Remove net-telnet dependency to work on Ruby 2.3

lib/devise_cas_authenticatable/memcache_checker.rb

@@ -1,4 +1,5 @@
-require 'net/telnet'
+require 'socket'
+require 'timeout'
 
 module DeviseCasAuthenticatable
   class MemcacheChecker
@@ -17,14 +18,21 @@ def alive?
       memcache_servers.each do |server|
         host, port = server.split(":")
         begin
-          Net::Telnet.new("Host" => host, "Port" => port, "Timeout" => 1)
+          try_connect host, port
+
           return true
-        rescue Errno::ECONNREFUSED
+        rescue Errno::ECONNREFUSED, Timeout::Error
           return false
         end
       end
     end
 
+    def try_connect(host, port)
+      Timeout::timeout(1) do
+        TCPSocket.open(host, port)
+      end
+    end
+
     private
 
     def session_store_class

spec/memcache_checker_spec.rb

@@ -37,7 +37,7 @@
       subject(:alive?) { described_class.new(conf_double).alive? }
 
       before do
-        Net::Telnet.stubs(:new)
+        DeviseCasAuthenticatable::MemcacheChecker.any_instance.stubs(:try_connect)
       end
 
       it { expect(alive?).to eq true }

spec/strategy_spec.rb

@@ -3,8 +3,8 @@
 describe Devise::Strategies::CasAuthenticatable, :type => "acceptance" do
   include RSpec::Rails::RequestExampleGroup
   include Capybara::DSL
-  
-  before do    
+
+  before do
     Devise.cas_base_url = "http://www.example.com/cas_server"
     TestAdapter.reset_valid_users!
 
@@ -13,31 +13,31 @@
       u.username = "joeuser"
     end
   end
-  
+
   after do
     visit destroy_user_session_url
   end
-  
+
   def cas_login_url
     @cas_login_url ||= begin
       uri = URI.parse(Devise.cas_base_url + "/login")
       uri.query = Rack::Utils.build_nested_query(:service => user_service_url)
       uri.to_s
     end
   end
-  
+
   def cas_logout_url
     @cas_logout_url ||= Devise.cas_base_url + "/logout?service"
   end
-  
+
   def sign_into_cas(username, password)
     visit root_url
     current_url.should == cas_login_url
     fill_in "Username", :with => username
     fill_in "Password", :with => password
     click_on "Login"
   end
-  
+
   describe "GET /protected/resource" do
     before { get '/' }
 
@@ -46,28 +46,28 @@ def sign_into_cas(username, password)
       response.should redirect_to(new_user_session_url)
     end
   end
-  
+
   describe "GET /users/sign_in" do
     before { get new_user_session_url }
-    
+
     it 'should redirect to CAS server' do
       response.should be_redirect
       response.should redirect_to(cas_login_url)
     end
   end
-  
+
   it "should sign in with valid user" do
     sign_into_cas "joeuser", "joepassword"
     current_url.should == root_url
   end
-  
+
   it "should fail to sign in with an invalid user" do
     sign_into_cas "invaliduser", "invalidpassword"
     current_url.should_not == root_url
   end
 
   describe "with a deactivated user" do
-    before do 
+    before do
       @user = User.first
       @user.deactivated = true
       @user.save!
@@ -78,13 +78,13 @@ def sign_into_cas(username, password)
       current_url.should == cas_logout_url
     end
   end
-  
+
   it "should register new CAS users if set up to do so" do
     User.count.should == 1
     TestAdapter.register_valid_user("newuser", "newpassword")
     Devise.cas_create_user = true
     sign_into_cas "newuser", "newpassword"
-    
+
     current_url.should == root_url
     User.count.should == 2
     User.find_by_username("newuser").should_not be_nil
@@ -102,7 +102,7 @@ def cas_create_user?
       TestAdapter.register_valid_user("newuser", "newpassword")
       Devise.cas_create_user = false
       sign_into_cas "newuser", "newpassword"
-      
+
       current_url.should == root_url
       User.count.should == 2
       User.find_by_username("newuser").should_not be_nil
@@ -112,13 +112,13 @@ class << User
       end
     end
   end
-  
+
   it "should fail CAS login if user is unregistered and cas_create_user is false" do
     User.count.should == 1
     TestAdapter.register_valid_user("newuser", "newpassword")
     Devise.cas_create_user = false
     sign_into_cas "newuser", "newpassword"
-    
+
     current_url.should_not == root_url
     User.count.should == 1
     User.find_by_username("newuser").should be_nil
@@ -129,12 +129,12 @@ class << User
     click_on "Login"
     current_url.should == root_url
   end
-  
+
   it "should work correctly with Devise trackable" do
     user = User.first
     user.update_attributes!(:last_sign_in_at => 1.day.ago, :last_sign_in_ip => "1.2.3.4", :sign_in_count => 41)
     sign_into_cas "joeuser", "joepassword"
-    
+
     user.reload
     user.last_sign_in_at.should >= 1.hour.ago
     user.sign_in_count.should == 42