CIS 2750 – Testing Exam Questions and Answers

CIS 2750 – Testing Exam Questions and Answers True or False: Testing is the same as debugging. - answer- False. Testing is the systematic attempt to break a program, while debugging is the process of fixing and removing errors. True or False: Testing can take upwards of 40 percent of total development time. - answer- True. It is not unusual for developers to spend 40% of the total project time on testing. • For life-critical software (e.g. flight control, reactor monitoring), testing can cost 3 to 5 times as much as all other activities combined. True or False: Testing can prove the absence of errors. - answer- False, testing cannot show (or prove!) the absence of defects -- it can only show that software defects are present. Testing - answer- The process of executing a program with the intent of finding an error. A ____ test case is one that has a high probability of finding an as yet undiscovered error. - answer- Good A __________ test is one that uncovers an as yet undiscovered error. - answer- Successful Testing should systematically uncover _________ _______ of errors in a minimum amount of time and with a minimum amount of effort. - answer- Different Classes • A secondary benefit of testing is that it demonstrates that the software appears to be working as stated in the specification. • The data collected through testing can also provide an indication of the software's reliability and quality. Typographical errors are ______. - answer- Random Logic errors and incorrect assumptions are _________ ____________ to the probability that a program path will be executed. - answer- Inversely Proportional • General processing tends to be well understood, while special case processing tends to be prone to errors. • However, we often believe that a logical path is not likely to be executed when in fact, it may be executed on a regular basis. • Our unconscious assumptions about control flow and data lead to design errors that can only be detected by testing. Black Box Testing - answer- • Consider only public interface of module or entire program • Apply inputs → examine outputs → compare to spec • Ideally done by independent testing group - NOT the original programmer White Box Testing - answer- Involves looking at module's source code, then targeting tests to exercise particular statements Proper White Box Testing will: - guarantee that all ___________ _____ within a module have been exercised at least once, - exercise all _______ _________ on their true and false sides, - execute all _____ at their boundaries and within their operational bounds, and - exercise internal ____ __________ to ensure their validity. - answer- Independent Paths, Logical Decisions, Loops, Data Structures 3 Steps to Testing Nirvana - answer- Step 1: Consider all possible problems as you implement a solution. Consider array boundaries, loop boundaries, ranges for variable values, etc. - Consider all the situations a block of code could have and design tests for them. Step 2: Test systematically, starting with easy tests and working up to more elaborate ones. Step 3: Within a module, test incrementally as you code. TLDR: Know your code boundaries, test systematically (simple - complex), test often. GIGO - answer- ("garbage in, garbage out") means that if your input is incorrect, your output is worthless. - In some cases its unavoidable (various data analysis methods) - Include "garbage in" in your test cases, to make sure defensive code is working as desired cmp - answer- Compare files for identity - Useful for comparing output of your program to 'gold output' (AKA expected/correct output) diff - answer- Report differences - Useful for comparing output of your program to 'gold outpu