I noticed that streaming doesn't work well with filters or middleware. In the following snippet, both stream block 1 and stream block 2 get printed twice. I think this somewhat defeats the purpose of streaming - for instance, if we want to stream something first which doesn't require computation, then stream something requiring computation next. Is there a way for everything in the stream block to only be run once overall? I'd expect middleware to only run once per write.

  after do
    response.body.each do |str|
      # Do things
    end
  end

  get '/stream' do
    stream do |out|
      puts "stream block 1"
      out << "stream block 1"
      puts "stream block 2"
      out << "stream block 2"
    end
  end

stream block 1
stream block 2
stream block 1
stream block 2