lodash-fp list of objects self-join

gistfile1.js

////
//      WARNING: THE FOLLOWING IS ONLY A TEST OF THE EMERGENCY IN-MEMORY ORM
//      NO CLAIMS ARE MADE AS TO THE PRACTICALITY OR WEB-SCALE-NESS OF PERFORMING CLIENT-SIDE JOINS
////

let l = require('lodash-fp')

l.mixin({ id: l.identity })
l.mixin({ prop: l.property })

os = [
    { id: 1, title: 'test1', other_id: [ 3, 2, 5 ] },
    { id: 2, title: 'test2', other_id: [ ] },
    { id: 3, title: 'test3', other_id: [ 2 ] },
    { id: 4, title: 'test4', other_id: [ 3, 2 ] },
    { id: 5, title: 'test5', other_id: [ 1, 2, 4 ] }
]

// copy, updates won't be visible inside the dupes
l.mixin({ set: (o, k, v) => l.assign(o || {}, { [k]: v }) })

// set by ref
l.mixin({ setmut: (o, k, v) => { o[k] = v; return o }})

// join by reference
let joined_os = l.map((o) =>                                    // attach to each o
    l.setmut(o,                                                 
        'others',                                               // on the o.other prop
        l.indexBy(                                              // an index created from
            'id',                                               // the id prop
            l.filter(                                           // from the list of o which
                l.flow(                                         // 
                    l.prop('id'),                               // have an id prop
                    l.partialRight(l.includes, o.other_id)      // included in that o's list of related models
                ),                                              // 
            os)                                                 // 
        )                                                       // 
    )                                                           // 
)(os)                                                           // 

let indexed_os = l.indexBy('id', joined_os)
// => 
// { '1': 
//    { id: 1,
//      title: 'test1',
//      other_id: [ 3, 2, 5 ],
//      others: { '2': [Object], '3': [Object], '5': [Object] } },
//   '2': { id: 2, title: 'test2', other_id: [], others: {} },
//   '3': 
//    { id: 3,
//      title: 'test3',
//      other_id: [ 2 ],
//      others: { '2': [Object] } },
//   '4': 
//    { id: 4,
//      title: 'test4',
//      other_id: [ 3, 2 ],
//      others: { '2': [Object], '3': [Object] } },
//   '5': 
//    { id: 5,
//      title: 'test5',
//      other_id: [ 1, 2, 4 ],
//      others: { '1': [Object], '2': [Object], '4': [Object] } } }

// the following will only work with setmut, set would makes a copy
indexed_os[1]['others'][5]['others'][1] === indexed_os[1]
// => true