let _ = require('lodash');

//Input
var input = [
    { key: '1', val: 'a' },
    { key: '2', val: 'b' },
    { key: '3', val: 'c' }
];

//Desired output
{
    '1': 'a',
    '2': 'b',
    '3': 'c'
}

//Current best solution
_.fromPairs(_.map(input, i => [i.key, i.val]));