Test amplification makes systematic changes to existing, manually written tests to provide tests complementary to an automated test suite. We consider developer-centric test amplification, where the developer explores, judges and edits the amplified tests before adding them to their maintained test suite. However, it is as yet unclear which kind of selection and editing steps developers take before including an amplified test into the test suite. In this paper we conduct an open source contribution study, amplifying tests of open source Java projects from GitHub. We report which deficiencies we observe in the amplified tests while manually filtering and editing them to open 39 pull requests with amplified tests. We present a detailed analysis of the maintainer's feedback regarding proposed changes, requested information, and expressed judgment. Our observations provide a basis for practitioners to take an informed decision on whether to adopt developer-centric test amplification. As several of the edits we observe are based on the developer's understanding of the amplified test, we conjecture that developer-centric test amplification should invest in supporting the developer to understand the amplified tests.

中文翻译：

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动摇，而不是搅拌：开发人员如何喜欢他们的放大测试

测试放大对现有的手动编写的测试进行系统性更改，以提供对自动化测试套件的补充测试。我们考虑以开发人员为中心的测试放大，开发人员在将放大的测试添加到其维护的测试套件之前探索、判断和编辑放大的测试。然而，目前尚不清楚开发人员在将放大测试纳入测试套件之前采取哪种选择和编辑步骤。在本文中，我们进行了一项开源贡献研究，扩大了对 GitHub 开源 Java 项目的测试。我们报告了在放大测试中观察到的缺陷，同时手动过滤和编辑它们以通过放大测试打开 39 个拉取请求。我们对维护者关于提议的更改、请求的信息和表达的判断的反馈进行了详细分析。我们的观察为从业者就是否采用以开发人员为中心的测试放大做出明智的决定提供了基础。由于我们观察到的一些编辑是基于开发人员对放大测试的理解，因此我们推测以开发人员为中心的测试放大应该投资于支持开发人员理解放大测试。