What is the name of this pattern? Is it even optimal?

Sorry the title couldn't be more specific. I do this in Javascript sometimes to 'attach' a variable to an anonymous function but I'm not sure of the vocabulary so I don't know how to study more about it or see if what I'm doing is optimal.

I'm using MEAN stack with Mongoose to create a getter function on every member of the schemas.

testPlugin.plugin = function(schema, options){
    schema.set('toObject', { getters: true });
    schema.set('toJSON', { getters: true });

    // Simple counter
    let i = 0;

    schema.eachPath((path, type) => {

        /* Add a *different* getter to each member with a different value of `i` */
        type.getters.push(((i, type)=>{
                return function(value){
                console.log(i + ": " + path + ": " + type);
                return value;
            }
        })(i, type));

        i++;
    });
}

Basically if I were to just pass 'i' to the function and there were 5 members, all of the functions would trace something like

'5: path.path: String'
'5: path.path: Integer'
'5: path.path: ObjectID'
'5: path.path: String'

Instead of having the value 'stored' as it were in the function which, when executed on a schema would trace out something like

'1: patha: String'
'2: pathint: Integer'
'3: _id: ObjectID'
'4: path.path: String'

So instead I'm returning a new, separate function each time by returning a function from an auto-executed parent function... is this correct or am I going overkill here?

Again, just really looking for the name of this pattern or what pattern I should be using. I saw something similar to this but I forgot.