How on earth do you run integration tests checking multiple software modules coded by different programmers if one of those modules is not yet built or is being used elsewhere? Typically, you can’t.
As today’s software becomes more complex, built on API-driven apps, cloud-based apps and service-orientated architectures, it creates more dependencies when it comes to testing. For software teams that want to achieve quality at speed, dependencies can spell disruption in the shape of delays.
Mature quality engineering (QE) teams avoid such holdups by using virtual services that emulate the behavior of critical components that are missing or unavailable. This enables them to outsmart obstacles and achieve their goal of implementing testing earlier in the development process – in effect, shifting their testing left.
Here’s what you need to know about using service virtualization to remove the major roadblocks that are preventing your testing shifting left.
Testing dependencies and their associated headaches can occur for many reasons but usually come in two forms, internal and external. These typically encompass components that are:
The key factor here is not to recreate and build every element and function of the real service that you want to virtualize. All that is needed is the basic transactions or calls required for the test cases you’re looking to support so that you can implement shift-left techniques.
Having identified the scenarios when you might use service virtualization, let’s look at why your testing should shift left – spoiler alert: it’s all about switching from problem detection to problem prevention while delivering quality products on time and on budget.
Many software projects follow a traditional waterfall methodology, which is linear, sequential and places testing towards the end of the software development lifecycle (SDLC). If all goes to plan, this structured approach keeps projects flowing forward step by step.
Too often, however, testing becomes an afterthought in the waterfall model and the last few days of any project a scramble. Testers struggle to squeeze in sufficient testing, while developers are left frantically finding, fixing, and often rebuilding whatever defects testing finds. All of which is the perfect recipe for compromising quality and missing release deadlines.
By contrast, and as the name suggests, shift-left techniques take tasks that are traditionally performed later in the SDLC – such as testing – and introduces them earlier and, critically, throughout the SDLC. The overarching principle is that in order to get a quality product out at the end, you need to shift left and bake quality into your project from the start – in agile environments, sprint by sprint.
This change in testing philosophy is commonly summarized as “test early and test often” and involves a step up in company culture as much as in QE processes. In a nutshell, in order to test earlier, your testers and developers need to collaborate sooner and more closely.
In mature DevOps teams, shifting testing left means that automated testing is implemented from the get-go in frequent cycles that match every software increment. So, rather than spotting serious problems so late that they become a major headache, teams find them earlier, and most times, prevent them occurring at all.
This looks great on paper, especially as it comes with a promise to deliver better products faster while saving you money. But the realities of testing sooner and more often can be fraught with dependencies, so tricky to pull off. This is where service virtualization steps in to remove dependencies by mimicking or simulating the behavior of components that are missing or difficult to access while testing.
Think of the film or TV stand-in who substitutes for the actor before filming while the technical team sort out the lighting and camera setups. Or, a surgeon faced with a difficult procedure, who without a human specimen to practice upon, refines their operating technique using a digital model instead.
Service virtualization tools let you quickly spin up a service that allows development and testing teams to perform more work in parallel. This unblocks the development pipeline and delivers distinct advantages, including:
Service virtualization avoids testing bottlenecks and enables the entire team to adopt more streamlined development processes, which ensures faster product delivery.
By using service virtualization to test earlier, defects are also found and can be fixed earlier, which saves you time and money.
Get service virtualization and shift-left techniques right and security shifts left too, mitigating risk and speeding up time to release.
Service virtualization can lead to a better-quality product by giving testers an earlier and better understanding of the app and the time to write and implement more test cases.
Service virtualization also gives the testing team more flexibility, enabling you to avoid the limitations of dependent systems.
Testing early and often using service virtualization gives you scope to also fail early and often, instead of failing spectacularly on or just before a final release date.
Inevitably, software teams run into roadblocks where components such as APIs, third-party apps, databases, mainframes, cloud servers, networks and more are blocked for testing purposes. This can cause delays that lead to missed production deadlines, which can be eye-wateringly expensive.
Service virtualization emulates the behaviors of these missing or hard-to-test components, removing barriers to enable your development team to shift their testing left and adopt more agile workflows.
Best practices for using service virtualization mark a significant step change in the way organizations create a meaningful agile or DevOps environment. This begs specialist technical skills and knowledge of what service virtualization can do to meet the challenge or challenges you’re facing.
If you need help on your agile transformation journey, our experts are ready with strategic consultancy and innovative processes that ensure your quality assurance remains focused on your business goals and the end-customer experience, while speeding up your delivery pipeline.
