Any Javascript or Coffeescript `map` function that transforms object *values*?

Is there no ubiquitous/standard Javascript or Coffeescript function that Transforms the values of an object/map/hash?

jQuery has $.map but it produces Arrays only.
Underscore has _.map but it also produces Arrays only.

To be clear, a function like this one is what I'm looking for. (This example is written in Coffeescript not Javascript.)

# Transforms the values in a map. (Doesn't modify `obj` — returns a new map.)
# Example usage:
#   mapObjVals({ a: 'aa', b: 'bb'}, (key, value) -> value + '_!')
#   --> { a: 'aa_!', b: 'bb_!' }
mapObjVals = (obj, f) ->
  obj2 = {}
  for k, v of obj
    obj2[k] = f k, v
  obj2

Copyright Notice：Content Author:「KajMagnus」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/10974010/any-javascript-or-coffeescript-map-function-that-transforms-object-values