Test blueprint: an effective visual support for test coverage

Test coverage is about assessing the relevance of unit tests against the tested application. It is widely acknowledged that a software with a "good" test coverage is more robust against unanticipated execution, thus lowering the maintenance cost. However, insuring a coverage of a good quality is challenging, especially since most of the available test coverage tools do not discriminate software components that require a "strong" coverage from the components that require less attention from the unit tests. HAPAO is an innovative test covepage tool, implemented in the Pharo Smalltalk programming language. It employs an effective and intuitive graphical representation to visually assess the quality of the coverage. A combination of appropriate metrics and relations visually shapes methods and classes, which indicates to the programmer whether more effort on testing is required. This paper presents the essence of HAPAO using a real world case study.