Even though a growing number of businesses are embracing digitization to stay relevant and grow in a tech-driven economy, modernizing legacy applications has become crucial. Although considered obsolete, old systems store huge databases, customer records, financial records, and other sensitive corporate data. Therefore, when adopting modernization, it is essential to contact experts and ensure that effective software testing is carried out to ensure not only data loss, but also cost-effective and efficient system integration. that can help add business value to organizations.
To elaborate, the need for legacy application testing results from a number of factors, including but not limited to the need to reduce a product’s time to market, maintenance costs and usage related to technologies used in legacy applications, and other aspects such as a reduced ability to automate routine manual tasks due to restrictions on technologies such as mainframes and the tools available to do so. However, the testing process can be challenging and encounter various obstacles, making it imperative that the task be performed by experts who can operate and run the program, contribute their knowledge, expertise and experience. particular processes, software techniques and skill sets, as well as the choice of relevant tools.
Some of the key aspects that a software testing team should address include:
Identification of potential sources of information:
Finding sources of knowledge about the system under test is crucial because the documentation may be hard to find or outdated. Since a single individual is unlikely to have all the solutions, companies should be proactive in seeking knowledge and assisting the software testing team with all potential resources to ensure adequate knowledge transfer.
Understand system dynamics for effective integration:
Given the complex dynamics of integrating legacy and contemporary technologies, it is essential that software testing experts be familiar with the nature of old and new systems. Given the lack of documentation in some cases, it is important to have a team that can decipher and understand the system from a technical perspective and answer questions that can help with test automation. What are the most common environmental issues in the project? What are the main integration issues related to system-to-system communication? What aspects of business logic cause the most conduction? etc
Determine what should be automated and what should not:
Test automation can help simplify the life of any project, especially when it comes to testing large legacy applications. On the other hand, automation is not a silver bullet that magically solves all problems. It can actually make things harder, even with just one wrong move. Trying to automate everything, automating without properly analyzing the system under test, investing too much in UI automation, not considering complex system integrations, having unreliable test data, and working with unstable test environments are all examples of undesirable approaches to test automation.
Best practices for testing legacy applications:
The desire for 100% test coverage is a practice that developers should abandon:
Since companies don’t test regular code, developers can’t focus on getting 100% coverage. Unit testing for legacy code in general. Legacy codebases are huge and complex. Focus on “big” testing like integration and functionality testing instead of striving to test every loop in every method of every class. Switch contexts frequently and ensure that all tests pass without modifying the template code as usual.
Application usability and efficiency should be at the heart of modernization:
When embarking on legacy application testing, there must be a clear understanding not to lose or diminish the usability/efficiency of the application. Often, testers can get so wrapped up in the process and assume that modernizing it will automatically equate to increased efficiency, that presumption can lead to massive setbacks.
Include testing in your CI/CD process:
CI/CD pipelines ensure that every save to the code repository triggers automated test execution and that new changes do not break current functionality. Continuous integration (CI) allows companies to release new features faster. Using any language or tool, create a set of tests (test suite) for each class in the legacy application.
Invest in technical documentation:
Technical documentation is best practice in software development as a whole, although most companies provide it for the following reasons: Whenever a rewrite is needed or an existing feature has changed. while improving existing features and introducing new ones; The biggest problem that documentation solves is the amount of less work needed for maintenance and creating new features.
This general approach can help a legacy project dramatically increase test coverage and understanding. Once you have a baseline, you can refactor the application with the assurance that you’re not breaking anything using other software development techniques. The goal is to standardize the application to the point where you can start relying more on industry standards and characterization testing. When you get to this point, you can start removing the harness because it has served its purpose.
Opinions expressed by: Sumana Iyengar, CEO and Co-Founder, Goavega Software Pvt. ltd.