Hash deep set in ruby

hash_deep_set.rb

class Query
  attr_reader :query

  def initialize
    @query = { b: 2 }
  end

  def deep_set(*keys, val)
    key = keys.pop
    keys.inject(query) { |hsh, k| hsh.key?(k) ? hsh[k] : hsh[k] = {}; hsh[k] }[key] = val
  end
end

q = Query.new
keys = [:a, :b]
q.deep_set(*keys, 1)
p q.query.inspect # => "{:b=>2, :a=>{:b=>1}}"
p keys # => [:a, :b]