Implement RFC 8305, the "Happy Eyeballs".

lib/http/network/tcp_socket.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require "socket"
+
+module HTTP
+  module Network
+    class TCPSocket
+      class << self
+        def new(...)
+          ::Socket.tcp(...)
+        end
+
+        def open(...)
+          new(...)
+        end
+      end
+    end
+  end
+end

lib/http/options.rb

@@ -2,12 +2,12 @@
 
 require "http/headers"
 require "openssl"
-require "socket"
+require "http/network/tcp_socket"
 require "http/uri"
 
 module HTTP
   class Options # rubocop:disable Metrics/ClassLength
-    @default_socket_class     = TCPSocket
+    @default_socket_class     = Network::TCPSocket
     @default_ssl_socket_class = OpenSSL::SSL::SSLSocket
     @default_timeout_class    = HTTP::Timeout::Null
     @available_features       = {}

spec/lib/http/client_spec.rb

@@ -385,7 +385,7 @@ def on_error(request, error)
       end
 
       it "is given a chance to handle a connection timeout error" do
-        allow(TCPSocket).to receive(:open) { sleep 1 }
+        allow(HTTP::Network::TCPSocket).to receive(:open) { sleep 1 }
         sleep_url = "#{dummy.endpoint}/sleep"
         feature_instance = feature_class.new
 
@@ -570,7 +570,7 @@ def wrap_response(res)
         allow(socket_spy).to receive(:readpartial) { chunks.shift || :eof }
         allow(socket_spy).to receive(:write) { chunks[0].length }
 
-        allow(TCPSocket).to receive(:open) { socket_spy }
+        allow(HTTP::Network::TCPSocket).to receive(:open) { socket_spy }
       end
 
       it "properly reads body" do

spec/support/http_handling_shared.rb

@@ -73,7 +73,7 @@
     let(:response) { client.get(server.endpoint).body.to_s }
 
     it "errors if connecting takes too long" do
-      expect(TCPSocket).to receive(:open) do
+      expect(HTTP::Network::TCPSocket).to receive(:open) do
         sleep 1.25
       end