Refactoring

Refactoring is a specific technique for restructuring code as a series of small, behavior-preserving transformations.

Refactoring changes a program's source code without changing its external behavior, typically to improve the software's design.

The safety issue—that a refactoring shouldn’t break working code—was recognized as critical to industrial adoption. It also raised other interesting research issues.

Developers won’t use tools that seem unreliable. So, the widespread use of refactoring tools speaks to their apparent reliability. However, they aren’t error-free. They work just well enough to be useful, and they break in relatively unimportant ways.

Refactoring is a key approach for managing technical debt. In the past few years, refactoring techniques and tools have received considerable attention from researchers and tool vendors.

To improve responsiveness, developers often use asynchronous programming. In the post-PC era, asynchronous programming is even more in demand because mobile and wearable devices have limited resources and access the network excessively. One current development task is refactoring long-running, blocking synchronous code (for example, accessing the Web, a cloud, a database, or a file system) into nonblocking asynchronous code.

Although database refactoring has been advocated as an important area of database development, little research has studied its implications. … The experience led to five key lessons learned: refactoring should be automated whenever possible, the database catalog is crucial, refactoring is easier when it's done progressively, refactoring can help optimize an application and streamline its code base, and refactoring related to application development requires a complex skill set and must be applied sensibly.

A refactoring aims to improve a certain quality while preserving others. For example, code refactoring restructures code to make it more maintainable without changing its observable behavior.

Energy efficiency and other sustainability issues are common concerns in the material production industries but rarely addressed in software development efforts. Instead, traditional software development life cycles and methodologies place an emphasis on maintainability and other intrinsic software quality features. One standard practice is to improve maintainability by detecting bad smells in a system's architecture and then applying refactoring transformations to deal with those smells. The refactoring research area is sufficiently mature for most techniques to achieve more maintainable system architectures, but … they can also lead to both decreased sustainability and increased power consumption.

[R]efactoring is limited in what qualities it can help improve. It can also do more harm than good when practiced informally or ad hoc or when it's used as a synonym for any form of change in a system.

Refactoring was originally conceived as a technique for enhancing the design of an existing code base by applying small behavior-preserving transformations to the code. … discuss how to improve the usability of a Web application by applying refactoring on its design structure.

Refactoring tools can improve the speed and accuracy with which developers create and maintain software - but only if they are used. In practice, tools are not used as much as they could be; this seems to be because sometimes they do not align with the refactoring tactic preferred by most programmers, a tactic the authors call 'floss refactoring.' They propose five principles that characterize successful floss-refactoring tools—principles that can help programmers to choose the most appropriate refactoring tools and also help toolsmiths to design tools that fit the programmer's purpose.