The Explanation of White Box Testing
White box testing, otherwise known as transparent, glass box, or structural testing, is a methodology for testing that entails assessing the source code and the inner structure of a software.
Recommended IPTV Service Providers
- IPTVGREAT – Rating 4.8/5 ( 600+ Reviews )
- IPTVRESALE – Rating 5/5 ( 200+ Reviews )
- IPTVGANG – Rating 4.7/5 ( 1200+ Reviews )
- IPTVUNLOCK – Rating 5/5 ( 65 Reviews )
- IPTVFOLLOW -Rating 5/5 ( 48 Reviews )
- IPTVTOPS – Rating 5/5 ( 43 Reviews )
The main focus in white box testing is the inspection of the code structure and verification that the internal operations conform to the stated requirements. Further, it aims to meticulously examine all internal parts.
After spending nearly ten years in software testing, I have observed that testers are among the most passionate professionals in the software business.
Their passion emanates from the perpetual learning possibilities they have. Testers always have something new to explore, be it a domain, a procedure, or a technology. They can cultivate a comprehensive set of skills if they desire.
Nevertheless, every profession has its downside. Testers often veer away from white box testing, misinterpreting it as convoluted and something primarily within developers’ scope.
White Box Testing concentrates on the following areas to cover:
1. Code coverage: Evaluate the reach of the code.
2. Segment coverage: Make sure to execute each line of code at least once.
3. Branch Coverage or Node Testing: Complete coverage of each code branch from all plausible angles.
4. Compound Condition Coverage: Probing of each condition with a variety of paths and mixes to reach that condition.
5. Basic Path Testing: Inspection of each autonomous path in the code.
6. Data Flow Testing (DFT): Observation of specific variables through each potential calculation for identification of dependencies and verification of their justified usage.
7. Path Testing: Construction and coverage of all potential paths through the code.
8. Loop Testing: Examination of single loops, concatenated loops, and nested loops to ensure their adequacy of functionalities.
Motives for Implementing WBT
The implementation of White Box Testing aims to:
- Guarantee that all standalone routes within a module are tested.
- Confirm the accuracy of logic-based decisions.
- Examine the boundaries and functional capacity of loops and internal data structures.
White Box Testing assists in detecting the following types of issues:
- Logical errors that transpire during the design and implementation of functions, conditions, or controls in disagreement with the software’s requirements.
- Design errors that originate from differences between the logical stream of the software and its actual execution.
- Typographical mistakes and syntax checking problems.
Necessary Programming Skills
To properly execute White Box Testing, testers are required to draft test cases that encompass the entire software logic.
This obliges a comprehensive grasp of the software, inclusive of its specification and code. Testers ought to have a knowledge base of programming languages and logic to perform this form of testing.
Testing every path of loops in a large software is not feasible. Exhaustive testing is inefficient in such instances.
Nonetheless, this does not negate the potency of White Box Testing. By selecting crucial logical paths and data structures for testing, impactful and practical testing can be accomplished.
Contrast Guide of White-Box and Black-Box Testing
In unambiguous terms, Black Box Testing concentrates on a user’s outlook of testing the software, while White Box Testing involves a detailed examination and testing of actual code.
In the case of Black Box Testing, the internal system code stays invisible, whereas in White Box Testing, the internal code is available for inspection and testing.
White Box Testing is employed by developers and testers equally to comprehend which lines of code have been executed and which ones have not. It aids in identifying missing logic or typographical errors that could have adverse effects.
Suggested read => An inclusive guide to Black Box testing
Instructions to Execute WBT
Step #1: Comprehend the application’s functionality with the help of its source code. Testers ought to have a mastery of the programming language along with other software development tools and procedures.
Step #2: Draft and execute tests.
When it comes to testing, “coverage” is fundamental. Maximizing coverage is a pivotal aspect of White Box Testing. Here, I will expound on how to reach maximum coverage in the context of White Box Testing.
Worth reading => Cause and Effect Graph – A Prolific Method for Writing Test Cases for Optimal Coverage
Categories and Methodologies of White Box Testing
White Box Testing comprises assorted types and methodologies.
Refer to the image underneath for a graphic representation:
In this write-up, our central focus will be on the execution testing varieties of the ‘Unit testing white box procedure’.
3 Main White Box Testing Methodologies:
- Statement Coverage
- Branch Coverage
- Path Coverage
It’s crucial to note that whether it’s statement, branch, or path coverage in solitary, they do not identify issues or defects that need rectification. They merely recognize lines of code that are untouched or were never executed. Subsequent testing can be concentrated on those areas.
Let’s comprehend each of these methods with a basic example.
#1) Statement Coverage:
A statement in programming signifies a line of code or directive that the computer carries out. An executable statement is one that compiles into object code and executes an action during the program run.
“Statement Coverage” involves validation to ensure each line of code has been executed a minimum of once.
#2) Branch Coverage:
A branch in programming, e.g., an IF statement, can possess two branches: true and false.
In Branch Coverage, alternatively known as Decision Coverage, the aim is to validate that each branch has been executed a minimum of once.
For an IF statement, it requires an individual test for both the true and false branches.
#3) Path Coverage
Path Coverage necessitates testing of all possible routes within a program. This technique ensures each path is traversed a minimum of once. Path Coverage surpasses the power of Branch Coverage and is specifically beneficial for testing intricate software.
Let’s take a rudimentary exemplification to demonstrate these White Box Testing methods.
Further consultation => Diverse Types of testing
Instance of White Box Testing
Let’s suppose the following basic pseudocode:
INPUT A & B C = A + B IF C>100 PRINT "ITS DONE"
For Statement Coverage, only a single test case is required to cover all the lines of code.
If we consider TestCase_01 as (A=40 and B=70), then all the lines of code get executed.
Now, consider the following:
- Is that enough?
- What if we were to regard TestCase_02 as A=33 and B=45?
Statement Coverage alone is inadequate for testing the entire pseudocode. We need to consider negative cases as well.
For optimal coverage, we need “Branch Coverage”. Branch Coverage makes sure both the true and false conditions are tested.
So, with the updated pseudocode considering Branch Coverage, two test cases would be required:
TestCase_01: A=40, B=70
TestCase_02: A=33, B=45
By using these test cases, we can ensure that each line of code gets executed at the very least a single time.
Here are the conclusions we can draw:
- Compared to Statement Coverage, Branch Coverage ensures more coverage areas.
- Branch Coverage is more effective than Statement Coverage.
- 100% Branch Coverage implies 100% Statement Coverage.
- However, 100% Statement Coverage does not ensure 100% Branch Coverage.
Now let’s proceed to Path Coverage:
As stated previously, Path Coverage is employed to test complex codes that involve loops or combinations of loops and decision directives.
For example let’s consider the following pseudocode:
INPUT A & B C = A + B IF C>100 PRINT "ITS DONE" END IF IF A>50 PRINT "ITS PENDING" END IF
To gain maximum coverage, four test cases would be required.
Why? There are two decision directives, so for each decision directive, we would need to test two branches (one for the true condition and one for the false condition). That makes a total of four test cases.
Let’s simplify this by considering the following flowchart:
To achieve full coverage, we need the following test cases:
TestCase_01: A=50, B=60
TestCase_02: A=55, B=40
TestCase_03: A=40, B=65