gecko-dev/services/sync/tests/unit/test_utils_lazy2.js

37 строки
1.0 KiB
JavaScript

_("Make sure lazy2 function calling/assignment works");
Cu.import("resource://services-sync/util.js");
function run_test() {
let count = 0;
let Foo = function() {
return ++count;
}
_("Make a thing instance of Foo but make sure it isn't initialized yet");
let obj = {};
Utils.lazy2(obj, "thing", Foo);
do_check_eq(count, 0);
_("Access the property to make it evaluates");
do_check_eq(typeof obj.thing, "number");
do_check_eq(count, 1);
do_check_eq(obj.thing, 1);
_("Additional accesses don't evaluate again (nothing should change");
do_check_eq(typeof obj.thing, "number");
do_check_eq(count, 1);
do_check_eq(obj.thing, 1);
_("More lazy properties will constrct more");
do_check_eq(typeof obj.other, "undefined");
Utils.lazy2(obj, "other", Foo);
do_check_eq(typeof obj.other, "number");
do_check_eq(count, 2);
do_check_eq(obj.other, 2);
_("Sanity check that the original property didn't change");
do_check_eq(typeof obj.thing, "number");
do_check_eq(count, 2);
do_check_eq(obj.thing, 1);
}