send connection preface on receive (#142)

* send connection on preface on receive, in case the client hasn't sent his own settings (currently this is being done only if the first message is from the client)
* do not set stream id in the test, as streams already have a proper stream id, and it will interfere with inferring if it's a connection frame (like, when you set a data frame with 0 as id)
* added test for the client initialization

lib/http/2/client.rb

@@ -38,6 +38,11 @@ def send(frame)
       super(frame)
     end
 
+    def receive(frame)
+      send_connection_preface
+      super(frame)
+    end
+
     # sends the preface and initializes the first stream in half-closed state
     def upgrade
       fail ProtocolError unless @stream_id == 1

lib/http/2/connection.rb

@@ -360,7 +360,10 @@ def receive(data)
       raise if e.is_a?(Error::Error)
       connection_error(e: e)
     end
-    alias << receive
+
+    def <<(*args)
+      receive(*args)
+    end
 
     private
 

spec/client_spec.rb

@@ -32,6 +32,18 @@
       expect(frame[:type]).to eq :settings
       expect(frame[:payload]).to include([:settings_max_concurrent_streams, 200])
     end
+
+    it 'should initialize client when receiving server settings before sending ack' do
+      frames = []
+      @client.on(:frame) { |bytes| frames << bytes }
+      @client << f.generate(SETTINGS.dup)
+
+      expect(frames[0]).to eq CONNECTION_PREFACE_MAGIC
+      expect(f.parse(frames[1])[:type]).to eq :settings
+      ack_frame = f.parse(frames[2])
+      expect(ack_frame[:type]).to eq :settings
+      expect(ack_frame[:flags]).to include(:ack)
+    end
   end
 
   context 'upgrade' do

spec/connection_spec.rb

@@ -10,7 +10,6 @@
   context 'initialization and settings' do
     (FRAME_TYPES - [SETTINGS]).each do |frame|
       it "should raise error if first frame is #{frame[:type]}" do
-        frame = set_stream_id(f.generate(frame.deep_dup), 0x0)
         expect { @conn << frame }.to raise_error(ProtocolError)
         expect(@conn).to be_closed
       end