Meteor: How to do a case insensitive collection.findOne()?

Question

I'm implementing a way for users to change their username in a Meteor app I am writing. Before accepting changes, I want to check if the username already exists. Usernames can contain upper and lowercase, but they must be unique names regardless of case. For example, bob and Bob cannot exist together.

The problem is that I can't seem to figure out how to do a collection.findOne() that is case insensitive. For example, say I have a collection called Profiles, I'd like to be able to do something like this:

newName = "bob";

//Assume "Bob" exists as a username in the Profiles collection;

var isAlreadyRegistered = Profiles.findOne({"username": newName});

if (isAlreadyRegistered == null) {
  saveUsername();
};

Answer 1

Your can use regular expression.

var isAlreadyRegistered = Profiles.findOne({"username": /^newName$/i });

Or you can query like this also :

 var isAlreadyRegistered = Profiles.findOne({ "username" : {
                     $regex : new RegExp(newName, "i") } }
               );