Add selectEntries as a mapEntries that can also filter out entries

[aleclarson]

Copied from sodiray/radash#364

Basically, it does the following but in a more performant manner:

import { select } from 'radashi'

export function selectEntries(object, map, filter) {
  return Object.fromEntries(
    select(
      Object.entries(object),
      map,
      filter,
    ),
  )
}

selectEntries(
  object,
  ([key, value]) => [key.toUpperCase(), `${value}`],
  ([key]) => key !== 'power',
)

PR welcome

[Minhir]

For me, select looks like Abstraction over sugar. But select is already here, so I don't propose to remove it. Just trying to be careful with introducing new API. What do you think about select type extension? It can also accept an object as first argument.

select(
  object,
  ([key, value]) => [key.toUpperCase(), `${value}`],
  ([key]) => key !== 'power',
)

[aleclarson]

Yeah I think you're right that selectEntries isn't gonna cut it. It's better for readability to write out the loop manually:

const newObj = {}
for (const [key, value] of Object.entries(newObj)) {
  if (condition(key, value)) {
    newObj[key] = value
  }
}