Unit 4 testing
- 2. • A Strategic approach to software testing • Verification and validation • Organizing for software testing • Testing strategy for conventional software architectures • Testing strategy for object-oriented architectures • criteria for completion of testing.
- 5. Black box testing and white box testing Every engineering product can be tested in one of two ways. Knowing the specified function that a product has been designed to perform, tests can conducted to perform each function fully and same time searching for errors.(Black box testing) Knowing the internal working of the product, tests can be conducted to ensure all.(white box testing)
- 6. • Black box testing: • It is a method of s/w testing that examines the functionality of an application without looking into its internal structure of working, called an black box testing. • This method is applied at any level of testing (unit,intergration,system,acceptance testing). • These tests are based on requirements and functionality.
- 7. • Another name for black box testing is “behavioral testing” • Black box testing techniques are: • Equivalence partitioning • Boundary value analysis • Cause and effect graph technique • Decision table testing • Error causing.
- 8. • Equivalence partitioning: It is one of the test design technique, used in black box, white box, unit,…… It divides the entire input into partitions and test each partition at once in time. When we pick up a value from valid partition the system should accept the vale.
- 9. • Boundary value analysis: • It is also test design technique and related to equivalence partitioning. • Here we are testing both sides of valid partition, having lower boundary and upper boundary.
- 10. • Cause and effect graph technique: • Cause Effect Graph is a black box testing technique that graphically illustrates the relationship between a given outcome and all the factors that influence the outcome. • cause and graph is based on requirements and situation. • It is also known as Ishikawa diagram or fish bone diagram because of the way it looks.
- 11. • Decision table: • Decision table testing is a software testing technique used to test system behavior for different input combinations. • This is a systematic approach where the different input combinations and their corresponding system behavior (Output) are captured in a tabular form.
- 12. • Error guessing: • Error guessing is a technique on guessing the error which can prevail in the code • It is basically an experience based technique • Where the test analyst uses his/her experience to guess the problem in application.
- 13. • White box testing: • White box testing sometimes called as glass-box testing or transparent testing. • Using white box testing methods the s/w engineer can derive test cases • guarantee that all independent paths within in a module have been exercised at least once • exercise all logical decisions on their true and false sides. • execute all loops at their boundaries and with in their operational bounds • exercise internal data structures to ensure their validity
- 14. • Basis path testing • Control structure testing. • In basis path testing they are • flow graph • independent program paths • deriving test cases • graph matrices
- 15. • Step 1: consider program structure • step 2: program structure is translated to flow chart . step 3: flow chart must be converted to flow graph.(flow graph having nodes and edges). step 4: find cyclomatic complexity step 5: find independent paths a)how many no. of times that paths are executed.
- 16. Validation testing Verification :did we built the product right. Validation :did we built the right product. Def: validation succeeds when s/w functions work in a manner that reasonably expected by customers.
- 17. Validation test criteria: A test procedure defines specific test cases, It ensures that all functional requirements are statisfied, all behavioral characteristics are achived, all performance requirements are attained, documentation is correct, and usability and other requirements are met.
- 18. • Configuration review: • The intension of these review is to ensure that all s/w configuration have been properly developed. • some times called an audit • Alpha and beta testing: • Alpha test is conducted at developer’s site by end-users • Alpha tests are conducted in a controlled environment.
- 19. • Beta testing is conducted at end-user sites. • The end-user records the problems that are encountered during test
- 20. • System testing • System testing is actually a series of different tests whose primary purpose is to fully exercise the computer based system. • Recovery testing: • Recovery test is a system test that forces the s/w to fail in variety of ways and verifies that recovery is properly performed.
- 21. • Security testing: it verifies the protection mechanisms built into a system,infact to protect it from improper penetration. • Stress testing: • Performance testing: the performance test is designed to test the run-time performance of s/w.
- 22. The art of debugging Debugging is not the testing, is an art Debugging occurs as a consequence of successful testing. Debugging is the action that results in removal of error. Debugging process: Process begins with the execution of test cases Results are, lack of correspondence b/w expected and actual performance. Debugging attempts to match symptoms with cause
- 24. • Debugging have two out comes • cause will found and corrected • the cause will not found, in later cases the person performing debugging may suspect a cause. • They are three debugging strategies. • 1)brute force • 2)backtracking • 3)cause elimination
- 25. • Brute force: • The brute force category of debugging is probably the most common and least efficient method for isolating the cause of a software error. • We apply brute force debugging methods when all else fails. • Using a "let the computer find the error" philosophy,
- 26. • Backtracking • Backtracking is a fairly common debugging approach that can be used in small programs. • where a symptom has been uncovered, the source code is traced backward (manually) until the cause is found.
- 27. • Cause elimination • Data related to the error occurrence are organized to isolate potential causes. • A "cause hypothesis" is devised and the aforementioned data are used to prove or disprove the hypothesis. • Alternatively, a list of all possible causes is developed and tests are conducted to eliminate each.