The Tor Browser / file revision

 // obj.getOwnPropertyDescriptor works on global objects.

 var g = newGlobal();

 g.eval("var v; const k = 42;");

 this.eval("var v; const k = 42;");

 var dbg = Debugger();

 var obj = dbg.addDebuggee(g);

 function test(name) {

     var desc = obj.getOwnPropertyDescriptor(name);

     assertEq(desc instanceof Object, true);

     var expected = Object.getOwnPropertyDescriptor(this, name);

     assertEq(Object.prototype.toString.call(desc), Object.prototype.toString.call(expected));

     assertEq(desc.enumerable, expected.enumerable);

     assertEq(desc.configurable, expected.configurable);

     assertEq(desc.writable, expected.writable);

     assertEq(desc.value, expected.value);

 }

 test("Infinity");

 test("v");

 test("k");