fix: handle empty null-prototyped objects (#5506)

Co-authored-by: alxndrsn <alxndrsn>
Co-authored-by: Mark Wiemer <[email protected]>

Author: alxndrsn

lib/utils.js

@@ -108,6 +108,7 @@ function emptyRepresentation(value, typeHint) {
   switch (typeHint) {
     case "function":
       return "[Function]";
+    case "null-prototype":
     case "object":
       return "{}";
     case "array":

test/unit/utils.spec.js

@@ -290,6 +290,13 @@ describe("lib/utils", function () {
       });
 
       describe("should represent null prototypes", function () {
+        it("Without properties", function () {
+          const foo = Object.create(null, {});
+          const expected = "{}";
+
+          expect(stringify(foo), "to be", expected);
+        });
+
         it("With explicit names", function () {
           const foo = Object.create(null, {
             [Symbol.toStringTag]: { value: "Foo" },