Tidy Up Your Source Code! Eliminating Wasteful Statements in Automatically Repaired Source Code.

Automated program repair (APR) is a concept of automatically fixing bugs in source code to free developers from the burden of debugging. One of the issues facing search-based APR is that repaired code contains wasteful or meaningless statements that do not affect external behavior. This paper proposes a concept named source code tidying that eliminates wasteful statements in source code repaired by search-based APR. Our proposed method applies pre-defined tidying rules to repaired code and evaluates the effect of tidying using source code metrics such as lines of code. By repeating this process based on a genetic algorithm, unnatural and full of wasteful source code is gradually brought close to natural with preserving its behavior. Our method will be involved in a process of APR by improving the readability of repaired code.