Can't use an array variable with the mongoose validator 'enum'

The following enum validation is ignored in the Node.js library mongoose.js:

myArray = ["one", "two", "three"];

const numbers = new mongoose.Schema({
    range: { type: String, enum: myArray }
});

However, using the array explicitly with enum works, e.g:

range: { type: String, enum: ["one", "two", "three"] }

Is there any way to make enum work with an array reference?

I am currently using: Node.js@v9.8.0 mongoose@5.0.9 MongoDB@2.6.10

Thank you in anticipation.