What is White Box Testing? – The Basics You Need to Know

What is White Box Testing? – The Basics You Need to Know

What is all this talk about test cases, White Box Testing, conditions, and loops? And how are you supposed to understand all these terms and ideas? We know software testing is complex and confusing, especially if you’re not a software developer. But we’ve got you covered.

Within this article, we’re breaking down White Box Testing in an easy-to-understand but information-rich way. We’ll discuss the definition of White Box Testing, how it compares to black box testing, and how to get started with White Box Testing. We’ll even cover the consequences of skipping White Box Testing altogether, leaving your customers to rely on your Instatus status pages. Instatus is a great tool to keep your customers updated during unforeseen incidents and outages. It is not designed as a crutch for poor testing methods. With this guide, you’ll learn all the basics you need to know to get your White Box Testing process off the ground.

What is White Box Testing?

White box testing, sometimes called glass box testing or clear box testing, focuses on testing a software application's infrastructure and internal coding. Essentially you’re looking through the application’s outer shell or appearance to peer into the inner workings of the software, which is where the name comes from.

White box testing is done manually or using automation tools. Developers test the internal code using different test cases to check the overall quality of the coding.

Black Box versus White Box Testing

While White Box Testing is about taking a close look at the internal workings of your software, Black Box Testing doesn’t care about that. Black Box Testing involves only the testing of external behavior.

Usually, the tester knows nothing about the internal structure or implementation of the software when performing Black Box Testing. Your QA department is usually responsible for this form of testing. It’s quicker and far less exhaustive than White Box Testing but still serves a vital purpose.

A tester will interact with the software, testing the application's behavior to ensure everything functions as intended. They’ll select valid and invalid inputs for outputs. Are the drop-down menus working? Is everything redirecting correctly? Are there any broken buttons? Does the application meet all project requirements? Does the application run smoothly on the intended systems?

Performing White Box Testing

How do you go about performing White Box Testing? Where do you start if you’ve never implemented this style of testing before? Here we’ll cover the best practices and steps involved in successful White Box Testing.

1. Familiarity with the Code

White box testing involves carefully breaking down code sections and testing them for validity and quality. A tester must be intimately familiar with the coding language and the internal structure of the code. If the tester is not adequately comfortable within the code base, they will not write the best test cases. This means a higher chance that critical bugs or security vulnerabilities are missed.

Choose one of the strongest developers on your team to lead White Box Testing, so you know that the application receives 100% coverage.

2. Types of White Box Testing

White Box Testing is broken into small sub-types for different test cases. Ensure your team is familiar with these test types and uses them where applicable:

• Unit Testing – a unit is the smallest testable section of code. A unit should be able to function and perform independently as intended.

• Loop Testing – loops are used everywhere in a program's algorithms. This form of testing looks for mistakes or vulnerabilities within loops.

• Penetration Testing – penetration testing is a vital part of testing an application for security vulnerabilities. A tester can access all network maps, credentials, and other information to mimic a real cybersecurity threat and identify vulnerabilities within the network.

• Performance Testing – tester may use tools like Rational Quantify (for C/C++ programs, there are other tools for other languages) to visualize what sections of code take longer to complete and which areas of code are efficient. This information helps your team understand bottlenecks within your application so they can be addressed to improve overall application performance.

• Conditional Testing – conditional testing focuses on testing every condition (if x then y) within an application. Conditional testing provides the best coverage to ensure even complex conditions are checked.

• Path Testing – path testing coverage ensures that each line is thoroughly checked for each possible scenario. Essentially, if an algorithm has multiple possible scenarios, are all possible scenarios valid, and what happens with each.

3. Creating and Executing Test Cases

A tester will break down the entire application into specific categories based on the test cases above. Every line must be isolated into one of these categories to ensure it’s been tested. For example:

• Conditions – conditional statements usually use IF/ ELSE, ELIF, etc, and have a True or False result.

The tester is creating test cases to verify that every component of the application flows correctly, works correctly, and doesn’t break or negatively interact with another component.

4. Fixing the Issues

Once the entire application is broken down and tested, you’ll likely have a list of conditions, loops, and modules that have issues. The module may appear to work on the surface, but one of the test types identified a security vulnerability, unintended consequences, or other problems that need addressing.

Your team can then work through fixing these issues and should run those same sections of code through the test cases again to ensure all problems are resolved.

Consequences of Skipping White Box Testing

White Box Testing is complex. It requires a great deal of knowledge of the programming language, algorithms, security principles, and codebase to carry out successful White Box Testing. Simple applications may only take a few hours or minutes to test, but large applications can take weeks to test thoroughly.

The complexity and time investment are part of why continuously integrating and testing your codebase as you go is so vital. It’s inefficient to way until the entire application is complete to decide it’s time to proceed with White Box Testing.

But your team should never skip White Box Testing. Your application might appear just fine, but underneath the hood, components may interact in ways your developers never intended, and security vulnerabilities may go unnoticed. When you push changes to your customers, these issues lie in the background, ready to cause all sorts of problems.

If your application’s uptime starts diminishing and users rely on your status page, like those provided by Instatus, to understand what’s going on, you’ve got a problem. If you haven’t implemented White Box Testing, now is the time. If you already have, you may need to ensure the process works correctly to identify underlying issues before the code is deployed.

Instatus is a powerful tool for unforeseen circumstances, not a crutch for poor testing processes. The free plan has no subscriber limit, so your entire user base can subscribe to stay updated. Upgrading to the Pro plan for $20 a month allows you to use your organization's domain. And for $300 a month, the Business plan offers everything from the other plans plus SSO/SAML, yearly invoicing, and three Instatus pages.

Wrapping Up White Box Testing

White Box Testing is essential to thoroughly test the internal workings of an application’s code before deploying it to customers. It’s the opposite of Black Box Testing, which looks at the external behavior of software and tests its overall functionality. White Box testing is a complex and time-consuming process, which can be made easier with automation tools. Still, it’s usually overseen by software developers because it requires a strong knowledge of the programming language and familiarity with the codebase.

Developers write test cases to test specific code sections based on their type. If your team doesn’t White Box Test, you will likely miss significant security vulnerabilities, bugs, or other issues. Don’t put your customers in a position where they constantly check your Instatus status page to learn what’s happening. Start implementing a top-tier White Box Testing process today!