Regression test selection (RTS) approaches reduce the number of regression tests. Current RTS approaches are typically monoglot, i.e., their implementations target a specific language. However, many subjects under test (SUT) are polyglot, i.e., they use multiple languages. Running multiple monoglot RTS approaches separately on a polyglot SUT is unsafe because tests that involve inter-language dependencies can be missed. Moreover, a new language may require completely reimplementing an RTS approach, especially if the original implementation relies on language and runtime features that are not available in the new language. We propose a new static approach called BabelRTS, which is multilingual (supports multiple languages out of the box), polyglot (analyzes SUTs written in multiple languages), and extensible (allows adding support for new languages). A key contribution is the idea of encapsulating the language-specific aspects of RTS by using patterns and actions. A pattern specifies programming language constructs used in each file that indicate dependencies to other files written in the same or a different language. An action specifies how to identify these files in the codebase. Patterns and actions can be customized to support new languages without modifying the test selection algorithm. BabelRTS is not tied to a specific language run-time system or paradigm. BabelRTS currently supports 12 languages and 5 language combinations. We evaluated BabelRTS on 142 open-source monoglot and polyglot SUTs, analyzing a total of more than two billion LOC. The performance of BabelRTS was similar to the state-of-the-art monoglot approaches on monoglot SUTs. On polyglot SUTs, BabelRTS was safer in polyglot mode and selected more tests for 60% of the commits than in monoglot mode, which missed inter-language dependencies.

Abstract Regression test selection (RTS) approaches reduce the cost of regression testing of evolving software systems. Existing RTS approaches based on UML models use behavioral diagrams or a combination of structural and behavioral diagrams. However, in practice, behavioral diagrams are incomplete or not used. In previous work, we proposed a fuzzy logic based RTS approach called FLiRTS that uses UML sequence and activity diagrams. In this work, we introduce FLiRTS 2, which drops the need for behavioral diagrams and relies on system models that only use UML class diagrams, which are the most widely used UML diagrams in practice. FLiRTS 2 addresses the unavailability of behavioral diagrams by classifying test cases using fuzzy logic after analyzing the information commonly provided in class diagrams. We evaluated FLiRTS 2 on UML class diagrams extracted from 3331 revisions of 13 open-source software systems, and compared the results with those of code-based dynamic (Ekstazi) and static (STARTS) RTS approaches. The average test suite reduction using FLiRTS 2 was 82.06%. The average safety violations of FLiRTS 2 with respect to Ekstazi and STARTS were 18.88% and 16.53%, respectively. FLiRTS 2 selected on average about 82% of the test cases that were selected by Ekstazi and STARTS. The average precision violations of FLiRTS 2 with respect to Ekstazi and STARTS were 13.27% and 9.01%, respectively. The average mutation score of the full test suites was 18.90%; the standard deviation of the reduced test suites from the average deviation of the mutation score for each subject was 1.78% for FLiRTS 2, 1.11% for Ekstazi, and 1.43% for STARTS. Our experiment demonstrated that the performance of FLiRTS 2 is close to the state-of-art tools for code-based RTS but requires less information and performs the selection in less time.

We introduce an algorithm that computes and counts the duals of finite Gödel-Dummett algebras of k ≥ 1 elements.The computational cost of our algorithm depends on the factorization of k, nevertheless a Python implementation is sufficiently fast to compute the results for very large values of k.