allow RST_STREAM to be received when a stream has been recently closed

as per spec. fixed other tests wrongly using closed streams.

.rubocop.yml

@@ -21,6 +21,9 @@ Layout/HeredocIndentation:
 Metrics/BlockLength:
   Enabled: false
 
+Metrics/PerceivedComplexity:
+  Enabled: false
+
 Lint/EmptyWhen:
   Enabled: false
 

lib/http/2/connection.rb

@@ -391,6 +391,13 @@ def receive(data)
                 stream = @streams_recently_closed[frame[:stream]]
                 connection_error(:protocol_error, msg: "sent window update on idle stream") unless stream
                 process_window_update(frame: frame, encode: true)
+              # Endpoints MUST ignore
+              # WINDOW_UPDATE or RST_STREAM frames received in this state (closed), though
+              # endpoints MAY choose to treat frames that arrive a significant
+              # time after sending END_STREAM as a connection error.
+              when :rst_stream
+                stream = @streams_recently_closed[frame[:stream]]
+                connection_error(:protocol_error, msg: "sent window update on idle stream") unless stream
               else
                 # An endpoint that receives an unexpected stream identifier
                 # MUST respond with a connection error of type PROTOCOL_ERROR.

spec/client_spec.rb

@@ -205,7 +205,6 @@
       it "should emit :altsvc" do
         s = client.new_stream
         s.send headers_frame
-        s.close
 
         frame = nil
         s.on(:altsvc) { |f| frame = f }
@@ -217,7 +216,6 @@
       it "should not emit :alt_svc when the frame when contains a origin" do
         s = client.new_stream
         s.send headers_frame
-        s.close
 
         frame = nil
         s.on(:altsvc) { |f| frame = f }
@@ -270,7 +268,6 @@
       it "should be ignored" do
         s = client.new_stream
         s.send headers_frame
-        s.close
 
         expect do
           client << set_stream_id(f.generate(orig_frame), s.id)

spec/server_spec.rb

@@ -118,9 +118,21 @@
       stream.send data_frame
       stream.close
 
+      # WINDOW_UPDATE or RST_STREAM frames can be received in this state
+      # for a short period
       expect do
         srv << f.generate(rst_stream_frame.merge(stream: stream.id))
       end.to_not raise_error
+
+      expect do
+        srv << f.generate(window_update_frame.merge(stream: stream.id))
+      end.to_not raise_error
+
+      # PRIORITY frames can be sent on closed streams to prioritize
+      # streams that are dependent on the closed stream.
+      expect do
+        srv << f.generate(priority_frame.merge(stream: stream.id))
+      end.to_not raise_error
     end
   end