Using a loose array just to specify the object properties

Question

I'm using this array to specify the properties I want to operate on. I didn't use for..in because there's a property that doesn't follow the same pattern.

const data = {};

[
  'teaching_levels',
  'axes',
  'accessibility_resources',
  'contents',
  'resources',
].forEach((name) => {
  data[name] = {
    options: results[name],
    values: req.query[name],
  };
});

// This property is different
data.licenses = results.licenses;

Is it alright to have an array like that?

Answer 1

I would say, yes, definitely. That saves a lot of manual code writing and makes it easier to change in the event you need to change all of them.

The only difference I would probably make is, add your different properties when you create the object, that will not only slightly improve speed, but will also make the code a tiny bit smaller.

const data = {
    licenses: results.licenses
};

[
  'teaching_levels',
  'axes',
  'accessibility_resources',
  'contents',
  'resources',
].forEach(name => data[name] = {
    options: results[name],
    values: req.query[name],
});

Answer 2

I think I would consider something like this:

const data = {
    teaching_levels: null,
    axes: null,
    accessibility_resources: null,
    contents: null,
    resources: null,
    licenses: results.license,
    decorateResults: function () {
        Object.keys(this).forEach( (prop) => { 
            if (this[prop] === null) {
                this[prop] = {
                    options: results[prop],
                    values: req.query[prop]
                };
            }
        });
    }
}
data.decorateResults();

To me this helps make the data model for data more clear. And decouples the operations of data model definition from data population/decoration more clearly. The init() function could, for example, be an external function. If you want even more decoupling, you could simply pass the data structure to the decorator function, rather than having the decorator function living on the object.