Add specs to prevent dupe migrations_paths regression

[#50099107]

Add specs to verify that the duplicate migrations_paths protection
works.

Author: limhoff-r7

spec/lib/msf/db_manager_spec.rb

@@ -20,6 +20,24 @@
 
 	it_should_behave_like 'Msf::DBManager::ImportMsfXml'
 
+	context '#initialize_metasploit_data_models' do
+		def initialize_metasploit_data_models
+			db_manager.initialize_metasploit_data_models
+		end
+
+		it 'should not add duplicate paths to ActiveRecord::Migrator.migrations_paths' do
+			initialize_metasploit_data_models
+
+			expect {
+				initialize_metasploit_data_models
+			}.to_not change {
+				ActiveRecord::Migrator.migrations_paths.length
+			}
+
+			ActiveRecord::Migrator.migrations_paths.uniq.should == ActiveRecord::Migrator.migrations_paths
+		end
+	end
+
 	context '#purge_all_module_details' do
 		def purge_all_module_details
 			db_manager.purge_all_module_details