michael@0: function run_test() {
michael@0:   var Cu = Components.utils;
michael@0:   sb = new Cu.Sandbox('http://www.example.com',
michael@0:                       { wantGlobalProperties: ["TextDecoder", "TextEncoder"] });
michael@0:   sb.do_check_eq = do_check_eq;
michael@0:   Cu.evalInSandbox('do_check_eq(new TextDecoder().encoding, "utf-8");' +
michael@0:                    'do_check_eq(new TextEncoder().encoding, "utf-8");',
michael@0:                    sb);
michael@0:   Cu.importGlobalProperties(["TextDecoder", "TextEncoder"]);
michael@0:   do_check_eq(new TextDecoder().encoding, "utf-8");
michael@0:   do_check_eq(new TextEncoder().encoding, "utf-8");
michael@0: }