TENDER-BLOCK: Testing, Debugging, and Repairing Blocks-Based Programs

可视化的、基于块的编程环境(如Scratch)越来越多地用于向学习者介绍编程概念，并使非专业软件工程师的领域专家能够创建程序。尽管这种方法成功地降低了编写计算机程序的门槛，但基于文本的专业编程语言的高级工具包通常不适用于可视化编程语言。在某种程度上，这是因为人工分析和解决问题是一个重要的学习方面，具有很高的教育价值。然而，这很难成为完全没有工具支持的理由，因为在许多情况下，缺乏这种支持会导致负面影响：从学习者的角度来看，人们担心在缺乏任何质量感的情况下获得的编程和软件工程技能，就像当前常见的学习场景中的情况一样，解决编程挑战的困难可能会阻碍在其他领域实现预期的学习结果(例如，当编程被用作传达数学概念的工具时)。从教师的角度来看，监控学习进度，支持学习者，从用户的角度来看，寻找和修复错误，确定程序何时完成，是否按预期工作，以及实现的质量如何，都取决于直觉和手动探索。这对新手和学习程序员来说尤其令人沮丧，特别是那些试图在课程活动之外从事编程的人，导致编程项目被放弃，以及用户对编程失去兴趣。该项目的总体目标是使基本的软件工程技术能够支持基于块的编程语言的测试、调试和修复。为了实现这一目标，该项目将：(1)使基本的静态程序分析适用于基于块的程序，(2)开发用于测试基于块的程序的概念和框架，(3)设计自动测试基于块的程序的技术，以及(4)开发手动、交互和自动调试和修复基于块的程序的技术。这些技术将在Scratch 3.0编程环境中实施和评估，并将使进一步的研究能够分析基于块的程序以及将这些分析集成到教育环境中。

Visual, blocks-based programming environments like Scratch are increasingly used to introduce learners to programming concepts, and to enable domain experts, who are not professional software engineers, to create programs. Although this approach successfully lowers entry barriers into writing computer programs, the advanced toolkits of professional, text-based programming languages are usually not available on visual programming languages. To some extent, the reason for this is that manually analysing and solving problems is an important learning aspect and of high educational value. Albeit, this hardly justifies the complete absence of tool support, since there are many scenarios where the absence of such support leads to negative implications:From a learner's perspective, there are concerns about the programming and software engineering skills achieved in absence of any sense of quality, as is the case in the currently common learning scenario, and difficulties in solving programming challenges can get in the way achieving the intended learning outcomes in other domains (e.g., when programming is used as a tool to convey mathematical concepts).From a teacher's perspective, monitoring learning progress, supporting learners, and assessing and grading learning outcomes is challenging and tedious.From a user perspective, finding and fixing bugs, determining when a program is finished, whether it is working as expected, and what the quality of the implementation is, is down to intuition and manual exploration. This is particularly frustrating for novice and learning programmers, especially those attempting to engage with programming outside of a curricular activity, resulting in abandoned programming projects, as well as users losing interest in programming.The overall aim of this project is to enable essential software engineering techniques supporting testing, debugging, and fixing for blocks-based programming languages. To achieve this goal, the project will: (1) adapt essential static program analyses to blocks-based programs,(2) develop a concept and framework for testing blocks-based programs,(3) devise techniques to automatically test blocks-based programs, and (4) develop techniques to manually, interactively, and automatically debug and repair blocks-based programs.These techniques will be implemented and evaluated in the context of the Scratch 3.0 programming environment, and will enable further research on analysing blocks-based programs as well as integrating these analyses into an educational context.