1. Software Testing

2. System/Software Testing Error detection and removal determine level of reliability well-planned procedure - Test Cases done by independent quality assurance group (except for unit testing) reveal the presence of errors NOT their absence

3. Software testing is one element of a broader topic that is often referred to as Verification and Validation (V&V) Verification – Have we built the product right? Validation – Have we built the right product? – The software should do what the user really requires Verification vs validation

4. E.g., if we write a program and compile it, we are verifying it. If we then check that it does what we expect, we are validating it

5. Test case design Involves designing the test cases (inputs and outputs) used to test the system The goal of test case design is to create a set of tests that are effective in finding errors

6. OBJECTIVE CRITERIA CONSTRAINT to uncover errors in a complete manner with a minimum of effort and time Test case design Bugs lurk in corners and congregate at boundaries… Boris Beizer

7. Two Types Software testing Black box testing – We choose tests without knowledge of how the program works, i.e., based on requirements only White box testing – We choose test based on our knowledge of how the program works E.g., if the program contains if N ≤ 1000 then.... else.... then testing arbitrary values of N would be black box testing but tests that distinguish N ≤ 1000 and N > 1000 would be white box testing

8. White-box testing … knowing internal working,and exercising different parts test various paths through software; if exhaustive testing is impossible, test high-risk paths

9. Black Box Testing – knowing functions to be performed and testing whether these are performed properly – correct outputs from inputs – test cases designed from user requirements – appropriate at Integration, Systems and Acceptance testing levels

10. Junit Demo