Add unit tests

Makefile

@@ -159,11 +159,11 @@ pretty:
 	    --preserve-date \
 	    --suffix=none \
 	    --formatted \
-	   $(SRCS) $(AMALGAMATED_FILE) tests/src/*.cpp tests/src/*.hpp tests/benchmarks/src/benchmarks.cpp docs/examples/*.cpp
+	   $(SRCS) $(AMALGAMATED_FILE) tests/src/*.cpp tests/src/*.hpp tests/abi/*.cpp tests/abi/*.hpp tests/benchmarks/src/benchmarks.cpp 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) $(AMALGAMATED_FILE) tests/src/*.cpp tests/src/*.hpp tests/abi/*.cpp tests/abi/*.hpp benchmarks/src/benchmarks.cpp docs/examples/*.cpp; do echo $$FILE; clang-format -i $$FILE; done
 
 # create single header file
 amalgamate: $(AMALGAMATED_FILE)

tests/CMakeLists.txt

@@ -142,6 +142,9 @@ json_test_add_test_for(src/unit-comparison.cpp
     MAIN test_main CXX_STANDARDS ${test_cxx_standards} ${test_force}
 )
 
+# test ABI compatibility
+add_subdirectory(abi)
+
 # *DO NOT* use json_test_set_test_options() below this line
 
 #############################################################################

tests/abi/CMakeLists.txt

@@ -0,0 +1,45 @@
+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 INTERFACE
+    ../thirdparty/doctest
+    include)
+target_link_libraries(abi_compat_common INTERFACE ${NLOHMANN_JSON_TARGET_NAME})
+
+add_library(abi_compat_main STATIC main.cpp)
+target_link_libraries(abi_compat_main PUBLIC abi_compat_common)
+
+add_executable(abi_compat_pre_inline_ns
+    use_v3_10_5.cpp
+    use_this.cpp
+)
+target_link_libraries(abi_compat_pre_inline_ns PRIVATE abi_compat_main)
+add_test(
+    NAME test-abi_compat_pre_inline_ns
+    COMMAND abi_compat_pre_inline_ns ${DOCTEST_TEST_FILTER})
+
+add_library(abi_compat_diag_on STATIC diag_on.cpp)
+target_link_libraries(abi_compat_diag_on PUBLIC abi_compat_common)
+
+add_library(abi_compat_diag_off STATIC diag_off.cpp)
+target_link_libraries(abi_compat_diag_off PUBLIC abi_compat_common)
+
+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.cpp

@@ -0,0 +1,19 @@
+#include "doctest_compatibility.h"
+
+#include "diag.hpp"
+
+TEST_CASE("ABI compatible diagnostics")
+{
+    SECTION("basic_json size")
+    {
+        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")
+    {
+        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.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_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_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"));
+}