json_type.cr

require "json"

def boop(props : JSON::Type)
  puts props
end

boop({ "test" => "test" }) # => {"test" => "test"}

# This has a compile error
#
# instance variable '@props' of Boop must be JSON::Type, not Hash(String, String)
class Boop
  @props : JSON::Type

  def initialize(props : JSON::Type)
    @props = props
  end

  def props
    @props
  end
end

b = Boop.new({ "test" => "test" })
puts b.props