Move connection error handling logic into a new error class

* ConnectionError wraps the creation of several error types for backward compatibility
* For now, ConnectionError is only created when more than 1 error is given to the constructor
* In the future, ConnectionError should be used even in the single error case

lib/net/ldap/connection.rb

@@ -48,14 +48,7 @@ def open_connection(server)
       end
     end
 
-    if errors.size == 1
-      error = errors.first.first
-      raise Net::LDAP::ConnectionRefusedError, error.message if error.kind_of? Errno::ECONNREFUSED
-      raise Net::LDAP::Error, error.message
-    end
-
-    raise Net::LDAP::Error,
-      "Unable to connect to any given server: \n  #{errors.map { |e, h, p| "#{e.class}: #{e.message} (#{h}:#{p})" }.join("\n  ")}"
+    raise Net::LDAP::ConnectionError.new(errors)
   end
 
   module GetbyteForSSLSocket

lib/net/ldap/error.rb

@@ -25,6 +25,25 @@ def warn_deprecation_message
       warn "Deprecation warning: Net::LDAP::ConnectionRefused will be deprecated. Use Errno::ECONNREFUSED instead."
     end
   end
+  class ConnectionError < Error
+    def self.new(errors)
+      error = errors.first.first
+      if errors.size == 1
+        if error.kind_of? Errno::ECONNREFUSED
+          return Net::LDAP::ConnectionRefusedError.new(error.message)
+        end
+
+        return Net::LDAP::Error.new(error.message)
+      end
+
+      super
+    end
+
+    def initialize(errors)
+      message = "Unable to connect to any given server: \n  #{errors.map { |e, h, p| "#{e.class}: #{e.message} (#{h}:#{p})" }.join("\n  ")}"
+      super(message)
+    end
+  end
   class NoOpenSSLError < Error; end
   class NoStartTLSResultError < Error; end
   class NoSearchBaseError < Error; end

test/test_ldap_connection.rb

@@ -42,7 +42,7 @@ def test_list_of_hosts_with_all_hosts_failure
     flexmock(TCPSocket).should_receive(:new).ordered.with(*hosts[1]).once.and_raise(SocketError)
     flexmock(TCPSocket).should_receive(:new).ordered.with(*hosts[2]).once.and_raise(SocketError)
     flexmock(TCPSocket).should_receive(:new).ordered.never
-    assert_raise Net::LDAP::Error do
+    assert_raise Net::LDAP::ConnectionError do
       Net::LDAP::Connection.new(:hosts => hosts)
     end
   end