Lodash orderBy on nested Arrays of objects

Question

Have an array of objects with some nested properties:

const sports = [{
  name: "Basketball",
  leagues: [{
     createdAt: 1
  }, {
     createdAt: 2
  }]
},{
  name: "Soccer",
  leagues: [{
     createdAt: 3
  }, {
     createdAt: 4
  }]
}]

To get the array of object sorted by name DESC (Z->A) (non nested property) I do:

const sorted = _.orderBy(sports, item => item.name, ['desc']); 

The result is

[{ name: "Soccer", ... },{ name: "Basketball", ... }] 

What I am trying to achieve is to sort this object based on its nested array of objects leagues.createdAt DESC (assuming 1,2,3,4 are the correct timestamps):

[{
  name: "Soccer",
  leagues: [{
     createdAt: 4
  }, {
     createdAt: 3
  }]
},{
  name: "Basketball",
  leagues: [{
     createdAt: 2
  }, {
     createdAt: 1
  }]
}]

Tried to do smth like that:

const sorted = _.orderBy(sports, [(item) => item.leagues[0].createdAt], ["desc"])

but the order is not quite right:

Answer 1

You'll need to map the ordered array, and sort the leagues using _.orderBy(). I'm using _.flow() to create a function that first sorts the entire array, and then maps and sorts the leagues in each object.

const { flow, orderBy, map } = _

const fn = flow(
  arr => orderBy(arr, 'name', 'desc'),
  arr => map(arr,  ({ leagues, ...o }) => ({
    ...o,
    leagues: orderBy(leagues, 'createdAt', 'desc')
  }))
)

const sports = [{"name":"Basketball","leagues":[{"createdAt":1},{"createdAt":2}]},{"name":"Soccer","leagues":[{"createdAt":3},{"createdAt":4}]}]

const result = fn(sports)

console.log(result)

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