Java Script/jQuery – Simple if-statement not working with pre-defined variable

Sorry, I'm kind of new to this.

Is there a specific reason, why the if-statement in this snippet is not working? If yes, could somebody point me in the right direction?

var app = (function(){
   selector = {
       app: ".js-app",
       app__home: ".js-app__home"
   }

   foo();

   foo = function () {
     console.log(selector.app__home);
     if ($(selector.app).hasClass(selector.app__home)) {
        console.log("is home page")
     }
   }       
})();

$(document).on("ready", function() {
   app();
});

The first console.log()-output (the one outside the if-statement) works correctly though. Thanks!