Add method to remove falsy values from objects

[raingerber]

Problem description:

I've noticed a pattern of wanting to remove falsy values from objects, but there's no elegant way of doing that:

const reducer = [
  input => {
    // get the "a" and "b" properties, but only if they're truthy
    // this works, but it's awkward and boilerplate-ish
    const result = {}
    if (obj.a) result.a = a
    if (obj.b) result.b = b
    return obj
  }
]

Suggested solution:

I don't know, but these are a few ideas:

Proposal # 1

const reducer = {
  '?a': '$a', // only include this if "$a" is truthy
  b: '$b'
}

This works, but we removed the special treatment for keys beginning with '$', so this feels like going backward.

Proposal # 2

// not the best name...
const { removeFalsy } = DataPoint.helpers

removeFalsy({
  a: '$a',
  b: '$b'
})

This would remove every falsy value, but we might want to keep some of them.

Proposal # 3

// another not-so-great name...
const { truthy } = DataPoint.helpers

{
  a: truthy('$a'),
  b: '$b'
}

It could work? Feels weird though...

Summary

It would be nice if we don't add a new reducer helper, especially because it would only be useful for object reducers. Not sure if there's a good solution though!