Add unit tests

Makefile

@@ -162,11 +162,11 @@ pretty:
 	    --preserve-date \
 	    --suffix=none \
 	    --formatted \
-	   $(SRCS) $(AMALGAMATED_FILE) tests/src/*.cpp tests/src/*.hpp tests/benchmarks/src/benchmarks.cpp docs/examples/*.cpp
+	   $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) docs/examples/*.cpp
 
 # call the Clang-Format on all source files
 pretty_format:
-	for FILE in $(SRCS) $(AMALGAMATED_FILE) tests/src/*.cpp tests/src/*.hpp benchmarks/src/benchmarks.cpp docs/examples/*.cpp; do echo $$FILE; clang-format -i $$FILE; done
+	for FILE in $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) docs/examples/*.cpp; do echo $$FILE; clang-format -i $$FILE; done
 
 # create single header file
 amalgamate: $(AMALGAMATED_FILE)

tests/CMakeLists.txt

@@ -147,6 +147,12 @@ json_test_add_test_for(src/unit-comparison.cpp
 
 # *DO NOT* use json_test_set_test_options() below this line
 
+#############################################################################
+# test ABI compatibility
+#############################################################################
+
+add_subdirectory(abi)
+
 #############################################################################
 # Test the generated build configs
 #############################################################################

tests/abi/CMakeLists.txt

@@ -0,0 +1,29 @@
+# common build settings
+add_library(abi_compat_common INTERFACE)
+target_compile_definitions(abi_compat_common INTERFACE
+    DOCTEST_CONFIG_SUPER_FAST_ASSERTS
+    JSON_TEST_KEEP_MACROS)
+target_compile_features(abi_compat_common INTERFACE cxx_std_11)
+target_compile_options(abi_compat_common INTERFACE
+    $<$<CXX_COMPILER_ID:MSVC>:/EHsc;$<$<CONFIG:Release>:/Od>>
+    # MSVC: Force to always compile with W4
+    $<$<CXX_COMPILER_ID:MSVC>:/W4>
+
+    # https://github.com/nlohmann/json/pull/3229
+    $<$<CXX_COMPILER_ID:Intel>:-diag-disable=2196>
+
+    $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wno-deprecated;-Wno-float-equal>
+    $<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
+    $<$<CXX_COMPILER_ID:Intel>:-diag-disable=1786>)
+target_include_directories(abi_compat_common SYSTEM INTERFACE
+    ../thirdparty/doctest
+    include)
+target_link_libraries(abi_compat_common INTERFACE ${NLOHMANN_JSON_TARGET_NAME})
+
+# shared main()
+add_library(abi_compat_main STATIC main.cpp)
+target_link_libraries(abi_compat_main PUBLIC abi_compat_common)
+
+# add individual tests
+add_subdirectory(diag)
+add_subdirectory(inline_ns)

tests/abi/diag/CMakeLists.txt

@@ -0,0 +1,19 @@
+# test linking library built with different JSON_DIAGNOSTICS setting
+# into the same executable
+
+# compile code using JSON_DIAGNOSTICS=1
+add_library(abi_compat_diag_on STATIC diag_on.cpp)
+target_link_libraries(abi_compat_diag_on PUBLIC abi_compat_common)
+
+# compile code using JSON_DIAGNOSTICS=0
+add_library(abi_compat_diag_off STATIC diag_off.cpp)
+target_link_libraries(abi_compat_diag_off PUBLIC abi_compat_common)
+
+# build test executable and add test
+add_executable(abi_compat_diag diag.cpp)
+target_link_libraries(abi_compat_diag PRIVATE
+    abi_compat_main abi_compat_diag_on abi_compat_diag_off)
+
+add_test(
+    NAME test-abi_compat_diag
+    COMMAND abi_compat_diag ${DOCTEST_TEST_FILTER})

tests/abi/diag/diag.cpp

@@ -0,0 +1,21 @@
+#include "doctest_compatibility.h"
+
+#include "diag.hpp"
+
+TEST_CASE("ABI compatible diagnostics")
+{
+    SECTION("basic_json size")
+    {
+        // basic_json with diagnostics is larger because of added data members
+        CHECK(json_sizeof_diag_on() == json_sizeof_diag_on_explicit());
+        CHECK(json_sizeof_diag_off() == json_sizeof_diag_off_explicit());
+        CHECK(json_sizeof_diag_on() > json_sizeof_diag_off());
+    }
+
+    SECTION("basic_json at")
+    {
+        // accessing a nonexistent key throws different exception with diagnostics
+        CHECK_THROWS_WITH(json_at_diag_on(), "[json.exception.out_of_range.403] (/foo) key 'bar' not found");
+        CHECK_THROWS_WITH(json_at_diag_off(), "[json.exception.out_of_range.403] key 'bar' not found");
+    }
+}

tests/abi/diag/diag.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstddef>
+
+std::size_t json_sizeof_diag_on();
+std::size_t json_sizeof_diag_on_explicit();
+
+std::size_t json_sizeof_diag_off();
+std::size_t json_sizeof_diag_off_explicit();
+
+void json_at_diag_on();
+void json_at_diag_off();

tests/abi/diag/diag_off.cpp

@@ -0,0 +1,22 @@
+#undef JSON_DIAGNOSTICS
+#define JSON_DIAGNOSTICS 0
+#include <nlohmann/json.hpp>
+
+#include "diag.hpp"
+
+std::size_t json_sizeof_diag_off()
+{
+    return sizeof(nlohmann::json);
+}
+
+std::size_t json_sizeof_diag_off_explicit()
+{
+    return sizeof(::NLOHMANN_JSON_NAMESPACE::json);
+}
+
+void json_at_diag_off()
+{
+    using nlohmann::json;
+    json j = json{{"foo", json::object()}};
+    j.at(json::json_pointer("/foo/bar"));
+}

tests/abi/diag/diag_on.cpp

@@ -0,0 +1,22 @@
+#undef JSON_DIAGNOSTICS
+#define JSON_DIAGNOSTICS 1
+#include <nlohmann/json.hpp>
+
+#include "diag.hpp"
+
+std::size_t json_sizeof_diag_on()
+{
+    return sizeof(nlohmann::json);
+}
+
+std::size_t json_sizeof_diag_on_explicit()
+{
+    return sizeof(::NLOHMANN_JSON_NAMESPACE::json);
+}
+
+void json_at_diag_on()
+{
+    using nlohmann::json;
+    json j = json{{"foo", json::object()}};
+    j.at(json::json_pointer("/foo/bar"));
+}

tests/abi/inline_ns/CMakeLists.txt

@@ -0,0 +1,12 @@
+# test linking an old library version without an inline namespace
+# with the current library using an inline namespace into the same executable
+
+# build test executable and add test
+add_executable(abi_compat_inline_ns
+    use_v3_10_5.cpp
+    use_current.cpp)
+target_link_libraries(abi_compat_inline_ns PRIVATE abi_compat_main)
+
+add_test(
+    NAME test-abi_compat_inline_ns
+    COMMAND abi_compat_inline_ns ${DOCTEST_TEST_FILTER})

tests/abi/inline_ns/use_current.cpp

@@ -0,0 +1,28 @@
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+
+TEST_CASE("use current library with inline namespace")
+{
+    SECTION("implicitly")
+    {
+        using nlohmann::json;
+        using nlohmann::ordered_json;
+
+        json j;
+        // In v3.10.5 mixing json_pointers of different basic_json types
+        // results in implicit string conversion
+        j[ordered_json::json_pointer("/root")] = json::object();
+        CHECK(j.dump() == "{\"root\":{}}");
+    }
+
+    SECTION("explicitly")
+    {
+        using NLOHMANN_JSON_NAMESPACE::json;
+        using NLOHMANN_JSON_NAMESPACE::ordered_json;
+
+        json j;
+        j[ordered_json::json_pointer("/root")] = json::object();
+        CHECK(j.dump() == "{\"root\":{}}");
+    }
+}

tests/abi/inline_ns/use_v3_10_5.cpp

@@ -0,0 +1,14 @@
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json_v3_10_5.hpp>
+using nlohmann::json;
+using nlohmann::ordered_json;
+
+TEST_CASE("use library v3.10.5 without inline namespace")
+{
+    json j;
+    j[ordered_json::json_pointer("/root")] = json::object();
+    // In v3.10.5 mixing json_pointers of different basic_json types
+    // results in implicit string conversion
+    CHECK(j.dump() == "{\"/root\":{}}");
+}

tests/abi/main.cpp

@@ -0,0 +1,31 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.10.5
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2022 Niels Lohmann <http://nlohmann.me>.
+
+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.
+*/
+
+#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
+#include "doctest_compatibility.h"