:white_check_mark: add regression test

test/src/unit-regression2.cpp

diff --git a/test/src/unit-regression2.cpp b/test/src/unit-regression2.cpp
index 86320f0..1e8c492 100644
--- a/test/src/unit-regression2.cpp
+++ b/test/src/unit-regression2.cpp
@@ -495,7 +495,7 @@
         const char DATA[] = R"("Hello, world!")";
         const auto s = std::as_bytes(std::span(DATA));
         json j = json::parse(s);
-        CHECK(j.dump() == "Hello, world!");
+        CHECK(j.dump() == "\"Hello, world!\"");
     }
 #endif
 }