Large Language Models (LLMs) have demonstrated remarkable capabilities in code editing, substantially enhancing software development productivity. However, the inherent complexity of code editing tasks forces existing approaches to rely on LLMs’ autoregressive end-to-end generation, where decoding speed plays a critical role in efficiency. While inference acceleration techniques like speculative decoding are applied to improve the decoding efficiency, these methods fail to account for the unique characteristics of code editing tasks, where changes are typically localized and existing code segments are reused. To address this limitation, we propose EfficientEdit, a novel method that improves LLM-based code editing efficiency through two key mechanisms based on speculative decoding: (1) effective reuse of original code segments while identifying potential edit locations, and (2) efficient generation of edit content via high-quality drafts from edit-oriented draft models and a dynamic verification mechanism that balances quality and acceleration. Experimental results show that EfficientEdit can achieve up to 10.38× and 13.09× speedup compared to standard autoregressive decoding in CanItEdit and CodeIF-Bench, respectively, outperforming state-of-the-art inference acceleration approaches by up to 90.6%. The code and data are available at https://github.com/zhu-zhu-ding/EfficientEdit.

Summary Metamorphic testing (MT) is an effective technique to alleviate the test oracle problem. The principle of MT is to detect failures by checking whether some necessary properties, commonly known as metamorphic relations (MRs), of software under test (SUT) hold among multiple executions of source and follow‐up test cases. Since both the generation of follow‐up test cases and test result verification depend on MRs, the identification of MRs plays a key role in MT, which is an important yet difficult task requiring deep domain knowledge of the SUT. Accordingly, techniques that can direct a tester to identify MRs effectively are desirable. In this paper, we propose MT, a data mutation directed approach to identifying MRs. MT guides a tester to identify MRs by providing a set of data mutation operators and template‐style mapping rules, which not only alleviates the difficulties faced in the process of MR identification but also improves the identification effectiveness. We have further developed a tool to implement the proposed approach and conducted an empirical study to evaluate the MR identification effectiveness of MT and the performance of MRs identified by MT with respect to fault detection capability and statement coverage. The empirical results show that MT is able to identify MRs for numeric programs effectively, and the identified MRs have high fault detection capability and statement coverage. The work presented in this paper advances the field of MT by providing a simple yet practical approach to the MR identification problem.

Web services have been widely used to develop complex distributed software systems in the context of Service Oriented Architecture (SOA). As a standard for describing Web services, the Web Service Description Language (WSDL) provides a universal mechanism to describe the service’s functionalities for the service consumers. However, the current WSDL only provides the description of the interfaces to a Web Service without any restrictions or assumptions on how to properly invoke the service, resulting in divergent understanding of the Web service’s behavior between the service developer and service consumer. A particular challenge is how to make explicit the various behavior assumptions and restrictions of a service (for the user), and make sure that the service implementation conforms to them (for the developer). In this article, we propose a constraint-based model-driven approach to improving the behavior conformance of Web services. In our approach, constraints are introduced in an extended WSDL, called CxWSDL, to formally and explicitly express the implicit restrictions and assumptions on the behavior of a Web service, and then the predefined constraints are used to derive test cases in a model-driven manner to test the service implementation’s conformance to its behavior constraints from the user’s perspective. An empirical study involving four real-life Web services was conducted to evaluate the effectiveness of our approach, and four actual inconsistencies were discovered.

Mutation testing is basically a fault-based software testing technique, which has been proposed to measure the fault detection effectiveness of a test suite using programs with simulated faults (namely mutants). However, mutation testing is time consuming and computationally expensive because of the normal use of a large amount of mutants. Thus, reducing the mutants is of great significance. To address this problem, various mutant reduction techniques have been proposed. Among them, the identification of redundant mutants aims at removing mutants whose test results can be inferred by other mutants. This article proposes a redundant mutant identification technique based on selective symbolic execution called ReMuSSE for weak mutation testing. Redundant mutants could be revealed by identifying those with similar program execution state changes within a program block involving mutated statements. An empirical study was conducted using 13 C programs from different application domains with varying sizes. The empirical results showed that ReMuSSE could identify up to 31.4% redundant mutants and consequentially save up to 35.2% time cost of weak mutation testing. The results demonstrated that ReMuSSE could effectively identify redundant mutants and thus could significantly improve the efficiency of weak mutation testing.

Metamorphic testing is well known for its ability to alleviate the oracle problem in software testing. The main idea ofmetamorphic testing is to test a software system by checking whether each identified metamorphic relation (MR) holds among severalexecutions. In this regard, identifying MRs is an essential task in metamorphic testing. In view of the importance of this identificationtask, METRIC (METamorphic Relation Identification based on Category-choice framework) was developed to help software testersidentify MRs from a given set of complete test frames. However, during MR identification, METRIC primarily focuses on the inputdomain without sufficient attention given to the output domain, thereby hindering the effectiveness of METRIC. Inspired by this problem,we have extended METRIC into METRIC+by incorporating the information derived from the output domain for MR identification. A toolimplementing METRIC+has also been developed. Two rounds of experiments, involving four real-life specifications, have beenconducted to evaluate the effectiveness and efficiency of METRIC+. The results have confirmed that METRIC+is highly effective andefficient in MR identification. Additional experiments have been performed to compare the fault detection capability of the MRsgenerated by METRIC+and those bymMT (another MR identification technique). The comparison results have confirmed that the MRsgenerated by METRIC+are highly effective in fault detection.