Add test for HTTP#protocol_for.

Author: ioquatix

test/async/http/protocol/http.rb

@@ -8,6 +8,31 @@
 require "async/http/a_protocol"
 
 describe Async::HTTP::Protocol::HTTP do
+	with "#protocol_for" do
+		let(:protocol) {subject::DEFAULT}
+		let(:buffer) {StringIO.new}
+		
+		it "it can detect http/1.1" do
+			buffer.write("GET / HTTP/1.1\r\nHost: localhost\r\n\r\n")
+			buffer.rewind
+			
+			stream = IO::Stream(buffer)
+			
+			expect(protocol.protocol_for(stream)).to be == Async::HTTP::Protocol::HTTP1
+		end
+		
+		it "it can detect http/2" do
+			# This special preface is used to indicate that the client would like to use HTTP/2.
+			# https://www.rfc-editor.org/rfc/rfc7540.html#section-3.5
+			buffer.write("PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n")
+			buffer.rewind
+			
+			stream = IO::Stream(buffer)
+			
+			expect(protocol.protocol_for(stream)).to be == Async::HTTP::Protocol::HTTP2
+		end
+	end
+	
 	with "server" do
 		include Sus::Fixtures::Async::HTTP::ServerContext
 		let(:protocol) {subject}