Secret mouse!

secret-mouse.js

let animal = {
  animalType: 'animal',
 
  describe () {
    return `An ${this.animalType} with ${this.furColor} fur, 
      ${this.legs} legs, and a ${this.tail} tail.`;
  }
};
 
let mouseFactory = function mouseFactory () {
  let secret = 'secret agent';

  return Object.assign(Object.create(animal), {
    animalType: 'mouse',
    furColor: 'brown',
    legs: 4,
    tail: 'long, skinny',
    profession () {
      return secret;
    }
  });
};
 
let james = mouseFactory();

i'm curious about line 10:
let mouseFactory = function mouseFactory () {

Are there any benefits in naming the anonymous function? What would be the difference in writing it like this?
let mouseFactory = function () {

And to take it further with ES6 syntax...
let mouseFactory = () => {

Just curious if there are any benefits that I'm not aware of.

It's not anonymous if it has a name. The primary benefit is that the name will appear in debugging callstacks.

The proper terminology for this is "named function expression".

cool, thanks, makes sense. i've seen this in the past and have always wondered.

There is one more thing I would like to clarify. Why you used named function expression instead of function declaration in this particular case? Is it just your preferred style or there is something more to it?

Only difference between two approches I could recognise is that named function expression won't be hoisted so you can't use it before line 10.