lib/mongo/cluster/sdam_flow.rb in mongo-2.14.0 vs lib/mongo/cluster/sdam_flow.rb in mongo-2.14.1

@@ -176,10 +176,11 @@
         end
       else
         raise ArgumentError, "Unknown topology #{topology.class}"
       end
 
+      verify_invariants
       commit_changes
       disconnect_servers
     end
 
     # Transitions from unknown to single topology type, when a standalone
@@ -361,10 +362,13 @@
           if server = cluster.add(address_str, monitor: false)
             added_servers << server
           end
         end
       end
+
+      verify_invariants
+
       added_servers
     end
 
     # Removes servers from the topology which are not present in the
     # given server description (which is supposed to have come from a
@@ -596,8 +600,18 @@
       server_descriptions = servers_list.map do |server|
         [server.address.to_s, server.description]
       end
 
       @previous_server_descriptions != server_descriptions
+    end
+
+    def verify_invariants
+      if Mongo::Lint.enabled?
+        if cluster.topology.single?
+          if cluster.servers_list.length > 1
+            raise Mongo::Error::LintError, "Trying to create a single topology with multiple servers: #{cluster.servers_list}"
+          end
+        end
+      end
     end
   end
 end