Treating Software Quality as a First-Class Entity

Quality is a crucial property of any software system and consists of many aspects. On the one hand, quality measures how well a piece of software satisfies its functional requirements. On the other hand, it captures how easy it is to understand, test and modify a software system. While functional requirements are provided by the product owner, maintainability of software is often underestimated. Currently software quality is either assessed by experts, or presented as a list of rule violations reported by some kind of static analyzer. Both these approaches are working with a sense of quality outside of the software itself. We envision quality as a first-class entity of a software system, a concept that similarly to the functionality is persistent within the software itself. We believe that each entity or a group of software entities should be able to tell about its quality, reasons of bad smells and ways to resolve them. This concept will allow to build quality aware tools for each step of the software development lifecycle. On our way to the concept of quality as a first class entity, we have created a code review approach where software quality is the main concern. A reviewer makes decisions and takes actions based on the quality of the reviewed system. We plan to continue our research by integrating advanced quality rules into our tools and devising new approaches to represent quality and integrate it into everyday workflow. We started to develop a layer on top of a software model responsible for the quality feedback and allowing to develop quality-aware IDE plugins.