Refactoring for TTCN-3 Test Suites

Experience with the development and maintenance of test suites has shown that the Testing and Test Control Notation (TTCN-3) provides very good concepts for adequate test specification. However, experience has also demonstrated that during either the migration of legacy test suites to TTCN-3, or the development of large TTCN-3 test specifications, users have found it is difficult to construct TTCN-3 tests that are concise with respect to readability, usability, and maintainability. To address these issues, this paper investigates refactoring for TTCN-3; systematically restructuring a test suite without changing its behaviour. Complementary metrics are suggested to assess the readability and maintainability of TTCN-3 test suites. For automation, a tool called TRex has been developed that supports refactoring and metrics for TTCN-3.