test: Define some helpers as test-utils
test: Load required modules
test: Fix global leak
test: No need to load Connection module from the Socket.IO API test
test: Fix typo
test: Test regsteration of REST APIs without mocked connection
test: Test express-adaptor without mocked connection
test: Remove obsolete codes
test: Utilize assertion for backend received messages
test: Utlize operations to send messages from the backend