diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/JSON/stringify-primitives.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/JSON/stringify-primitives.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,41 @@
+// Ported from dom/src/json/test/unit/test_encode_primitives.js
+
+// sanity
+var x = JSON.stringify({});
+assertEq(x, "{}");
+
+// booleans and null
+x = JSON.stringify(true);
+assertEq(x, "true");
+
+x = JSON.stringify(false);
+assertEq(x, "false");
+
+x = JSON.stringify(new Boolean(false));
+assertEq(x, "false");
+
+x = JSON.stringify(null);
+assertEq(x, "null");
+
+x = JSON.stringify(1234);
+assertEq(x, "1234");
+
+x = JSON.stringify(new Number(1234));
+assertEq(x, "1234");
+
+x = JSON.stringify("asdf");
+assertEq(x, '"asdf"');
+
+x = JSON.stringify(new String("asdf"));
+assertEq(x, '"asdf"');
+
+assertEq(JSON.stringify(undefined), undefined);
+assertEq(JSON.stringify(function(){}), undefined);
+assertEq(JSON.stringify(JSON.stringify), undefined);
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");