How White Box Testing Impacts Legacy Software Applications by Garth Rose on Dec 20, 2016

A legacy software application is a mass of source code written to run on older hardware, languages, and sometimes even outdated operating systems. What’s holding these applications back from being re-written in a modern application framework? The risk of a “working” legacy application becoming bug-ridden and broken.

The Risk of Updating

When a legacy application is being updated, there may be millions of lines of code migrated or rewritten. And within the millions of lines of source code, there exists thousands of functions and methods containing simple to complex business logic. During the process of the code migration, much of the source code will go untested. An inevitable mass of bugs will creep into the code base with hidden disasters waiting to wreak havoc once the software is released into production.

To both engineers and management this sounds like a scary and risky endeavor. Who would want to migrate an application to a new framework if it took years to get the existing application debugged and running smoothly? This is why old legacy software applications still exist, running on old expensive, outdated hardware, and obsolete operating systems.

Mitigating the Risk

So, how do we remove this paralyzing fear of updating a legacy application and keeping it relevant? We get there by fully white box testing the source code. White box testing is the only way to accurately, efficiently, and smoothly move a legacy application to a new language and modern application framework. Legacy applications are too large and complex to test with just black box (functional) testing. With white box testing, you can ensure every function, every method, and every line of simple to complex business logic is fully tested as it is being migrated to the new system.

Automated White Box Testing to the Rescue

Unfortunately, few organizations do white box testing because the tests are so slow and complicated to write, however, GenRocket is uniquely able to help tackle this white box testing challenge. GenRocket enables automated white box testing which enables full testing of software applications. Full testing of the software enables legacy software applications to be migrated or rewritten to a new language, modern application framework, new hardware, and even a new operating system without the risk of bugs. Not only does GenRocket make it easier to write white box test cases but significantly speeds up the process. One of our quality engineers was able to write 770 white box (integration) tests in a month compared to the industry norm of about 40 white box tests.

To learn more, visit our Automated White Box Testing Solution Page.