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 _("Make sure various combinations of deferGetSet arguments correctly defer getting/setting properties to another object");

 Cu.import("resource://services-sync/util.js");

 function run_test() {

   let base = function() {};

   base.prototype = {

     dst: {},

     get a() "a",

     set b(val) this.dst.b = val + "!!!"

   };

   let src = new base();

   _("get/set a single property");

   Utils.deferGetSet(base, "dst", "foo");

   src.foo = "bar";

   do_check_eq(src.dst.foo, "bar");

   do_check_eq(src.foo, "bar");

   _("editing the target also updates the source");

   src.dst.foo = "baz";

   do_check_eq(src.dst.foo, "baz");

   do_check_eq(src.foo, "baz");

   _("handle multiple properties");

   Utils.deferGetSet(base, "dst", ["p1", "p2"]);

   src.p1 = "v1";

   src.p2 = "v2";

   do_check_eq(src.p1, "v1");

   do_check_eq(src.dst.p1, "v1");

   do_check_eq(src.p2, "v2");

   do_check_eq(src.dst.p2, "v2");

   _("make sure existing getter keeps its functionality");

   Utils.deferGetSet(base, "dst", "a");

   src.a = "not a";

   do_check_eq(src.dst.a, "not a");

   do_check_eq(src.a, "a");

   _("make sure existing setter keeps its functionality");

   Utils.deferGetSet(base, "dst", "b");

   src.b = "b";

   do_check_eq(src.dst.b, "b!!!");

   do_check_eq(src.b, "b!!!");

 }