1 files changed, 99 insertions, 0 deletions
diff --git a/json4cpp/tests/src/unit-wstring.cpp b/json4cpp/tests/src/unit-wstring.cpp
new file mode 100644
index 0000000000..dec9c1f9a7
--- /dev/null
+++ b/json4cpp/tests/src/unit-wstring.cpp
@@ -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
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+// ICPC errors out on multibyte character sequences in source files
+#ifndef __INTEL_COMPILER
+namespace
+{
+bool wstring_is_utf16();
+bool wstring_is_utf16()
+{
+    return (std::wstring(L"💩") == std::wstring(L"\U0001F4A9"));
+}
+
+bool u16string_is_utf16();
+bool u16string_is_utf16()
+{
+    return (std::u16string(u"💩") == std::u16string(u"\U0001F4A9"));
+}
+
+bool u32string_is_utf32();
+bool u32string_is_utf32()
+{
+    return (std::u32string(U"💩") == std::u32string(U"\U0001F4A9"));
+}
+} // namespace
+
+TEST_CASE("wide strings")
+{
+    SECTION("std::wstring")
+    {
+        if (wstring_is_utf16())
+        {
+            std::wstring const w = L"[12.2,\"Ⴥaäö💤🧢\"]";
+            json const j = json::parse(w);
+            CHECK(j.dump() == "[12.2,\"Ⴥaäö💤🧢\"]");
+        }
+    }
+
+    SECTION("invalid std::wstring")
+    {
+        if (wstring_is_utf16())
+        {
+            std::wstring const w = L"\"\xDBFF";
+            json _;
+            CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
+        }
+    }
+
+    SECTION("std::u16string")
+    {
+        if (u16string_is_utf16())
+        {
+            std::u16string const w = u"[12.2,\"Ⴥaäö💤🧢\"]";
+            json const j = json::parse(w);
+            CHECK(j.dump() == "[12.2,\"Ⴥaäö💤🧢\"]");
+        }
+    }
+
+    SECTION("invalid std::u16string")
+    {
+        if (wstring_is_utf16())
+        {
+            std::u16string const w = u"\"\xDBFF";
+            json _;
+            CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
+        }
+    }
+
+    SECTION("std::u32string")
+    {
+        if (u32string_is_utf32())
+        {
+            std::u32string const w = U"[12.2,\"Ⴥaäö💤🧢\"]";
+            json const j = json::parse(w);
+            CHECK(j.dump() == "[12.2,\"Ⴥaäö💤🧢\"]");
+        }
+    }
+
+    SECTION("invalid std::u32string")
+    {
+        if (u32string_is_utf32())
+        {
+            std::u32string const w = U"\"\x110000";
+            json _;
+            CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
+        }
+    }
+}
+#endif