and capacity")
{
for (const char* text :
{"null", "true", "false", "0", "-1", "18446744073709551615", "-9223372036854775808", "18446744073709551616", "1.5",
"\"\"", "\"text\"", "[]", "[1,2,3]", "{}", "{\"a\":1,\"b\":2}" // NOLINT(modernize-raw-string-literal)
})
{
CAPTURE(text);
const json j = json::parse(text);
const json_document d = json_document::parse(text);
const json_view v = d.root();
CHECK(v.type() == j.type());
CHECK(v.is_null() == j.is_null());
CHECK(v.is_boolean() == j.is_boolean());
CHECK(v.is_number() == j.is_number());
CHECK(v.is_number_integer() == j.is_number_integer());
CHECK(v.is_number_unsigned() == j.is_number_unsigned());
CHECK(v.is_number_float() == j.is_number_float());
CHECK(v.is_string() == j.is_string());
CHECK(v.is_array() == j.is_array());
CHECK(v.is_object() == j.is_object());
CHECK(v.is_binary() == j.is_binary());
CHECK(v.is_primitive() == j.is_primitive());
CHECK(v.is_structured() == j.is_structured());
CHECK(!v.is_discarded());
CHECK(static_cast<bool>(v));
CHECK(v.size() == j.size());
CHECK(v.empty() == j.empty());
CHECK(v.materialize() == j);
}
const json_view invalid{};
CHECK(invalid.is_discarded());
CHECK(!static_cast<bool>(invalid));
CHECK(invalid.type() == json::value_t::discarded);
CHECK(invalid.size() == 0);
CHECK(invalid.empty());
CHECK(invalid.materialize().is_discarded());
CHECK(invalid.source_offset() == static_cast<std::size_t>(-1));
}
SECTION("materialize")
{
generator g;
for (int i = 0; i < 2000; ++i)
{
std::string text;
g.value(text, 0);
CAPTURE(text);
CHECK(json_document::parse(text).root().materialize() == json::parse(text));
// member order as ordered_json::parse keeps it
CHECK(ordered_json_document::parse(text).root().materialize().dump() == ordered_json::parse(text).dump());
}
// duplicate keys: the last value, at the position of the first key
CHECK(json_document::parse(R"({"a":1,"b":2,"a":3})").root().materialize() == json::parse(R"({"a":1,"b":2,"a":3})"));
CHECK(ordered_json_document::parse(R"({"a":1,"b":2,"a":3})").root().materialize().dump() == R"({"a":3,"b":2})");
// very deep nesting (iterative, as parse())
const std::string deep = std::string(100000, '[') + std::string(100000, ']');
CHECK(json_document::parse(deep).root().materialize() == json::parse(deep));
#if JSON_DIAGNOSTICS
// the parents are set, so errors name the path
const json m = json_document::parse(R"({"a":{"b":[1]}})").root().materialize();
CHECK_THROWS_WITH_AS(m.at("a").at("b").at(0).at("x"), "[json.exception.type_error.304] (/a/b/0) cannot use at() with number", json::type_error&);
#endif
}
SECTION("parse errors are those of parse()")
{
for (const char* text :
{
"", " ", "[", "]", "{", "[1,]", "{\"a\":1,}", "[1 2]", "{\"a\" 1}", "{1:2}", "tru", "nul", "fals", "truex", "-", "01", "1.", ".5", "1e",
"\"", "\"abc", "\"\\x\"", "\"\\u12\"", "\"\\ud800\"", "\"\\udc00\"", "\"\x01\"", "\"\xff\"", "\"\xc3\"", "[1]x", "/", "/*", "[\n 1,\n x\n]", // NOLINT(modernize-raw-string-literal)
"1e400", "-1e400", "[1.7976931348623159e308]", "{\"a\":\n{\"b\": [1, 2,\n 3 x]}}"
})
{
CAPTURE(text);
#if !defined(JSON_NOEXCEPTION)
const std::string expected = parse_exception(text);
REQUIRE(!expected.empty());
CHECK(view_exception(text) == expected);
#endif
CHECK(!json_document::accept(text));
const json_document d = json_document::parse(text, false);
CHECK(d.is_discarded());
CHECK(d.root().is_discarded());
CHECK(d.node_count() == 0);
}
// the exception types
json_document _;
CHECK_THROWS_AS(_ = json_document::parse("[1,"), json::parse_error&);
CHECK_THROWS_AS(_ = json_document::parse("1e400"), json::out_of_range&);
}
SECTION("parse options")
{
for (const char* text :
{"// c\n[1]", "[1, /* c */ 2]", "[1,]", "{\"a\":1,}", "[1,/* c */]", "/", "/* ", "[1,,]"
})
{
CAPTURE(text);
for (int options = 0; options < 4; ++options)
{
const bool comments = (options & 1) != 0;
const bool trailing_commas = (options & 2) != 0;
CHECK(json_document::accept(text, comments, trailing_commas) == json::accept(text, comments, trailing_commas));
#if !defined(JSON_NOEXCEPTION)
CHECK(view_exception(text, comments, trailing_commas) == parse_exception(text, comments, trailing_commas));
#endif
}
}
}
SECTION("NUL and BOM")
{
const std::string with_nul("[1]\0garbage", 11);
CHECK(json_document::accept(with_nul) == json::accept(with_nul));
const std::string nul_in_comment("[1, // c\0\n2]", 12);
CHECK(json_document::accept(nul_in_comment, true) == json::accept(nul_in_comment, true));
CHECK(json_document::parse("\xEF\xBB\xBF[1]").root().materialize() == json::parse("\xEF\xBB\xBF[1]"));
#if !defined(JSON_NOEXCEPTION)
CHECK(view_exception("\xEF\xBB") == parse_exception("\xEF\xBB"));
#endif
}
SECTION("inputs")
{
const std::string text = R"([1, "two", {"three": 3.5}])";
const json expected = json::parse(text);
// borrowed: the text must outlive the document
const json_document borrowed = json_document::parse(text);
CHECK(!borrowed.owns_source());
CHECK(borrowed.source().data() == text.data());
CHECK(borrowed.root().materialize() == expected);
CHECK(json_document::parse(text.c_str()).root().materialize() == expected);
CHECK(json_document::parse(R"([1, "two", {"three": 3.5}])").root().materialize() == expected);
CHECK(json_document::parse(text.data(), text.data() + text.size()).root().materialize() == expected);
const std::vector<char> chars(text.begin(), text.end());
CHECK(!json_document::parse(chars).owns_source());
CHECK(json_document::parse(chars).root().materialize() == expected);
const std::vector<std::uint8_t> bytes(text.begin(), text.end());
CHECK(json_document::parse(bytes).root().materialize() == expected);
#ifdef JSON_HAS_CPP_17
const std::string_view sv = text;
CHECK(!json_document::parse(sv).owns_source());
CHECK(json_document::parse(sv).root().materialize() == expected);
#endif
// owned
std::string moved = text;
const json_document from_rvalue = json_document::parse(std::move(moved));
CHECK(from_rvalue.owns_source());
CHECK(from_rvalue.root().materialize() == expected);
CHECK(json_document::parse(std::vector<char>(text.begin(), text.end())).owns_source());
CHECK(json_document::parse_copy(text).owns_source());
CHECK(json_document::parse_copy(text).root().materialize() == expected);
std::istringstream stream(text);
const json_document from_stream = json_document::parse(stream);
CHECK(from_stream.owns_source());
CHECK(from_stream.root().materialize() == expected);
const std::list<char> list(text.begin(), text.end());
CHECK(json_document::parse(list.begin(), list.end()).owns_source());
CHECK(json_document::parse(list.begin(), list.end()).root().materialize() == expected);
// iterator pairs: pointers are borrowed, and so are contiguous library
// iterators where the input adapter detects them (C++20)
CHECK(!json_document::parse(text.data(), text.data() + text.size()).owns_source());
const bool contiguous = nlohmann::detail::iterator_input_adapter<std::vector<char>::const_iterator>::supports_bulk_scan;
const json_document from_iterators = json_document::parse(chars.cbegin(), chars.cend());
CHECK(from_iterators.owns_source() != contiguous);
CHECK((from_iterators.source().data() == chars.data()) == contiguous);
CHECK(from_iterators.root().materialize() == expected);
const std::string padded = "x" + text + "x";
CHECK(json_document::parse(padded.begin() + 1, padded.end() - 1).root().materialize() == expected);
CHECK(json_document::parse(chars.cbegin(), chars.cbegin(), false).is_discarded());
const std::wstring wide = L"[\"\u00e4\u20ac\", 1]";
CHECK(json_document::parse(wide).root().materialize() == json::parse(wide));
CHECK(json_document::parse(static_cast<const char*>(nullptr), false).is_discarded());
CHECK(json_document::parse("", false).is_discarded());
}
SECTION("document lifetime and reuse")
{
json_document d;
CHECK(d.is_discarded());
CHECK(d.root().is_discarded());
CHECK(d.node_count() == 0);
CHECK(d.memory_usage() == 0);
CHECK(d.source().empty());
const std::string a = "[1,2,3]";
const std::string b = "{\"x\":[true]}";
d.read(a);
CHECK(d.node_count() == 4);
CHECK(d.root().materialize() == json::parse(a));
d.read(b);
CHECK(d.node_count() == 4);
CHECK(d.root().materialize() == json::parse(b));
d.read("[", false);
CHECK(d.is_discarded());
// views stay valid when the document moves
json_document first = json_document::parse(a);
const json_view root = first.root();
const json_document second = std::move(first);
CHECK(root.materialize() == json::parse(a));
CHECK(second.root().materialize() == json::parse(a));
}
SECTION("memory")
{
std::string big = "[";
for (int i = 0; i < 10000; ++i)
{
big += (i != 0 ? ",\"" : "\"") + std::to_string(i) + "\"";
}
big += ']';
json_document d = json_document::parse(big);
CHECK(d.node_count() == 10001);
const std::size_t before = d.memory_usage();
d.shrink_to_fit(); // (invalidates views, like std::vector::shrink_to_fit)
CHECK(d.memory_usage() <= before);
CHECK(d.node_count() == 10001);
CHECK(d.root().materialize() == json::parse(big));
CHECK(d.root().size() == 10000);
d.shrink_to_fit(); // nothing left to release
// after reading a smaller text, both the index and the decoded strings
// shrink, and the strings are found in their new place
std::string escaped = "[";
for (int i = 0; i < 1000; ++i)
{
escaped += (i != 0 ? ",\"a\\n" : "\"a\\n") + std::to_string(i) + "\"";
}
escaped += ']';
json_document reused = json_document::parse(escaped);
const std::string smaller = "[\"x\\ty\", [true, \"\\u00e4\"]]"; // NOLINT(modernize-raw-string-literal)
reused.read(smaller);
const std::size_t grown = reused.memory_usage();
reused.shrink_to_fit();
CHECK(reused.memory_usage() < grown);
CHECK(reused.root().materialize() == json::parse(smaller));
// an empty document has nothing to release
json_document empty;
empty.shrink_to_fit();
CHECK(empty.memory_usage() == 0);
// a small document stays in the storage block of the header
json_document small = json_document::parse("[1,[2,3],{\"a\":\"b\\n\"}]"); // NOLINT(modernize-raw-string-literal)
small.shrink_to_fit();
CHECK(small.root().materialize() == json::parse("[1,[2,3],{\"a\":\"b\\n\"}]"));
}
SECTION("source offsets")
{
const std::string text = R"( {"key": "value", "escaped": "a\nb", "n": 42})";
const json_document d = json_document::parse(text);
CHECK(d.root().source_offset() == 2);
CHECK(d.root()["key"].source_offset() == text.find("value"));
CHECK(d.root()["escaped"].source_offset() == static_cast<std::size_t>(-1));
CHECK(d.root()["n"].source_offset() == text.find("42"));
}
}
namespace
{
#if !defined(JSON_NOEXCEPTION)
// the exception a call throws, or "" if it throws none
template<typename F>
std::string exception_of(F f)
{
try
{
f();
}
catch (const json::exception& e)
{
return e.what();
}
return "";
}
#endif
// compares a view with the ordered_json value materialize() gives for it:
// types, sizes, elements and members (by index, key, and iteration), in
// document order; duplicate keys are found as their first occurrence
void check_access(const ordered_json_view& v, const ordered_json& j)
{
REQUIRE(v.type() == j.type());
CHECK(std::string(v.type_name()) == j.type_name());
if (v.is_array())
{
REQUIRE(v.size() == j.size());
std::size_t i = 0;
for (const ordered_json_view e : v)
{
CHECK(v[i].materialize() == e.materialize());
CHECK(v.at(i).materialize() == e.materialize());
check_access(e, j[i]);
++i;
}
CHECK(i == v.size());
CHECK(!v[v.size()]);
std::size_t index = 0;
for (const auto& item : v.items())
{
CHECK(item.key() == std::to_string(index));
CHECK(item.value().materialize() == j[index]);
++index;
}
if (!v.empty())
{
CHECK(v.front().materialize() == j.front());
CHECK(v.back().materialize() == j.back());
}
}
else if (v.is_object())
{
std::vector<std::string> keys; // first occurrences, in order
std::size_t members = 0;
for (auto it = v.begin(); it != v.end(); ++it)
{
++members;
const std::string key(it.key().data(), it.key().size());
CHECK(v.contains(key));
CHECK(v.count(key) == 1);
if (std::find(keys.begin(), keys.end(), key) != keys.end())
{
continue; // a duplicate: lookups find the first one
}
keys.push_back(key);
CHECK(v.find(key) == it);
CHECK(v[key].materialize() == it->materialize());
CHECK(v.at(key).materialize() == it.value().materialize());
CHECK(v[key.c_str()].materialize() == (*it).materialize());
}
CHECK(members == v.size());
REQUIRE(keys.size() == j.size());
std::size_t k = 0;
for (const auto& member : j.items())
{
CHECK(keys[k++] == member.key());
}
if (keys.size() == members)
{
// no duplicates: the values are those of the object
for (const auto& key : keys)
{
check_access(v[key], j[key]);
}
if (!v.empty())
{
CHECK(v.front().materialize() == j.front());
CHECK(v.back().materialize() == j.back());
}
}
CHECK(!v["not a key in the generated documents"]);
CHECK(v.find("not a key in the generated documents") == v.end());
}
else
{
// a primitive is a range of one element; null is empty
CHECK(static_cast<std::size_t>(std::distance(v.begin(), v.end())) == (v.is_null() ? 0u : 1u));
if (!v.is_null())
{
CHECK((*v.begin()).materialize() == j);
CHECK(v.front().materialize() == j);
CHECK(v.back().materialize() == j);
}
}
}
} // namespace
TEST_CASE("json_view element access and iteration")
{
SECTION("generated documents")
{
generator g;
for (int i = 0; i < 2000; ++i)
{
std::string text;
g.value(text, 0);
CAPTURE(text);
const ordered_json_document d = ordered_json_document::parse(text);
check_access(d.root(), ordered_json::parse(text));
}
}
SECTION("keys")
{
// keys of every length around the 2/4/8/16-byte loads, with escapes
std::string text = "{";
std::vector<std::string> keys = {"", "x"};
for (std::size_t n = 1; n <= 40; ++n)
{
keys.emplace_back(n, 'k');
keys.push_back(std::string(n, 'k') + "x");
keys.push_back("x" + std::string(n, 'k'));
}
for (std::size_t i = 0; i < keys.size(); ++i)
{
text += (i != 0 ? ",\"" : "\"") + keys[i] + "\":" + std::to_string(i);
}
text += ",\"esc\\u0061ped\":\"escaped key\"}"; // NOLINT(modernize-raw-string-literal)
const json_document d = json_document::parse(text);
const json_view root = d.root();
for (std::size_t i = 0; i < keys.size(); ++i)
{
CAPTURE(keys[i]);
CHECK(root[keys[i]].materialize() == i);
CHECK(root.at(keys[i]).materialize() == i);
CHECK(root.find(keys[i]).key() == keys[i]);
CHECK(!root.contains(keys[i] + "y"));
}
CHECK(root["escaped"].materialize() == "escaped key");
CHECK(!root.contains("esc\\u0061ped"));
#ifdef JSON_HAS_CPP_17
CHECK(root[std::string_view("kkk")].materialize() == root["kkk"].materialize());
#endif
}
SECTION("duplicate keys: lookups find the first member, iteration all")
{
const json_document d = json_document::parse(R"({"a":1,"b":2,"a":3})");
const json_view v = d.root();
CHECK(v.size() == 3);
CHECK(v["a"].materialize() == 1);
CHECK(v.at("a").materialize() == 1);
CHECK(v.find("a") == v.begin());
CHECK(v.count("a") == 1);
std::string order;
for (auto it = v.begin(); it != v.end(); ++it)
{
order += std::string(it.key().data(), it.key().size()) + it->materialize().dump();
}
CHECK(order == "a1b2a3");
CHECK(v.back().materialize() == 3);
CHECK(v.materialize() == json::parse(R"({"a":1,"b":2,"a":3})")); // the last value, as parse()
}
SECTION("errors are those of const basic_json")
{
for (const char* text :
{"null", "true", "42", "-1", "1.5", "\"s\"", "[]", "[1,2]", "{}", "{\"a\":1}"
})
{
CAPTURE(text);
const json_document d = json_document::parse(text);
const json_view v = d.root();
const json j = v.materialize();
#if !defined(JSON_NOEXCEPTION)
if (!j.is_object())
{
CHECK(exception_of([&] { static_cast<void>(v["a"]); }) == exception_of([&] { static_cast<void>(j["a"]); }));
}
if (!j.is_array())
{
CHECK(exception_of([&] { static_cast<void>(v[0]); }) == exception_of([&] { static_cast<void>(j[0]); }));
}
CHECK(exception_of([&] { static_cast<void>(v.at("a")); }) == exception_of([&] { static_cast<void>(j.at("a")); }));
CHECK(exception_of([&] { static_cast<void>(v.at("missing")); }) == exception_of([&] { static_cast<void>(j.at("missing")); }));
CHECK(exception_of([&] { static_cast<void>(v.at(0)); }) == exception_of([&] { static_cast<void>(j.at(0)); }));
CHECK(exception_of([&] { static_cast<void>(v.at(5)); }) == exception_of([&] { static_cast<void>(j.at(5)); }));
if (!(j.is_object() && j.empty())) // (key() of an end iterator)
{
CHECK(exception_of([&] { static_cast<void>(v.begin().key()); }) == exception_of([&] { static_cast<void>(j.begin().key()); }));
}
if (!j.empty() || j.is_null())
{
CHECK(exception_of([&] { static_cast<void>(v.front()); }) == exception_of([&] { static_cast<void>(j.front()); }));
CHECK(exception_of([&] { static_cast<void>(v.back()); }) == exception_of([&] { static_cast<void>(j.back()); }));
}
#endif
CHECK(v.contains("a") == j.contains("a"));
CHECK(v.count("a") == j.count("a"));
CHECK((v.find("a") == v.end()) == (j.find("a") == j.end())); // NOLINT(readability-container-contains): find() is what is tested
}
// where basic_json has undefined behavior, the view answers safely
const json_document d = json_document::parse(R"({"a":[]})");
CHECK(!d.root()["b"]);
CHECK(!d.root()["a"][0]);
CHECK_THROWS_WITH_AS(d.root()["a"].front(), "[json.exception.invalid_iterator.214] cannot get value", json::invalid_iterator&);
CHECK_THROWS_WITH_AS(d.root()["a"].back(), "[json.exception.invalid_iterator.214] cannot get value", json::invalid_iterator&);
const json_view invalid{};
CHECK(invalid.begin() == invalid.end());
CHECK(std::string(invalid.type_name()) == "discarded");
CHECK_THROWS_WITH_AS(invalid["a"], "[json.exception.type_error.305] cannot use operator[] with a string argument with discarded", json::type_error&);
}
SECTION("iterators")
{
const json_document d = json_document::parse(R"({"x":[1,{"y":2}],"z":null})");
const json_view v = d.root();
json_view::iterator it = v.begin();
CHECK(it.is_object_iterator());
CHECK(it->is_array());
CHECK(it->size() == 2);
const json_view::iterator previous = it++;
CHECK(previous.key() == "x");
CHECK(it.key() == "z");
CHECK(it.value().is_null());
CHECK(++it == v.end());
CHECK(v.cbegin() == v.begin());
CHECK(v.cend() == v.end());
CHECK(!v["x"].begin().is_object_iterator());
CHECK(json_view::iterator() == json_view::iterator());
// standard algorithms
CHECK(std::count_if(v["x"].begin(), v["x"].end(), [](const json_view & e)
{
return e.is_object();
}) == 1);
}
SECTION("items")
{
const json_document d = json_document::parse(R"({"a":1,"b":[true,false]})");
std::string keys;
for (const auto& item : d.root().items())
{
keys += std::string(item.key().data(), item.key().size());
CHECK(item.value().materialize() == d.root()[item.key()].materialize());
}
CHECK(keys == "ab");
auto items = d.root()["b"].items();
auto first = items.begin();
CHECK((*first++).key() == "0");
CHECK((*first).key() == "1");
CHECK(++first == items.end());
#ifdef JSON_HAS_CPP_17
std::string pairs;
for (const auto [key, value] : d.root().items())
{
pairs += std::string(key) + "=" + value.materialize().dump() + ";";
}
CHECK(pairs == "a=1;b=[true,false];");
static_assert(std::tuple_size<json_view::item>::value == 2, "");
static_assert(std::is_same<std::tuple_element<1, json_view::item>::type, json_view>::value, "");
#endif
}
}
namespace
{
#if !defined(JSON_NOEXCEPTION)
// an exception message without the context that basic_json adds with
// JSON_DIAGNOSTICS ("(/path) ") and JSON_DIAGNOSTIC_POSITIONS ("(bytes 1-2) ");
// the view's exceptions have no such context
std::string without_path(std::string msg)
{
for (const char* prefix :
{"] (/", "] (bytes "
})
{
const std::size_t open = msg.find(prefix);
if (open != std::string::npos)
{
msg.erase(open + 2, msg.find(") ", open) + 2 - (open + 2));
}
}
return msg;
}
#endif
// the bits of a float, to compare values bit for bit
std::uint64_t bits(double x)
{
std::uint64_t r = 0;
std::memcpy(&r, &x, sizeof(r));
return r;
}
std::uint32_t bits(float x)
{
std::uint32_t r = 0;
std::memcpy(&r, &x, sizeof(r));
return r;
}
bool has_duplicate_keys(const ordered_json_view& v)
{
if (v.is_object() && v.size() != v.materialize().size())
{
return true;
}
return std::any_of(v.begin(), v.end(), [](const ordered_json_view e)
{
return e.is_structured() && has_duplicate_keys(e);
});
}
// compares the conversions of a view with those of ordered_json
void check_values(const ordered_json_view& v, const ordered_json& j, const std::string& text)
{
CHECK(v.get<ordered_json>() == j);
switch (j.type())
{
case json::value_t::number_integer:
case json::value_t::number_unsigned:
case json::value_t::number_float:
{
// (converting a float out of range of the target type is undefined)
if (j.is_number_unsigned())
{
CHECK(v.get<std::uint64_t>() == j.get<std::uint64_t>());
}
else if (j.is_number_integer())
{
CHECK(v.get<std::int64_t>() == j.get<std::int64_t>());
}
CHECK(bits(v.get<double>()) == bits(j.get<double>()));
if (std::abs(j.get<double>()) < 1e9)
{
CHECK(v.get<int>() == j.get<int>());
}
const auto token = v.number_token();
CHECK(text.compare(v.source_offset(), token.size(), token.data(), token.size()) == 0);
break;
}
case json::value_t::string:
CHECK(v.get<std::string>() == j.get<std::string>());
CHECK(std::string(v.get_string().data(), v.get_string().size()) == j.get<std::string>());
break;
case json::value_t::boolean:
CHECK(v.get<bool>() == j.get<bool>());
CHECK(v.get<int>() == j.get<int>());
break;
case json::value_t::null:
CHECK(v.get<std::nullptr_t>() == nullptr);
break;
case json::value_t::array:
CHECK(v.get<std::vector<ordered_json>>() == j.get<std::vector<ordered_json>>());
break;
case json::value_t::object:
CHECK((v.get<std::map<std::string, ordered_json>>() == j.get<std::map<std::string, ordered_json>>()));
break;
case json::value_t::binary:
case json::value_t::discarded:
default:
break;
}
#if !defined(JSON_NOEXCEPTION)
// conversions to the wrong type throw what basic_json throws
if (!j.is_number())
{
CHECK(exception_of([&] { static_cast<void>(v.get<int>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<int>()); })));
}
CHECK(exception_of([&] { static_cast<void>(v.get<bool>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<bool>()); })));
CHECK(exception_of([&] { static_cast<void>(v.get<std::string>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::string>()); })));
CHECK(exception_of([&] { static_cast<void>(v.get<std::nullptr_t>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::nullptr_t>()); })));
if (!j.is_array())
{
CHECK(exception_of([&] { static_cast<void>(v.get<std::vector<int>>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::vector<int>>()); })));
}
if (!j.is_object())
{
CHECK(exception_of([&] { static_cast<void>(v.get<std::map<std::string, int>>()); }) == without_path(exception_of([&] { static_cast<void>(j.get<std::map<std::string, int>>()); })));
}
#endif
if (v.is_array())
{
std::size_t i = 0;
for (const ordered_json_view e : v)
{
check_values(e, j[i++], text);
}
}
else if (v.is_object())
{
for (auto it = v.begin(); it != v.end(); ++it)
{
const std::string key(it.key().data(), it.key().size());
if (v.size() == j.size()) // (no duplicate keys)
{
check_values(it.value(), j[key], text);
}
}
}
}
struct record
{
std::string name{}; // NOLINT(readability-redundant-member-init)
int count = 0;
};
void from_json(const json& j, record& r)
{
j.at("name").get_to(r.name);
j.at("count").get_to(r.count);
}
} // namespace
TEST_CASE("json_view values")
{
SECTION("generated documents")
{
generator g;
for (int i = 0; i < 2000; ++i)
{
std::string text;
g.value(text, 0);
CAPTURE(text);
const ordered_json_document d = ordered_json_document::parse(text);
check_values(d.root(), ordered_json::parse(text), text);
}
}
SECTION("floats are converted as parse() converts them")
{
std::mt19937_64 rng(5295); // NOLINT(cert-msc32-c,cert-msc51-cpp,bugprone-random-generator-seed)
std::vector<std::string> tokens = {"0.1", "-0.0", "1e308", "1.7976931348623157e308", "2.2250738585072011e-308", "4.9e-324", "5e-324",
"0.1000000000000000055511151231257827021181583404541015625", "123456789012345678901234567890",
"9007199254740993", "1.00000000000000011102230246251565404236316680908203125", "7.2057594037927933e16"
};
for (int i = 0; i < 20000; ++i)
{
const std::uint64_t bits = rng();
double d = 0;
std::memcpy(&d, &bits, sizeof(d));
if (!std::isfinite(d))
{
continue;
}
std::array<char, 400> buf{};
switch (i % 5) // NOLINT(hicpp-multiway-paths-covered)
{
case 0:
std::snprintf(buf.data(), buf.size(), "%.17g", d); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
break;
case 1:
std::snprintf(buf.data(), buf.size(), "%.15g", d); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
break;
case 2:
std::snprintf(buf.data(), buf.size(), "%.3e", d); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
break;
case 3:
std::snprintf(buf.data(), buf.size(), "%.25g", d); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
break;
default:
std::snprintf(buf.data(), buf.size(), "%.0f", d); // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg)
break;
}
tokens.emplace_back(buf.data());
}
using json_float = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t, float>;
for (const auto& token : tokens)
{
CAPTURE(token);
const std::string text = "[" + token + "]";
const double b = json::parse(text)[0].get<double>();
CHECK(bits(json_document::parse(text).root()[0].get<double>()) == bits(b));
if (std::abs(b) < 1e38)
{
CHECK(bits(nlohmann::basic_json_document<json_float>::parse(text).root()[0].get<float>()) == bits(json_float::parse(text)[0].get<float>()));
}
}
}
SECTION("number tokens")
{
const json_document d = json_document::parse(R"([1.50, 1E2, -0, 123456789012345678901234567890, -12, 7, "x"])");
const json_view v = d.root();
CHECK(v[0].number_token() == "1.50");
CHECK(v[1].number_token() == "1E2");
CHECK(v[2].number_token() == "-0");
CHECK(v[3].number_token() == "123456789012345678901234567890");
CHECK(v[4].number_token() == "-12");
CHECK(v[5].number_token() == "7");
CHECK_THROWS_WITH_AS(v[6].number_token(), "[json.exception.type_error.302] type must be number, but is string", json::type_error&);
CHECK_THROWS_WITH_AS(v.get_string(), "[json.exception.type_error.302] type must be string, but is array", json::type_error&);
}
SECTION("conversions")
{
const std::string text = R"({"name": "widget", "count": 3, "tags": ["a", "b\n"], "sizes": {"s": 1, "m": 2}, "pair": [1, "x"]})";
const json_document d = json_document::parse(text);
const json_view v = d.root();
const json j = json::parse(text);
// user types with from_json, and other types, through basic_json
const record r = v.get<record>();
CHECK(r.name == "widget");
CHECK(r.count == 3);
CHECK((v["pair"].get<std::pair<int, std::string>>() == j["pair"].get<std::pair<int, std::string>>()));
CHECK(v["tags"].get<std::list<std::string>>() == j["tags"].get<std::list<std::string>>());
CHECK((v["sizes"].get<std::unordered_map<std::string, int>>() == j["sizes"].get<std::unordered_map<std::string, int>>()));
CHECK(v["tags"].get<std::vector<std::string>>() == std::vector<std::string> {"a", "b\n"});
// views of the elements
const auto views = v["tags"].get<std::vector<json_view>>();
CHECK(views.size() == 2);
CHECK(views[1].get_string() == "b\n");
const auto members = v.get<std::map<std::string, json_view>>();
CHECK(members.at("count").get<int>() == 3);
CHECK(v.get<json_view>()["name"].get_string() == "widget");
// strings without a copy point into the source text
CHECK(v["name"].get_string().data() == text.data() + text.find("widget"));
#ifdef JSON_HAS_CPP_17
CHECK(v["name"].get<std::string_view>() == "widget");
#endif
std::string name;
int count = 0;
CHECK(&v["name"].get_to(name) == &name);
v["count"].get_to(count);
CHECK(name == "widget");
CHECK(count == 3);
// a duplicate key: the last value, as parse()
CHECK((json_document::parse(R"({"a":1,"a":2})").root().get<std::map<std::string, int>>() == std::map<std::string, int> {{"a", 2}}));
const json_view invalid;
CHECK_THROWS_WITH_AS(invalid.get<int>(), "[json.exception.type_error.302] type must be number, but is discarded", json::type_error&);
CHECK(invalid.get<json>().is_discarded());
}
SECTION("value")
{
const json_document d = json_document::parse(R"({"n": 1, "s": "text", "o": {"x": [10, 20]}})");
const json_view v = d.root();
const json j = v.materialize();
CHECK(v.value("n", 0) == j.value("n", 0));
CHECK(v.value("missing", 42) == j.value("missing", 42));
CHECK(v.value("s", "default") == j.value("s", "default"));
CHECK(v.value("missing", "default") == j.value("missing", "default"));
CHECK(v.value(std::string("n"), 2.5) == j.value(std::string("n"), 2.5));
CHECK(v.value(json::json_pointer("/o/x/1"), 0) == j.value(json::json_pointer("/o/x/1"), 0));
CHECK(v.value(json::json_pointer("/o/x/5"), 0) == j.value(json::json_pointer("/o/x/5"), 0));
CHECK(v.value(json::json_pointer("/o/y"), "none") == j.value(json::json_pointer("/o/y"), "none"));
// with a JSON pointer, arrays can be asked as well
CHECK(v["o"]["x"].value(json::json_pointer("/1"), 0) == j["o"]["x"].value(json::json_pointer("/1"), 0));
CHECK(v["o"]["x"].value(json::json_pointer("/7"), 3) == j["o"]["x"].value(json::json_pointer("/7"), 3));
#if !defined(JSON_NOEXCEPTION)
CHECK(exception_of([&] { static_cast<void>(v["o"]["x"].value("k", 0)); }) == without_path(exception_of([&] { static_cast<void>(j["o"]["x"].value("k", 0)); })));
CHECK(exception_of([&] { static_cast<void>(v.value("s", 0)); }) == without_path(exception_of([&] { static_cast<void>(j.value("s", 0)); })));
CHECK(exception_of([&] { static_cast<void>(v["n"].value("x", 0)); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value("x", 0)); })));
CHECK(exception_of([&] { static_cast<void>(v["n"].value(json::json_pointer("/x"), 0)); }) == without_path(exception_of([&] { static_cast<void>(j["n"].value(json::json_pointer("/x"), 0)); })));
#endif
}
}
TEST_CASE("json_view JSON pointers")
{
SECTION("every value of generated documents")
{
generator g;
for (int i = 0; i < 1000; ++i)
{
std::string text;
g.value(text, 0);
const ordered_json_document d = ordered_json_document::parse(text);
if (has_duplicate_keys(d.root()))
{
continue;
}
CAPTURE(text);
const ordered_json j = ordered_json::parse(text);
const ordered_json flat = j.flatten();
for (const auto& leaf : flat.items())
{
// the leaf and each of its parents
for (ordered_json::json_pointer p(leaf.key());; p = p.parent_pointer())
{
CAPTURE(p.to_string());
CHECK(d.root()[p].materialize() == j[p]);
CHECK(d.root().at(p).materialize() == j.at(p));
CHECK(d.root().contains(p));
if (p.empty())
{
break;
}
}
}
}
}
#if !defined(JSON_NOEXCEPTION)
SECTION("errors are those of basic_json")
{
const std::string text = R"({"a": [1, {"b": null}], "c": "s", "": {"": 0}, "a~b": 1, "c/d": 2})";
const json_document d = json_document::parse(text);
const json_view v = d.root();
const json j = v.materialize();
for (const char* pointer :
{"", "/", "//", "/a", "/a/0", "/a/1/b", "/a/-", "/a/01", "/a/00", "/a/1a", "/a/a", "/a/", "/a/2", "/a/99", "/a/99999999999999999999",
"/a/18446744073709551615", "/a/-1", "/a/+1", "/a/ 1", "/x", "/c/x", "/a/0/x", "/a/1/b/c", "/a~0b", "/c~1d", "/c~1d/x", "/a/1/-"
})
{
CAPTURE(pointer);
const json::json_pointer p(pointer);
const std::string at_error = without_path(exception_of([&] { static_cast<void>(j.at(p)); }));
CHECK(exception_of([&] { static_cast<void>(v.at(p)); }) == at_error);
if (at_error.empty())
{
CHECK(v.at(p).materialize() == j.at(p));
CHECK(v[p].materialize() == j[p]);
}
else if (at_error.find("out_of_range.401") != std::string::npos || at_error.find("out_of_range.403") != std::string::npos) // NOLINT(abseil-string-find-str-contains)
{
// undefined behavior for const basic_json::operator[]
CHECK(!v[p]);
}
else
{
CHECK(exception_of([&] { static_cast<void>(v[p]); }) == without_path(exception_of([&] { static_cast<void>(j[p]); })));
}
// (basic_json::contains() throws out_of_range.404 for an empty
// array index token, although it is not meant to throw; the view
// answers false)
const std::string contains_error = exception_of([&]
{
const bool found = j.contains(p);
static_cast<void>(found);
});
CHECK(v.contains(p) == (contains_error.empty() && j.contains(p)));
CHECK(exception_of([&] { static_cast<void>(v.value(p, 5)); }) == without_path(exception_of([&] { static_cast<void>(j.value(p, 5)); })));
}
}
#endif
}
Reference in New Issue View Git Blame Copy Permalink