Fix test failures in the coverage tests

- unit-custom-object-key-type: remove the unused make_strict_key(strict_key)
  overload, the unused range constructor and default constructor, and guard
  data() with JSON_DIAGNOSTICS (unused-function/-member-function errors with
  GCC and clang -Weverything).
- unit-json_view_compare: move the two new sections to the new
  unit-json_view_compare_values.cpp, as the object file got too large for the
  MinGW assembler again, and use a std::map with std::greater instead of
  std::unordered_map, which does not accept the incomplete basic_json
  (clang 3.9, icpc).
- unit-json_view_dump: rename the variables that hid outer ones (MSVC C4456).
- unit-stream-bulk-scan: restore the real size of the oversized get area
  before the adapter is destroyed (JSON_PRECISE_STREAM_POSITION reads the
  character at the read position), and skip the test where the streambuf
  cannot hold a get area larger than an int (MSVC).
- unit-regression1: with JSON_NO_THREAD_LOCAL, copies are built member by
  member and keep correct timestamps, so check the corresponding outcome.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5NasAgbDGG28MqXjQvLqp
Signed-off-by: Claude <noreply@anthropic.com>

tests/src/unit-custom-object-key-type.cpp

@@ -139,20 +139,20 @@ namespace
 class strict_key
 {
   public:
-    strict_key() = default;
-
     strict_key(const char* value)
         : m_value(value)
     {}
 
     strict_key(const std::string& /*value*/) = delete;
 
+#if JSON_DIAGNOSTICS
     // Required by JSON_DIAGNOSTICS, which reads object keys through data()
     // when building the path of an exception.
     const char* data() const noexcept
     {
         return m_value.data();
     }
+#endif
 
     friend bool operator<(const strict_key& lhs, const strict_key& rhs)
     {
@@ -168,11 +168,6 @@ strict_key make_strict_key(const std::string& key)
     return strict_key(key.c_str());
 }
 
-strict_key make_strict_key(const strict_key& key)
-{
-    return key;
-}
-
 template<class Key, class Value, class Compare, class Allocator>
 class strict_object
     : public std::map <
@@ -184,16 +179,6 @@ class strict_object
 {
   public:
     strict_object() = default;
-
-    // the range of another object type, whose keys are made into strict_keys
-    template<class Iterator>
-    strict_object(Iterator first, Iterator last)
-    {
-        for (; first != last; ++first)
-        {
-            this->emplace(make_strict_key(first->first), Value(std::move(first->second)));
-        }
-    }
 };
 
 template<typename T, typename = void>

tests/src/unit-json_view_compare.cpp

@@ -21,22 +21,13 @@ using json_view_test::generator;
 
 #include <array>
 #include <cstddef>
-#include <functional>
 #include <string>
-#include <unordered_map>
 #include <vector>
 
 // These tests were split off unit-json_view_dump.cpp, whose object file got too
 // large for the MinGW assembler ("file too big"). Like that file, this one is
 // also built with C++17, as it mentions JSON_HAS_CPP_17.
 
-namespace
-{
-// an object type without a comparison of keys, and with an arbitrary order of members
-template<typename Key, typename Value, typename /*Compare*/, typename Allocator>
-using unordered_object = std::unordered_map<Key, Value, std::hash<Key>, std::equal_to<Key>, Allocator>;
-} // namespace
-
 TEST_CASE("json_view comparison")
 {
     SECTION("equality of the values parse() produces")
@@ -214,59 +205,6 @@ TEST_CASE("json_view comparison")
         CHECK(!(null_document.root() == discarded));
     }
 
-    SECTION("values that differ in their first bytes, or are written differently")
-    {
-        const auto same = [](const char* x, const char* y)
-        {
-            const json_document dx = json_document::parse(x);
-            const json_document dy = json_document::parse(y);
-            const bool equal = dx.root() == dy.root();
-            CHECK(equal == (json::parse(x) == json::parse(y)));
-            CHECK(equal == (dx.root() == json::parse(y)));
-            const nlohmann::json_editable_document ex = nlohmann::json_editable_document::parse(x);
-            CHECK(equal == (ex.root() == dy.root()));
-            return equal;
-        };
-        // booleans
-        CHECK(!same("true", "false"));
-        CHECK(!same("[true]", "[false]"));
-        CHECK(!same(R"({"a":false,"b":[1]})", R"({"a":true,"b":[1]})"));
-        CHECK(same(R"({"a":true,"b":[1]})", R"({"a":true,"b":[1]})"));
-        // strings and keys of equal length that differ in the first eight bytes (they are compared in words)
-        CHECK(!same(R"("abcdefghijklmnopqrstuvwxyz")", R"("Xbcdefghijklmnopqrstuvwxyz")"));
-        CHECK(!same(R"(["abcdefghijklmnopq",1])", R"(["abcdefghXjklmnopq",1])"));
-        CHECK(!same(R"({"abcdefghijklmnopq":1})", R"({"Xbcdefghijklmnopq":1})"));
-        CHECK(!same(R"({"abcdefghijklmnopq":[1]})", R"({"abcdefghijklmnopX":[1]})"));
-        // floats of one layout and different tokens are the same value
-        CHECK(same("[1.5e0, 2]", "[1.5E0, 2]"));
-        CHECK(same("[1.5e0, 2]", "[1.5e+0, 2]"));
-        CHECK(same("[1.50, 2]", "[1.5, 2]"));
-        CHECK(!same("[1.5e0, 2]", "[1.6e0, 2]"));
-        CHECK(!same("[1.5e0, 2]", "[1.5E1, 2]"));
-        CHECK(same(R"({"a":1.25e0,"b":[3]})", R"({"a":1.25E0,"b":[3]})"));
-    }
-
-    SECTION("a basic_json whose members are not sorted")
-    {
-        // (an object type that is not an ordered map, and does not keep its members sorted either)
-        using unordered_json = nlohmann::basic_json<unordered_object>;
-        using unordered_document = nlohmann::basic_json_document<unordered_json>;
-        std::string text = "{";
-        for (char key = 'a'; key <= 'p'; ++key)
-        {
-            text += (key != 'a' ? ",\"" : "\"") + std::string(1, key) + "\":[" + std::to_string(key) + "]";
-        }
-        text += "}";
-        const unordered_json j = unordered_json::parse(text);
-        const unordered_document d = unordered_document::parse(text);
-        CHECK(d.root() == j);
-        CHECK(j == d.root());
-        unordered_json other = j;
-        other["k"] = 0;
-        CHECK(d.root() != other);
-        CHECK(other != d.root());
-    }
-
     SECTION("values that are the same text, or the same value written differently, at any depth")
     {
         // nested arrays and objects around depths where the walk over equal text gives up

tests/src/unit-json_view_compare_values.cpp

@@ -0,0 +1,83 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  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::json_document;
+
+#include <functional>
+#include <map>
+#include <string>
+
+// These tests were split off unit-json_view_compare.cpp, whose object file got
+// too large for the MinGW assembler ("file too big").
+
+namespace
+{
+// an object type that does not enumerate its members in ascending order of keys
+template<typename Key, typename Value, typename /*Compare*/, typename Allocator>
+using descending_object = std::map<Key, Value, std::greater<Key>, Allocator>;
+} // namespace
+
+TEST_CASE("json_view comparison of differing values")
+{
+    SECTION("values that differ in their first bytes, or are written differently")
+    {
+        const auto same = [](const char* x, const char* y)
+        {
+            const json_document dx = json_document::parse(x);
+            const json_document dy = json_document::parse(y);
+            const bool equal = dx.root() == dy.root();
+            CHECK(equal == (json::parse(x) == json::parse(y)));
+            CHECK(equal == (dx.root() == json::parse(y)));
+            const nlohmann::json_editable_document ex = nlohmann::json_editable_document::parse(x);
+            CHECK(equal == (ex.root() == dy.root()));
+            return equal;
+        };
+        // booleans
+        CHECK(!same("true", "false"));
+        CHECK(!same("[true]", "[false]"));
+        CHECK(!same(R"({"a":false,"b":[1]})", R"({"a":true,"b":[1]})"));
+        CHECK(same(R"({"a":true,"b":[1]})", R"({"a":true,"b":[1]})"));
+        // strings and keys of equal length that differ in the first eight bytes (they are compared in words)
+        CHECK(!same(R"("abcdefghijklmnopqrstuvwxyz")", R"("Xbcdefghijklmnopqrstuvwxyz")"));
+        CHECK(!same(R"(["abcdefghijklmnopq",1])", R"(["abcdefghXjklmnopq",1])"));
+        CHECK(!same(R"({"abcdefghijklmnopq":1})", R"({"Xbcdefghijklmnopq":1})"));
+        CHECK(!same(R"({"abcdefghijklmnopq":[1]})", R"({"abcdefghijklmnopX":[1]})"));
+        // floats of one layout and different tokens are the same value
+        CHECK(same("[1.5e0, 2]", "[1.5E0, 2]"));
+        CHECK(same("[1.5e0, 2]", "[1.5e+0, 2]"));
+        CHECK(same("[1.50, 2]", "[1.5, 2]"));
+        CHECK(!same("[1.5e0, 2]", "[1.6e0, 2]"));
+        CHECK(!same("[1.5e0, 2]", "[1.5E1, 2]"));
+        CHECK(same(R"({"a":1.25e0,"b":[3]})", R"({"a":1.25E0,"b":[3]})"));
+    }
+
+    SECTION("a basic_json whose members are not sorted")
+    {
+        // (an object type that is not an ordered map, and does not keep its members sorted either)
+        using descending_json = nlohmann::basic_json<descending_object>;
+        using descending_document = nlohmann::basic_json_document<descending_json>;
+        std::string text = "{";
+        for (char key = 'a'; key <= 'p'; ++key)
+        {
+            text += (key != 'a' ? ",\"" : "\"") + std::string(1, key) + "\":[" + std::to_string(key) + "]";
+        }
+        text += "}";
+        const descending_json j = descending_json::parse(text);
+        const descending_document d = descending_document::parse(text);
+        CHECK(d.root() == j);
+        CHECK(j == d.root());
+        descending_json other = j;
+        other["k"] = 0;
+        CHECK(d.root() != other);
+        CHECK(other != d.root());
+    }
+}

tests/src/unit-json_view_dump.cpp

@@ -247,15 +247,15 @@ TEST_CASE("json_view dump")
                     })
             {
                 CAPTURE(token)
-                const std::string text = std::string("[") + token + padding + "]";
-                const json_document d = json_document::parse(text);
-                const json j = json::parse(text);
-                CHECK(d.root()[0].get<double>() == j[0].get<double>());
-                CHECK(d.root().dump() == j.dump());
+                const std::string padded = std::string("[") + token + padding + "]";
+                const json_document padded_document = json_document::parse(padded);
+                const json padded_json = json::parse(padded);
+                CHECK(padded_document.root()[0].get<double>() == padded_json[0].get<double>());
+                CHECK(padded_document.root().dump() == padded_json.dump());
                 // a float document converts the tokens as well
                 using json_float = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t, float>;
-                const nlohmann::basic_json_document<json_float> float_doc = nlohmann::basic_json_document<json_float>::parse(text);
-                CHECK(float_doc.root()[0].get<float>() == json_float::parse(text)[0].get<float>());
+                const nlohmann::basic_json_document<json_float> float_doc = nlohmann::basic_json_document<json_float>::parse(padded);
+                CHECK(float_doc.root()[0].get<float>() == json_float::parse(padded)[0].get<float>());
             }
         }
 

tests/src/unit-regression1.cpp

@@ -1553,11 +1553,19 @@ TEST_CASE("regression tests 1")
 
         SECTION("a missing member of an object")
         {
+            my_json j = make();
+#ifdef JSON_NO_THREAD_LOCAL
+            // the objects below the outermost one are not copied by their
+            // object_t here, but member by member, which keeps their
+            // timestamps correct: "c" is not mistaken for "b" and is inserted
+            CHECK(j[my_json::json_pointer("/k/a/c/d")].is_null());
+            CHECK(j["x"]["a"].dump() == R"({"b":1,"c":{"d":null}})");
+#else
             // the timestamp of "c" is that of "b" again, so that emplace()
             // finds the member "b", a number, which has no member "d"
-            my_json j = make();
             CHECK_THROWS_AS(j[my_json::json_pointer("/k/a/c/d")], my_json::out_of_range&);
             CHECK(j["x"]["a"].dump() == R"({"b":1})");
+#endif
         }
 
         SECTION("a null value is converted to an object")

tests/src/unit-stream-bulk-scan.cpp

@@ -109,6 +109,14 @@ class oversized_get_area_streambuf : public std::streambuf
         setg(m_data.data(), m_data.data(), m_data.data() + claimed_size);
     }
 
+    // Give the get area back its real size, so that the adapter may read the
+    // character at the read position when it is destroyed (with
+    // JSON_PRECISE_STREAM_POSITION, it consumes the last character returned).
+    void restore_get_area()
+    {
+        setg(m_data.data(), m_data.data(), m_data.data() + m_data.size());
+    }
+
   private:
     std::array<char, 8> m_data{{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'}};
 };
@@ -458,14 +466,16 @@ TEST_CASE("parsing from a std::istream scans the get area in bulk")
     SECTION("skipping more characters than gbump() takes at once")
     {
         // gbump() takes an int, but a get area can be larger
-        if (sizeof(std::size_t) < 8)
+        const std::size_t claimed = sizeof(std::size_t) < 8 ? 0 : std::size_t{3} << 30u;
+        oversized_get_area_streambuf buf(claimed);
+        if (claimed == 0 || static_cast<std::size_t>(buf.in_avail()) != claimed)
         {
-            MESSAGE("a get area larger than an int needs a 64-bit size_t");
+            // a 32-bit size_t, or a standard library whose streambuf stores
+            // the size of the get area in an int (MSVC)
+            MESSAGE("a get area larger than an int is not supported");
         }
         else
         {
-            const std::size_t claimed = std::size_t{3} << 30u;
-            oversized_get_area_streambuf buf(claimed);
             std::istream is(&buf);
             nlohmann::detail::input_stream_adapter ia(is);
             CHECK(ia.get_character() == 'a');
@@ -477,6 +487,8 @@ TEST_CASE("parsing from a std::istream scans the get area in bulk")
 
             ia.bulk_skip(ia.bulk_remaining());
             CHECK(ia.bulk_remaining() == 0);
+
+            buf.restore_get_area();
         }
     }
 #endif