White box testing is a type of testing technique that aims to evaluate the code, design and the internal structure of a program to improve its design, usability and security. It is one of the two parts of Box Testing methodologies included in software QA testing.
The term “white box” is used to refer to the concept of the see-through box. Simply put, the clear box, or White Box symbolizes the ability to look through the outer shell of a program and into its inner layout.
In this guide, we’ll discuss everything you need to know about white box testing, how it is done, its pros and cons, and the best tools available to do it.
When white box tests are carried out correctly, they can identify the following issues and concerns in the code of an application:
To provide you with a simple explanation of how experts perform white box testing, we will talk about the process in two steps.
The following are the primary tasks testers do when applying the white box testing approach:
One of the first things testers will do is study and understand a program’s source code. Since the inner workings of a software application are being tested in white box testing, these testers need to be highly experienced in the various programming languages as well as secure coding practices.
Since security is one of the main goals in testing software, testing experts should be able to identify security concerns to prevent attacks from cybercriminals and users who may accidentally insert malicious code into the program without knowing.
The next step involves testing the source code of an application to see if its flow and structure work properly. One way testers perform this is by writing additional code so they can test the program’s source code.
Testers develop minor tests for every process or series of processes within the app. This step requires testers to have in-depth knowledge of the code, which is why it is usually performed by the developer.
The following are the most popular techniques used in white box testing:
One of the primary objectives of white box testing is to make sure that the source code is covered as comprehensively as possible. That is why the metric code coverage is used as it shows how much of a program’s code has tests to check its functionality.
Using code coverage allows testers to verify how much logic is actually being executed and tested using the unit test suite for a given application.
In branch coverage, testers map the code into different branches of conditional logic. This is done to make sure that each of these branches is covered by the unit tests.
The tester identifies all unconditional and conditional branches in a branch coverage approach and then writes the code to execute as many of these branches as they can.
The path coverage approach concerns itself with the linearly independent paths present in the code. A tester maps out the code’s control flow diagram which is then used to design the tests in this technique.
The tester also writes unit tests and executes as many of them as possible and uses the control flow of the program to achieve this. The main goal here is to identify any inefficient, redundant, or broken paths.
Lastly, statement coverage is a technique in white box testing that ensures every executable statement in the code is run and tested at least once.
The goal of statement coverage is to help identify unused branches, unused statements, dead codes, and missing statements.
There are several testing types in white box testing that are used to evaluate the usability of a program, software package, or block of code.
As stated earlier, white box testing and black box testing are two different methods of application testing. Here are the differences between the two:
Parameter | Black Box Testing | White Box Testing |
---|---|---|
Definition
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Black box testing is a testing approach that tests the software without knowing its internal structure. The main focus here is the end-user experience
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White box testers know the internal coding of the program
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Objective
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The main objective of this kind of testing is to check the functionality of the system under test
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White box testing ensures that the code quality is up to standard
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Base of testing
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In black box testing, the testing is based on external expectations
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Internal programming of a software is known in white box testing
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Usage
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Black box testing is great for higher levels of testing such as in acceptance and system testing
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White box testing is ideal for a lower level of testing such as integration and unit testing
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Testing Method
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Black box testing is based on trial and error
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White box testing can look into data domains and internal boundaries
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Programming Knowledge
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Black box testing does not require any programming knowledge
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Programming knowledge is required to perform white box testing
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Time
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It is less exhaustive and time consuming
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It is very exhaustive and time consuming
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Benefits
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It is well-suited for large code segments
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It helps to remove all extra lines of code, that might give rise to extra defects
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Drawbacks
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It becomes necessary to update the automated test script with every modification to the application
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Automated test cases become redundant if there are frequent changes made to the code
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Helps in code optimization
Can be easily automated
Testing is thorough
Testing can start early in the SDLC phase
Here are some of the most popular tools used in white box testing:
White box testing is a complex testing procedure that requires testers to have in-depth knowledge of the application’s code. Compared to black box testing, white box testing focuses on the inner workings of the software program being tested.
The information in this guide should help give you a better idea of what white box testing is about and its importance in the quality assurance process. Partnering with QASource for white box testing ensures that you get a high-quality, affordable, and reliable experience. Get in touch today!