Be super clear that a response object is not an Array. Defining this would make implicit splatting work, but it also makes adding responses as arrays work, and “flattening” responses, cascading to the rack body! Not sensible behavior.
# File actionpack/lib/action_dispatch/http/response.rb, line 292 def to_ary ActiveSupport::Deprecation.warn( `ActionDispatch::Response#to_ary` no longer performs implicit conversion to an array. Please use `response.to_a` instead, or a splat like `status, headers, body = *response`..squish) to_a end