Systematic Analysis of Defect-Specific Code Abstraction for Neural Program Repair

Automated program repair(APR) is in the spotlight in academia and the field to reduce the time and cost of maintenance for developers. Recently, APR has continued to study based on deep-learning models to understand and learn how to fix software bugs. Text-to-Text Transfer Transformer(T5), which scored state-of-the-art in natural language processing benchmarks, also showed promising results on program repair in recent studies. In deep-learning-based program repair studies, studies commonly propose code abstraction techniques to avoid vocabulary problems and learn fine code transformation to generate bug-fixing patches. However, there is not enough systematic analysis of code abstraction according to each bug type in deep-learning-based program repair. Therefore, We leverage TFix, T5-based program repair, to evaluate how code abstraction techniques affect neural program repair. Our experimental results showed that defect-specific code abstraction achives a higher average BLEU score than the existing code abstraction technique in both T5 and multilingual-T5(mT5) model-based TFix results. Also, mT5 model-based TFix, which is applied defect-specific code abstraction, gets a higher BLEU score in 37 error types of 52 ESLint error types than TFix.