QA Testing - why do you use stubs and drivers in top down and bottom up approaches , how do they help

GeekInterview.com > Interview Questions > Testing > QA Testing

Go To First | Previous Question | Next Question

QA Testing | Question 136 of 176

why do you use stubs and drivers in top down and bottom up approaches , how do they help

Total Answers and Comments: 2

Last Update: December 09, 2007 Asked by: viiram845

Sponsored Links

Best Rated Answer

—

No best answer available. Please pick the good answer available or submit your answer.

October 28, 2007 10:39:28

prabhakar

RE: why do you use stubs and drivers in top down and b...

Drivers are the readymade programs that instructs the hardware.

Is this answer useful? Yes | No

December 09, 2007 02:22:22

dilton_dalton

Member Since: December 2007 Contribution: 14

RE: why do you use stubs and drivers in top down and bottom up approaches , how do they help

Stubs are replacements for called routines (object methods) that reproduce the behavior of the replaced routine to some level of fidelity. A stub may return after doing nothing or it may check the inputs and return a status or it may return predefined constant values in place of real values or it may return different values that depend on how many times it is called. A stub may replace an entire subsystem. There are a number of other terms used to describe stubs depending on their characteristics. Not everyone agrees on these terms.

Drivers are programs that are designed to call routines or methods that cannot be compiled and linked on their own. The purpose of drivers is to provide test data to the items being tested. A single driver can incorporate many test cases and could be tied to a database that collects test results (test number inputs outputs expected outputs returned status execution time pass/fail test date testers name ......)

Top down and bottom up refer to integration strategies. In the top down approach the first real software item to be used is the main program. All of its calls are replaced with stubs and it is tested. Then one stub is replaced with a call to a real method. That method will have stubbed out calls as well. Only items that have passed the prescribed verification processes can be used in the integration. This process proceeds until all of the stubs have been replaced with tested production software.

In the bottom up integration approach a number of drivers are used to test the lowest level calls. Then the lowest level methods are used instead of stubs to test the next level of methods. First subsystems built and tested and then they are but together and tested. This process is repeated until the entire system is integratted. The last item to be intergrated is the main program. The advantage of the bottom up process is that not as many stubs need to be produced and components do not have to be unit tested before integration. The disadvantage is that a lot more drivers need to be produced. If there are problems found post release reintegration of the repairs can take more effort in the bottom up approach but the differences are not great.

Producing and saving stubs and drivers for unit testing and integration provides an invaluable tool for maintenance efforts.

Is this answer useful? Yes | No

SQA Approaches and Methodologies

SQA Approaches and Methodologies A scientific approach should have methods As a scientific process a stage or a step should be established or used to ensure the final product is according to the user’ s specifications The method is usually determined through the wishes of the clients the a

What is Business Drivers

Business drivers are the people, information, and tasks that support the fulfillment of a business objective.  They lead the company trying to get it away from pitfalls and turn unforeseen mistakes into good lessons for future success and sustainability. A business needs to be constantly dr

Testing and Integration

Once the software is complete, it will go though rigorous testing before its actual integration.  In this article we will take a look at different types of software testing and also different types of integration. With the diversity of business setting and software development models, it al

The Interview Snafu

How to turn someone else’s mistake to your advantage Your dream job is about to become reality. A recruiter gave you the heads up about the perfect position at Humungous Conglomerate, Inc. You went through five interviews as well as a battery of psychological tests mandated by their HR de

Winning a Job Interview with a Winning Resume

Does your resume unlock your potential, take your skills to the highest level and win you the interview and the job you want now? The job market today is highly competitive and even if you think you have what it takes to get an interview you won’t get over the line without a polished, prof

Client-Server Testing Technology

Client Server Testing Technology Client Server Software Client server software requires specific forms of testing to prevent or predict catastrophic errors Servers go down records lock I O Input Output errors and lost messages can really cut into the benefits of adopting this network technology Test

Importance of Proper English during Job Interview

Importance of Proper English during Job Interview Your job interview is crucially important and it will determine whether or not you will get the job Depending on the type of job you re going for it is very important for you to use proper English In most cases jobs which offer higher salaries will h

HR Interview - HR Interview Mistakes You Will Want To Avoid

HR Interview Mistakes You Will Want To Avoid The job interview can be a stressful process This is especially true for those who are going after a competitive position Your nonverbal communication combined with the answers you give during the interview will determine if you are hired mosgoogle While

Software Testing Myths

Software Testing Myths Any IT professional is sure to know the different phases of the Software Development Life Cycle or SDLC namely Feasibility Study Requirement Analysis Design Construction or Coding Testing Implementation Maintenance Support the activities carried out in each phase their sig

HR Interview - Behavioral HR Interviews

Behavioral HR Interviews As the name implies a behavioral interview is an interview that is held by a human resources department to determine if an applicant has the behaviors that are appropriate for a job The company must know how an applicant will behave in a certain situations mosgoogle The logi

Related Categories

—

User Name		Remember Me?
Password

Question Bank