tailieunhanh - The art of software testing second edition - phần 4

Bạn có thể muốn xem xét những trường hợp thử nghiệm so sánh với một tập hợp các trường hợp kiểm tra nguồn gốc một cách quảng cáo đặc biệt. Mặc dù phân vùng là bao la cấp trên tương đương với một lựa chọn ngẫu nhiên các trường hợp thử nghiệm, nó vẫn có thiếu sót | Simpo PDF1 M ergeandaSpliteUnregistered Version - http 25 DIMENSION D - 65535 1 26 DIMENSION D 65536 31 DIMENSION D 4 3 37 DIMENSION D A 2 4 38 D . 4 Hence the equivalence classes have been covered by 18 test cases. You may want to consider how these test cases would compare to a set of test cases derived in an ad hoc manner. Although equivalence partitioning is vastly superior to a random selection of test cases it still has deficiencies. It overlooks certain types of high-yield test cases for example. The next two methodologies boundary-value analysis and cause-effect graphing cover many of these deficiencies. Boundary-Value Analysis Experience shows that test cases that explore boundary conditions have a higher payoff than test cases that do not. Boundary conditions are those situations directly on above and beneath the edges of input equivalence classes and output equivalence classes. Boundary-value analysis differs from equivalence partitioning in two respects 1. Rather than selecting any element in an equivalence class as being representative boundary-value analysis requires that one or more elements be selected such that each edge of the equivalence class is the subject of a test. 2. Rather than just focusing attention on the input conditions input space test cases are also derived by considering the result space output equivalence classes . It is difficult to present a cookbook for boundary-value analysis since it requires a degree of creativity and a certain amount of specialization toward the problem at hand. Hence like many other aspects of testing it is more a state of mind than anything else. However a few general guidelines are as follows 1. If an input condition specifies a range of values write test cases for the ends of the range and invalid-input test cases for situations just beyond the ends. For instance if the valid domain of an input value is write test cases for the situations and . 2. If an input .