Test Case Designing培训课件.ppt

Looks for exceptional conditions, extremes, boundaries, and abnormalities. Requires experience, creativity of the Test Engineer Need: Extreme cases Extracted cases involved extracting samples of real data for the testing process. Randomized cases involved using tools to generate potential data for the testing process. Extracted and Randomized cases 1. Equivalence Partitioning 2. Boundary Value Analysis 3. Error Guessing Test case Design methods Equivalence class is a subset of data that is representative of a larger class Divide input domain into equivalence classes Attempt to cover classes of errors One test case per equivalence class, to reduce total number of test cases needed Input Domain Equivalence partitioning A program which accepts credit limits with a given range Say, $10,000 – $15,000 This would have three equivalence classes:- 1. Less than $10,000 (Invalid) 2. Between $10,000 and $15,000 (Valid) 3. Greater than $15,000 (Invalid) Example Less than 10,000 Between 10 and 15 More than 15,000 9800 12500 18000 Equivalence Partitions Complements equivalence partitioning , selects the test cases at the “edge” of equivalence classes. In practice, more errors found at boundaries of equivalence classes than within the classes Divide input domain into equivalence classes A technique that consists of developing test cases and data that focus on the input and output boundaries of a given function Boundary Value Analysis In the same credit limit example: the boundary analysis would test 1. low boundary plus or minus one ($ 9,999 and $10,001) 2. On the boundary ($10,000 and $15000) 3. Upper boundary plus or minus one ($14999 and $15001) Example ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, Input data and output results often fall into different classes where all members of a class are related Each of these classes is an equivalence partition where the program behaves in an equivalent way for each class member Test cases should be chose