The Tor Browser / file revision

 // Order of Array.of operations.

 load(libdir + "asserts.js");

 var log;

 var dstdata = [];

 var dst = new Proxy(dstdata, {

     defineProperty: function (t, name, desc) {

         log.push(["def", name, desc.value]);

     },

     set: function (t, name, value) {

         log.push(["set", name, value]);

     }

 });

 function Troop() {

     return dst;

 }

 Troop.of = Array.of;

 log = [];

 assertEq(Troop.of("monkeys", "baboons", "kangaroos"), dst);

 assertDeepEq(log, [

     ["def", "0", "monkeys"],

     ["def", "1", "baboons"],

     ["def", "2", "kangaroos"],

     ["set", "length", 3]

 ]);