def convert_keys_to_camel_case(data) # Because some data is not complete equals Hash or Array, # So use is_a? to instead of `when case`` # (e.g. Grape::Entity::Exposure::NestingExposure::OutputBuilder ) if data.is_a? Array data.map do |hash| convert_keys_to_camel_case(hash) end elsif data.is_a? Hash data.transform_keys { |key| key.to_s.camelize(:lower).to_sym } else data end end