added stream (for text/event-stream) first draft plugin; allowing bodyless responses (which the parser won't be able to complete) to make an early exit

lib/httpx/channel/http1.rb

@@ -86,16 +86,18 @@ module HTTPX
       log { response.headers.each.map { |f, v| "-> HEADER: #{f}: #{v}" }.join("\n") }
 
       request.response = response
-      # parser can't say if it's parsing GET or HEAD,
-      # call the completeness callback manually
-      dispatch if request.verb == :head ||
-                  request.verb == :connect
+
+      @has_response = true if response.complete?
     end
 
     def on_body(chunk)
       log { "-> DATA: #{chunk.bytesize} bytes..." }
       log(2) { "-> #{chunk.inspect}" }
-      @requests.first.response << chunk
+      response = @requests.first.response
+
+      response << chunk
+
+      dispatch if response.complete?
     end
 
     def on_message_complete

lib/httpx/plugins/stream.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module HTTPX
+  module Plugins
+    module Stream 
+      module InstanceMethods
+        def stream
+          headers("accept" => "text/event-stream",
+                  "cache-control" => "no-cache")
+        end
+      end
+
+      module ResponseMethods
+        def complete?
+          super ||
+            stream? &&
+            @stream_complete
+        end
+
+        def stream?
+          @headers["content-type"].start_with?("text/event-stream")
+        end
+
+        def <<(data)
+          res = super
+          @stream_complete = true if String(data).end_with?("\n\n")
+          res
+        end
+      end
+    end
+    register_plugin :stream, Stream 
+  end
+end

lib/httpx/response.rb

@@ -52,6 +52,10 @@ module HTTPX
       ContentType.parse(@headers["content-type"])
     end
 
+    def complete?
+      bodyless?
+    end
+
     def inspect
       "#<Response:#{object_id} @status=#{@status} @headers=#{@headers}>"
     end