class ReeMapper::Integer

def cast(value)
  if value.is_a?(Integer)
    value
  elsif value.is_a?(String)
    coerced_value = Integer(value, exception: false)
    if coerced_value.nil?
      raise ReeMapper::CoercionError.new("is invalid integer, got `#{truncate(value.inspect)}`")
    end
    coerced_value
  else
    raise ReeMapper::TypeError.new("should be an integer, got `#{truncate(value.inspect)}`")
  end
end