this.EXPORTED_SYMBOLS = ['checkFromJSM']; this.checkFromJSM = function checkFromJSM(target, is_op) { is_op(target.numProp, 42, "Number expando works"); is_op(target.strProp, "foo", "String expando works"); // If is_op is todo_is, target.objProp will be undefined. try { is_op(target.objProp.bar, "baz", "Object expando works"); } catch(e) { is_op(0, 1, "No object expando"); } }