Removing all empty elements from a hash / YAML?

Question

How would I go about removing all empty elements (empty list items) from a nested Hash or YAML file?

Answer 1

The recursive version of https://stackoverflow.com/a/14773555/1519240 works, but not with HashWithIndifferentAccess or other classes that are kind of Hash..

Here is the version I am using:

def recursive_compact
  inject({}) do |new_hash, (k,v)|
    if !v.nil?
      new_hash[k] = v.kind_of?(Hash) ? v.recursive_compact : v
    end
    new_hash
  end
end

kind_of?(Hash) will accept more classes that are like a Hash.

You can also replace inject({}) by inject(HashWithIndifferentAccess.new) if you want to access the new hash using both symbol and string.