Group array of object nesting some of the keys with specific names

Question

I have this array of objects, that I need to modify to make it easier the rendering.

const items = [
  {
    tab: \'Results\',
    section: \'2017\',
    ti         


        

Answer 1

This can be done with a clever combinartion of _.map and _.groupBy.

const items = [
  {
    tab: 'Results',
    section: '2017',
    title: 'Full year Results',
    description: 'Something here',
  },
    {
    tab: 'Results',
    section: '2017',
    title: 'Half year Results',
    description: 'Something here',
  },
    {
    tab: 'Reports',
    section: 'Marketing',
    title: 'First Report',
    description: 'Something here',
  }
];

function groupAndMap(items, itemKey, childKey, predic){
    return _.map(_.groupBy(items,itemKey), (obj,key) => ({
        [itemKey]: key,
        [childKey]: (predic && predic(obj)) || obj
    }));
}

var result = groupAndMap(items,"tab","sections", 
                   arr => groupAndMap(arr,"section", "items"));


console.log(result);