The Importance of Component Testing for Financial Apps

When it comes to testing the performance of their applications, retailers have somewhat more of a predictable workload. They already know the busy times – Black Friday and the week before Christmas, for example. This makes capacity planning and software testing more straightforward. 

The financial sector, on the other hand, doesn’t have this luxury. High demand for financial services can be triggered by any number of unexpected events, such as large changes in the stock market, natural disasters, or major world events.  

This means that financial applications and systems must be ready at all times to handle higher-than-normal traffic (nothing new here: in the pre-Internet stock market crash of 1987, many onsite telephone systems were ill-equipped to handle the unexpected volume of calls from distraught clients). To ensure apps are ready, component testing is vital. 

This blog will discuss what component testing is, the four pillars of component testing, and why BlazeMeter is the unparalleled leader in ensuring superior financial app performance under all types of stress and load. 

What is Component Testing?

Component testing is a method of software testing that evaluates the functionality of a program without taking underlying code into account.  

An example of component testing is if an application has a login screen and requires a username and password. Test the login functionality to ensure that a successful login occurs with the correct username and password or — on the flip side — a login fails with the incorrect username and password. 

It is a mistake to think of performance testing as an isolated afterthought to be done when a project is completed. It should instead be embedded in every step of the development process, and performance testing should be thought of as one of the four pillars of testing. 

Four Pillars of Component Testing

Functional Testing

Make sure the functions match the specifications. Test that the software is working as planned — producing a definitive “pass” or “fail.” 

Regression Testing

Confirm no new errors have been introduced. When changes to code are introduced, you need to ensure nothing else within the program breaks as a result. 

Performance Testing

Ensure that performance matches specified criteria. Determine the program’s speed, stability, scalability, reliability, and resource usage. 

Negative Testing

Establish robustness by subjecting the software to unusual and unexpected conditions. Ensure your app can handle and verify invalid input (I.e., incorrect login information). 

The Importance of Component Testing

In addition to considering all four pillars, it is important that these tests are performed well before system integration. This means all four levels of testing should be done at the component level (think of these as the blocks of code that make up an app). This is because the details of the code will still be fresh in the developer’s mind should any problems arise. Plus, the more thoroughly the components are tested, the greater the probability of a swift and successful system integration. 

Testing should also be embedded in the development process: not having developers hand over components to an isolated testing team. Ideally, an environment will be created for testing each component, which will go a long way in ensuring each facet of an app functions correctly. 

Under-utilized Component Testing: Negative Testing 

Negative testing is the one pillar that doesn’t get as much attention as it should. These tests should include out-of-bounds conditions (where the values exceed specified ranges), improper data values (such as having alphabetic characters in a numeric field), and unexpected asynchronous calls (where the component is called when it does not expect to be called). 

Mock services are a great tool for negative testing. They can simulate a service that is slow, a service that returns invalid data, and a service that returns unexpected responses. There may be third parties that are part of the process (in the case of a bank, this might also include other departments). Again, a mock service can be used for positive, negative, and performance testing in place of a live third party. 

The goal of negative testing is to ensure that each component in the application will handle problem conditions in a robust and orderly manner. For example, the typical user will be most unhappy should a mobile app or web page remain unchanged for more than three seconds. Should a mobile gateway not respond within three seconds, the mobile app should display a message saying the processing is still taking place. A slow mock service simulating the mobile gateway allows this sort of test to take place. 

The Benefits of Continuous Component Testing

The criticality of performance testing cannot be overstated. Simulating load on a large number of devices can be used to gather information about the end user experience when the system is under load. 

When performance testing is performed at the component level, the system architect can specify the expected performance of each component. Should component-level performance testing reveal that the component is not meeting the desired level of performance, it can be dealt with quickly, rather than not being exposed as a problem until final performance testing is done when changes are much more difficult. 

After the application components are developed and tested, the same four pillars will apply to system integration testing. 

Once a new project has been placed into production, testing should still continue. Testing should consist of periodic maximum load tests to ensure the availability of the entire system when there is an unexpected load. Charles Schwab, for example, regularly conducts high volume tests so that if there is a stock market disruption, their online systems have been proven to handle the extraordinary load. 

Sometimes when a bank closes, it is the result of the inability of a financial institution’s systems to handle an unexpected load. This could potentially bring about questions about the financial institution’s viability. In today’s banking world, rumors can cause electronic bank runs. The speed of withdrawals can quickly overtake a scramble to fix a capacity problem. It is better to thoroughly test performance before a crisis creates a surprise.  

Performing the four pillars of functional, regression, performance, and negative testing at the component level — and periodically at the system level — can go a long way to building confidence in a financial institution’s technology, the quality of its apps, improving the customer experience, and preparing for the unknown. 

Bottom Line

The performance and overall user experience of your app is the easiest way to lose a customer if it is not prepared properly. Glitches, bugs, long load times, and outright crashes will tarnish your brand’s reputation and cause customers to seek out your competition. 

With BlazeMeter, you can rest assured that your financial app will be ready for whatever the world throws at it. Whether it’s peak traffic events, major world events, or natural disasters, feel confident that your app is up to the task. 

What are you waiting for? You can start testing with BlazeMeter for FREE today! 

Start Testing Now 

Adapted from our FinExtra article published June 12, 2023.