diff --git a/tests/src/sax_countdown.hpp b/tests/src/sax_countdown.hpp
new file mode 100644
index 000000000..a4e80c90c
--- /dev/null
+++ b/tests/src/sax_countdown.hpp
@@ -0,0 +1,99 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  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
+
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include <nlohmann/json.hpp>
+
+namespace utils
+{
+/// a SAX event consumer that stops accepting events after a fixed count,
+/// used by the binary-format tests to check behavior when the SAX consumer
+/// rejects an event partway through parsing
+class SaxCountdown
+{
+  public:
+    using json = nlohmann::json;
+
+    explicit SaxCountdown(const int count) : events_left(count)
+    {}
+
+    bool null()
+    {
+        return events_left-- > 0;
+    }
+
+    bool boolean(bool /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool number_integer(json::number_integer_t /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool number_unsigned(json::number_unsigned_t /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool string(std::string& /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool binary(std::vector<std::uint8_t>& /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool start_object(std::size_t /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool key(std::string& /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool end_object()
+    {
+        return events_left-- > 0;
+    }
+
+    bool start_array(std::size_t /*unused*/)
+    {
+        return events_left-- > 0;
+    }
+
+    bool end_array()
+    {
+        return events_left-- > 0;
+    }
+
+    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
+    {
+        return false;
+    }
+
+  private:
+    int events_left = 0;
+};
+} // namespace utils
diff --git a/tests/src/unit-32bit.cpp b/tests/src/unit-32bit.cpp
index aead04205..97549c999 100644
--- a/tests/src/unit-32bit.cpp
+++ b/tests/src/unit-32bit.cpp
@@ -12,80 +12,11 @@
 using nlohmann::json;
 
 #include <climits> // SIZE_MAX
-#include <limits> // numeric_limits
 
-template <typename OfType, typename T, bool MinInRange, bool MaxInRange>
-struct trait_test_arg
-{
-    using of_type = OfType;
-    using type = T;
-    static constexpr bool min_in_range = MinInRange;
-    static constexpr bool max_in_range = MaxInRange;
-};
-
-TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test) // NOLINT(readability-math-missing-parentheses)
-{
-    using nlohmann::detail::value_in_range_of;
-
-    using of_type = typename T::of_type;
-    using type = typename T::type;
-    constexpr bool min_in_range = T::min_in_range;
-    constexpr bool max_in_range = T::max_in_range;
-
-    type const val_min = std::numeric_limits<type>::min();
-    type const val_min2 = val_min + 1;
-    type const val_max = std::numeric_limits<type>::max();
-    type const val_max2 = val_max - 1;
-
-    REQUIRE(CHAR_BIT == 8);
-
-    std::string of_type_str;
-    if (std::is_unsigned<of_type>::value)
-    {
-        of_type_str += "u";
-    }
-    of_type_str += "int";
-    of_type_str += std::to_string(sizeof(of_type) * 8);
-
-    INFO("of_type := ", of_type_str);
-
-    std::string type_str;
-    if (std::is_unsigned<type>::value)
-    {
-        type_str += "u";
-    }
-    type_str += "int";
-    type_str += std::to_string(sizeof(type) * 8);
-
-    INFO("type := ", type_str);
-
-    CAPTURE(val_min);
-    CAPTURE(min_in_range);
-    CAPTURE(val_max);
-    CAPTURE(max_in_range);
-
-    if (min_in_range)
-    {
-        CHECK(value_in_range_of<of_type>(val_min));
-        CHECK(value_in_range_of<of_type>(val_min2));
-    }
-    else
-    {
-        CHECK_FALSE(value_in_range_of<of_type>(val_min));
-        CHECK_FALSE(value_in_range_of<of_type>(val_min2));
-    }
-
-    if (max_in_range)
-    {
-        CHECK(value_in_range_of<of_type>(val_max));
-        CHECK(value_in_range_of<of_type>(val_max2));
-    }
-    else
-    {
-        CHECK_FALSE(value_in_range_of<of_type>(val_max));
-        CHECK_FALSE(value_in_range_of<of_type>(val_max2));
-    }
-}
+// JSON_32bitTest=ONLY builds only this file, so it must keep its own
+// include of the shared trait/TEST_CASE_TEMPLATE_DEFINE rather than relying
+// on unit-bjdata.cpp to provide it
+#include "value_in_range_of_test.hpp"
 
 TEST_CASE("32bit")
 {
diff --git a/tests/src/unit-bjdata.cpp b/tests/src/unit-bjdata.cpp
index a58507c15..f6e646c50 100644
--- a/tests/src/unit-bjdata.cpp
+++ b/tests/src/unit-bjdata.cpp
@@ -21,158 +21,13 @@ using nlohmann::json;
 #include "make_test_data_available.hpp"
 #include "round_trip_corpus.hpp"
 #include "test_utils.hpp"
+#include "sax_countdown.hpp"
+using utils::SaxCountdown;
 
-namespace
-{
-class SaxCountdown
-{
-  public:
-    explicit SaxCountdown(const int count) : events_left(count)
-    {}
 
-    bool null()
-    {
-        return events_left-- > 0;
-    }
-
-    bool boolean(bool /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_integer(json::number_integer_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_unsigned(json::number_unsigned_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool string(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool binary(std::vector<std::uint8_t>& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_object(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool key(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_object()
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_array(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_array()
-    {
-        return events_left-- > 0;
-    }
-
-    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
-    {
-        return false;
-    }
-
-  private:
-    int events_left = 0;
-};
-} // namespace
-
-// at some point in the future, a unit test dedicated to type traits might be a good idea
-template <typename OfType, typename T, bool MinInRange, bool MaxInRange>
-struct trait_test_arg
-{
-    using of_type = OfType;
-    using type = T;
-    static constexpr bool min_in_range = MinInRange;
-    static constexpr bool max_in_range = MaxInRange;
-};
-
-TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test) // NOLINT(readability-math-missing-parentheses)
-{
-    using nlohmann::detail::value_in_range_of;
-
-    using of_type = typename T::of_type;
-    using type = typename T::type;
-    constexpr bool min_in_range = T::min_in_range;
-    constexpr bool max_in_range = T::max_in_range;
-
-    type const val_min = std::numeric_limits<type>::min();
-    type const val_min2 = val_min + 1;
-    type const val_max = std::numeric_limits<type>::max();
-    type const val_max2 = val_max - 1;
-
-    REQUIRE(CHAR_BIT == 8);
-
-    std::string of_type_str;
-    if (std::is_unsigned<of_type>::value)
-    {
-        of_type_str += "u";
-    }
-    of_type_str += "int";
-    of_type_str += std::to_string(sizeof(of_type) * 8);
-
-    INFO("of_type := ", of_type_str);
-
-    std::string type_str;
-    if (std::is_unsigned<type>::value)
-    {
-        type_str += "u";
-    }
-    type_str += "int";
-    type_str += std::to_string(sizeof(type) * 8);
-
-    INFO("type := ", type_str);
-
-    CAPTURE(val_min);
-    CAPTURE(min_in_range);
-    CAPTURE(val_max);
-    CAPTURE(max_in_range);
-
-    if (min_in_range)
-    {
-        CHECK(value_in_range_of<of_type>(val_min));
-        CHECK(value_in_range_of<of_type>(val_min2));
-    }
-    else
-    {
-        CHECK_FALSE(value_in_range_of<of_type>(val_min));
-        CHECK_FALSE(value_in_range_of<of_type>(val_min2));
-    }
-
-    if (max_in_range)
-    {
-        CHECK(value_in_range_of<of_type>(val_max));
-        CHECK(value_in_range_of<of_type>(val_max2));
-    }
-    else
-    {
-        CHECK_FALSE(value_in_range_of<of_type>(val_max));
-        CHECK_FALSE(value_in_range_of<of_type>(val_max2));
-    }
-}
+// trait_test_arg and the "value_in_range_of trait" TEST_CASE_TEMPLATE_DEFINE
+// are shared with unit-32bit.cpp
+#include "value_in_range_of_test.hpp"
 
 // NOLINTNEXTLINE(bugprone-throwing-static-initialization)
 TEST_CASE_TEMPLATE_INVOKE(value_in_range_of_test, \
diff --git a/tests/src/unit-bon8.cpp b/tests/src/unit-bon8.cpp
index 030e1d5c3..c2aeb3db8 100644
--- a/tests/src/unit-bon8.cpp
+++ b/tests/src/unit-bon8.cpp
@@ -22,84 +22,11 @@ using nlohmann::json;
 #include <vector>
 #include "make_test_data_available.hpp"
 #include "test_utils.hpp"
+#include "sax_countdown.hpp"
+using utils::SaxCountdown;
 
 namespace
 {
-class SaxCountdown
-{
-  public:
-    explicit SaxCountdown(const int count) : events_left(count)
-    {}
-
-    bool null()
-    {
-        return events_left-- > 0;
-    }
-
-    bool boolean(bool /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_integer(json::number_integer_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_unsigned(json::number_unsigned_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool string(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool binary(std::vector<std::uint8_t>& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_object(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool key(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_object()
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_array(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_array()
-    {
-        return events_left-- > 0;
-    }
-
-    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
-    {
-        return false;
-    }
-
-  private:
-    int events_left = 0;
-};
-
 using bytes = std::vector<std::uint8_t>;
 
 /// @return the string with the given bytes
diff --git a/tests/src/unit-bson.cpp b/tests/src/unit-bson.cpp
index 292ff4dc1..7652a21b3 100644
--- a/tests/src/unit-bson.cpp
+++ b/tests/src/unit-bson.cpp
@@ -18,6 +18,8 @@ using nlohmann::json;
 #include <vector>
 #include "make_test_data_available.hpp"
 #include "test_utils.hpp"
+#include "sax_countdown.hpp"
+using utils::SaxCountdown;
 
 namespace
 {
@@ -857,83 +859,6 @@ TEST_CASE("BSON input/output_adapters")
     }
 }
 
-namespace
-{
-class SaxCountdown
-{
-  public:
-    explicit SaxCountdown(const int count) : events_left(count)
-    {}
-
-    bool null()
-    {
-        return events_left-- > 0;
-    }
-
-    bool boolean(bool /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_integer(json::number_integer_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_unsigned(json::number_unsigned_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool string(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool binary(std::vector<std::uint8_t>& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_object(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool key(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_object()
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_array(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_array()
-    {
-        return events_left-- > 0;
-    }
-
-    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
-    {
-        return false;
-    }
-
-  private:
-    int events_left = 0;
-};
-} // namespace
 
 TEST_CASE("Incomplete BSON Input")
 {
diff --git a/tests/src/unit-cbor.cpp b/tests/src/unit-cbor.cpp
index bdd9a98f1..e76e28b5c 100644
--- a/tests/src/unit-cbor.cpp
+++ b/tests/src/unit-cbor.cpp
@@ -19,84 +19,9 @@ using nlohmann::json;
 #include <set>
 #include "make_test_data_available.hpp"
 #include "test_utils.hpp"
+#include "sax_countdown.hpp"
+using utils::SaxCountdown;
 
-namespace
-{
-class SaxCountdown
-{
-  public:
-    explicit SaxCountdown(const int count) : events_left(count)
-    {}
-
-    bool null()
-    {
-        return events_left-- > 0;
-    }
-
-    bool boolean(bool /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_integer(json::number_integer_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_unsigned(json::number_unsigned_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool string(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool binary(std::vector<std::uint8_t>& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_object(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool key(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_object()
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_array(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_array()
-    {
-        return events_left-- > 0;
-    }
-
-    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
-    {
-        return false;
-    }
-
-  private:
-    int events_left = 0;
-};
-} // namespace
 
 TEST_CASE("CBOR")
 {
diff --git a/tests/src/unit-msgpack.cpp b/tests/src/unit-msgpack.cpp
index 498dec859..ae7b458a9 100644
--- a/tests/src/unit-msgpack.cpp
+++ b/tests/src/unit-msgpack.cpp
@@ -22,84 +22,9 @@ using nlohmann::json;
 #include <set>
 #include "make_test_data_available.hpp"
 #include "test_utils.hpp"
+#include "sax_countdown.hpp"
+using utils::SaxCountdown;
 
-namespace
-{
-class SaxCountdown
-{
-  public:
-    explicit SaxCountdown(const int count) : events_left(count)
-    {}
-
-    bool null()
-    {
-        return events_left-- > 0;
-    }
-
-    bool boolean(bool /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_integer(json::number_integer_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_unsigned(json::number_unsigned_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool string(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool binary(std::vector<std::uint8_t>& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_object(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool key(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_object()
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_array(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_array()
-    {
-        return events_left-- > 0;
-    }
-
-    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
-    {
-        return false;
-    }
-
-  private:
-    int events_left = 0;
-};
-} // namespace
 
 TEST_CASE("MessagePack")
 {
diff --git a/tests/src/unit-regression2.cpp b/tests/src/unit-regression2.cpp
index c466958bf..ff870123f 100644
--- a/tests/src/unit-regression2.cpp
+++ b/tests/src/unit-regression2.cpp
@@ -199,28 +199,6 @@ struct adl_serializer<NonDefaultConstructible>
 };
 }  // namespace nlohmann
 
-/////////////////////////////////////////////////////////////////////
-// for #2824
-/////////////////////////////////////////////////////////////////////
-
-class sax_no_exception : public nlohmann::detail::json_sax_dom_parser<json, nlohmann::detail::string_input_adapter_type>
-{
-  public:
-    explicit sax_no_exception(json& j)
-        : nlohmann::detail::json_sax_dom_parser<json, nlohmann::detail::string_input_adapter_type>(j, false)
-    {}
-
-    static bool parse_error(std::size_t /*position*/, const std::string& /*last_token*/, const json::exception& ex)
-    {
-        error_string = new std::string(ex.what());  // NOLINT(cppcoreguidelines-owning-memory)
-        return false;
-    }
-
-    static std::string* error_string;
-};
-
-std::string* sax_no_exception::error_string = nullptr;
-
 /////////////////////////////////////////////////////////////////////
 // for #2982
 /////////////////////////////////////////////////////////////////////
@@ -723,16 +701,6 @@ TEST_CASE("regression tests 2")
         }
     }
 
-    SECTION("issue #2824 - encoding of json::exception::what()")
-    {
-        json j;
-        sax_no_exception sax(j);
-
-        CHECK(!json::sax_parse("xyz", &sax));
-        CHECK(*sax_no_exception::error_string == "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - invalid literal; last read: 'x'");
-        delete sax_no_exception::error_string;  // NOLINT(cppcoreguidelines-owning-memory)
-    }
-
     SECTION("issue #2825 - Properly constrain the basic_json conversion operator")
     {
         static_assert(std::is_copy_assignable<nlohmann::ordered_json>::value, "ordered_json must be copy assignable");
diff --git a/tests/src/unit-ubjson.cpp b/tests/src/unit-ubjson.cpp
index c315fac94..87ff78d36 100644
--- a/tests/src/unit-ubjson.cpp
+++ b/tests/src/unit-ubjson.cpp
@@ -17,84 +17,9 @@ using nlohmann::json;
 #include "make_test_data_available.hpp"
 #include "round_trip_corpus.hpp"
 #include "test_utils.hpp"
+#include "sax_countdown.hpp"
+using utils::SaxCountdown;
 
-namespace
-{
-class SaxCountdown
-{
-  public:
-    explicit SaxCountdown(const int count) : events_left(count)
-    {}
-
-    bool null()
-    {
-        return events_left-- > 0;
-    }
-
-    bool boolean(bool /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_integer(json::number_integer_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_unsigned(json::number_unsigned_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool number_float(json::number_float_t /*unused*/, const std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool string(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool binary(std::vector<std::uint8_t>& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_object(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool key(std::string& /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_object()
-    {
-        return events_left-- > 0;
-    }
-
-    bool start_array(std::size_t /*unused*/)
-    {
-        return events_left-- > 0;
-    }
-
-    bool end_array()
-    {
-        return events_left-- > 0;
-    }
-
-    bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const json::exception& /*unused*/) // NOLINT(readability-convert-member-functions-to-static)
-    {
-        return false;
-    }
-
-  private:
-    int events_left = 0;
-};
-} // namespace
 
 TEST_CASE("UBJSON")
 {
diff --git a/tests/src/value_in_range_of_test.hpp b/tests/src/value_in_range_of_test.hpp
new file mode 100644
index 000000000..067aef41b
--- /dev/null
+++ b/tests/src/value_in_range_of_test.hpp
@@ -0,0 +1,92 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  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
+
+#pragma once
+
+// shared between unit-32bit.cpp (which must keep including this header,
+// because JSON_32bitTest=ONLY builds only that file) and unit-bjdata.cpp
+
+#include <climits> // CHAR_BIT
+#include <limits>
+#include <string>
+#include <type_traits>
+
+#include <nlohmann/json.hpp>
+
+template <typename OfType, typename T, bool MinInRange, bool MaxInRange>
+struct trait_test_arg
+{
+    using of_type = OfType;
+    using type = T;
+    static constexpr bool min_in_range = MinInRange;
+    static constexpr bool max_in_range = MaxInRange;
+};
+
+TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test) // NOLINT(readability-math-missing-parentheses)
+{
+    using nlohmann::detail::value_in_range_of;
+
+    using of_type = typename T::of_type;
+    using type = typename T::type;
+    constexpr bool min_in_range = T::min_in_range;
+    constexpr bool max_in_range = T::max_in_range;
+
+    type const val_min = std::numeric_limits<type>::min();
+    type const val_min2 = val_min + 1;
+    type const val_max = std::numeric_limits<type>::max();
+    type const val_max2 = val_max - 1;
+
+    REQUIRE(CHAR_BIT == 8);
+
+    std::string of_type_str;
+    if (std::is_unsigned<of_type>::value)
+    {
+        of_type_str += "u";
+    }
+    of_type_str += "int";
+    of_type_str += std::to_string(sizeof(of_type) * 8);
+
+    INFO("of_type := ", of_type_str);
+
+    std::string type_str;
+    if (std::is_unsigned<type>::value)
+    {
+        type_str += "u";
+    }
+    type_str += "int";
+    type_str += std::to_string(sizeof(type) * 8);
+
+    INFO("type := ", type_str);
+
+    CAPTURE(val_min);
+    CAPTURE(min_in_range);
+    CAPTURE(val_max);
+    CAPTURE(max_in_range);
+
+    if (min_in_range)
+    {
+        CHECK(value_in_range_of<of_type>(val_min));
+        CHECK(value_in_range_of<of_type>(val_min2));
+    }
+    else
+    {
+        CHECK_FALSE(value_in_range_of<of_type>(val_min));
+        CHECK_FALSE(value_in_range_of<of_type>(val_min2));
+    }
+
+    if (max_in_range)
+    {
+        CHECK(value_in_range_of<of_type>(val_max));
+        CHECK(value_in_range_of<of_type>(val_max2));
+    }
+    else
+    {
+        CHECK_FALSE(value_in_range_of<of_type>(val_max));
+        CHECK_FALSE(value_in_range_of<of_type>(val_max2));
+    }
+}