askirmas / react-classnaming

function mapping<

  Source extends CssModule,

  Target extends AnyObject,

  Mapping extends ClassNamesMap<OmitIndexed<GetProps<Target>>, Source>

>(

  source: Source,

  _: Target,

  map: Mapping

): {[M in keyof Mapping]: string} {

  // TODO #33 change to for-in https://jsbench.me/prkm3gn4ji

  const keys = $keys(map) as (keyof Mapping)[]

  // TODO = {...keys} + reassign or delete?

  , classnames = {} as {[M in keyof Mapping]: string}

  for (let i = keys.length; i--;) {

    const key = keys[i]

    , val = map[key]

    if (val === undefined)

      continue

    classnames[key] = typeof val === "function"

    ? `${val}`

    : resolver(source,

      //@ts-expect-error #27 TS doesn't understand that ClassNaming is first of all function

      val

    ).join(" ")

  }

  return classnames

}