Don’t Take Software Integration Testing for Granted – Run It Like This

What Is Integration Testing in Software Engineering

The best way to explain integration testing in software engineering is to compare it to its cousins, so to speak.

First come unit tests.

They’re conducted to check how the fundamental aspects of software work. You take the smallest elements of a program (units) and execute them to ensure that the basics are functional.

Next are integration tests.

Integration testing verifies the interactions between components to ensure they work together. Basically, you gather up related units that comprise a module and determine whether they cooperate with each other.

Last but not least, system testing.

It evaluates the entire integrated software system to secure designed performance and fulfilled requirements.

So, imagine you’re making a bead bracelet. First, you examine each bead individually, say their shape or color. Then, you take a look at a couple of them combined to figure out whether you like the direction your creation is going. And once you’re almost finished, you inspect the entire bracelet to figure out if everything is in harmony.

And that’s what software integration testing is. It’s the middle step that makes sure your product’s parts are well connected before allowing them to work in unison as a whole. By running software system integration testing, you’re:

• Validating that individual software modules work jointly.
• Addressing integration issues, such as data flow or communication errors.
• Verifying that integrated components handle edge cases and error conditions.
• Assessing system performance and scalability implications.
• Providing confidence in the overall functionality and reliability.

Let’s review a simple example to secure what we’ve covered so far.

Say you’re working on an e-commerce store.

• A unit test would assert that a function can calculate the total price of items in a shopping cart – your basic operation.
• An integration test would check the integration between the product catalog and the shopping cart service – your two operations collaborating.
• A system test would ensure the entire e-commerce system runs well, from user registration to checkout.

Overall, you’re examining different levels of your product to guarantee a bug-free state and teamwork at any layer.

Types of Software Integration Testing: Developers vs QA Engineers

Now, it’s common for developers to run integration tests as part of their development process. Especially when it comes to DevOps, Agile, and continuous integration, devs are encouraged to run integration tests to:

• Verify proper integrations.
• Avoid regressions.
• Not miss compatibility issues.
• Support changes to the software.

But that doesn’t mean that QA specialists’ work is discarded.

Perspective & Focus

• Developers often focus on validating that their code properly interacts with other components.
• QA engineers look at the integrations across systems. Ergo, QA experts center on end-to-end scenarios, ensuring that the software as a whole behaves correctly.

Testing Depth & Breadth

• Developers concentrate more on unit-level integration.
• QA engineers perform integration testing at higher levels (interactions between subsystems, databases, APIs, or external dependencies).

Tools & Techniques

• Developers use unit testing frameworks or specialized tools to test integration at the code level.
• QA engineers rely on a combination of tools to verify integration across multiple systems.

Feedback Loop

• Developers typically perform integration testing as part of their development process. They do so iteratively as they integrate new code or make changes.
• QA engineers conduct these tests as part of a broader testing effort. Their goal is to provide feedback on the overall system integration and functionality.

There may be divergent opinions on the approach to the software integration testing cycle.

• Is developer-led integration enough?
• Should only QA specialists run it?
• Maybe integration tests could be divided between the two crews?

Well, as practice shows, teamwork and objectivity are the way to go.

When developers run basic integration tests, they advance their code, improve their skills, and eliminate basic issues. Then, QA engineers join in to check high-level operations, look for missed bugs, and use their perspective to polish the product.

Overall, it’s always better to let QA take care of integration testing. It’s their direct responsibility. They possess the expertise to do it right. And they introduce a fresh, less subjective view of the software to bring it to new heights.

Integration Testing in Software Development Isn’t a Routine Check

It seems that integration testing in software testing is often taken for granted. It may be due to the Testing Pyramid (and its iterations), which established such tests as basics and not “something advanced”.

Or it may be because integration tests fall under functional testing services. You can’t do without them. They’re a staple. So, we don’t discuss them much.

But within QA services, there’s nothing insignificant. From unit to accessibility testing – everything directly (and heavily) impacts your product’s quality.

Things You Should Know About Functional Testing

Use The Hidden Power of Integration Tests to Your Benefit

And so, by not making integration testing a “side dish”, you can:

• Detect issues early enough and at the integration level. In other words, you prevent defects from “growing” and spreading to other layers.
• Ensure system stability and reliability.
• Develop software quality by advancing performance, functionality, and UX.
• Validate end-to-end scenarios to deliver desired outcomes for users.
• Provide confidence in software deployments, eliminating issues before production environments.
• Prevent rework and costly fixes.
• Mitigate risks associated with system integration, such as data corruption, inconsistent behavior, or communication failures.
• Encourage collaboration between development teams by making quality a collective effort.

Consider the Risks Associated with Skipping Integration Testing

On the other hand, if you decide against performing integration tests or don’t pay them due attention, you just might get yourself into a lot of trouble:

• A bigger chance of undetected integration issues.
• A higher number of defects slipping into the production environment.
• Degraded system stability.
• Compromised data integrity or security.
• The need for significant rework that delays product releases.
• Fixing integration issues post-deployment, which is more costly and time-consuming.
• Inconsistent or incorrect behavior in the software.
• Eroded stakeholder confidence and loss of trust and credibility.

With these scary possibilities, you might want to go all in on integration testing. Yet, you don’t have to. You simply ought to allocate enough time and QA resources to cover critical, high-risk, and error-prone elements.

Don’t forget that unit and system testing will help you figure out tiny and more systemic issues. So, it’s better to portion your efforts between these three rather than go berserk on integrations alone.

Organize your work smartly. And you’ll have to do less of it.

Be Prepared to Tackle These Integration Testing Challenges

Depending on your project, integration tests can be a lovely stroll or a downward spiral into chaos. Well, perhaps, it’s all not so gloomy. But integration testing can be quite complicated. Especially for certain niches.

Healthcare systems, for example, commonly require perfect integration. Such software handles unimaginable amounts of data, links with medical devices, and collaborates with intricate hardware. And since it deals with human lives, it indeed has to be utterly flawless.

So, you have to secure remarkable communication between:

• Electronic health records.
• Billing systems.
• Laboratory information devices.
• Imaging software and many more.

Yet, it’s not just the quantity of integrations. Their quality is what matters most. And providing spotless performance for complex products is something only visionary integration testing services can achieve.

Alas, before deciding on how to do integration testing, examine what challenges may lie ahead (informed = armed).

• Integrating various components with different technologies, protocols, or interfaces can make things very complicated.
• Managing relationships between modules, especially in big or spread-out systems, needs careful planning and expert quality assurance.
• Creating and keeping up test environments that accurately mimic production can take a lot of time and resources.
• Making sure data stays consistent and in sync across integrated parts can be tedious and might need special testing skills.
• Linking up with outside systems adds more challenges. You might need to deal with external APIs, data format issues, and limited control over how the system behaves.
• Handling version compatibility in constantly changing environments requires flawless version control and compatibility checks.
• Keeping behavior consistent and compatible across various configurations means testing on lots of different platforms and setups.
• Limited resources can make integrating things harder, leading to difficulties in prioritizing and undermining test coverage.
• Finding the right integration test scenarios and prioritizing them based on risks, importance, and impact can be tough.
• Making sure all integration points, scenarios, and unusual cases are thoroughly tested requires ongoing attention and effort.

We won’t lie. Software integration testing is far from being easy. But, based on our decade of experience as a QA company, any struggle here is worth it.

You wouldn’t want something like what HealthCare.gov went through to happen to you. At the site’s first launch, “Users experienced multi-hour wait times, menus filled with blanks, and [a glitch] which stopped a user from proceeding until they specified how long they had been incarcerated, even if they had never been to prison”.

So, don’t focus on the challenges of integration tests. Figure out how you can overcome them. And employing result-driven software testing services is a good starting point.

Examples of Integration Testing Scenarios You Can’t Do Without

Alright, so if software integration testing is quite intricate, it must take a while? It can. In extreme cases, like legacy system integrations or highly customized solutions, completing the software integration testing cycle may take a few months.

Yet, something we’ve noticed while working with our clients is that product complexity doesn’t determine testing duration. Well, it does to a degree. But not as much as you’d expect.

There are many integration testing strategies in software testing. And the best approach is productive prioritization.

1. You focus on critical elements first to secure a functional base.
2. Branch out from there for ampler coverage.
3. And, depending on your resources, check everything else at your pace.

Here are a few examples of integration scenarios you should consider earlier.

• Verify the integration of data from multiple sources or systems.
• Test the integration between various components’ error-handling mechanisms.
• Validate the integration between modules under diverse load conditions.
• Check the integration between security controls and the application.
• Review the integration of the software with different OSs, browsers, devices, and versions.
• Examine the integration between batch processing jobs and real-time processing components.
• Inspect the integration between different interfaces (e.g., command-line, graphical, application programming).
• Test the integration between components that communicate asynchronously (e.g., via message queues or event-driven architecture).
• Verify the integration between different steps or stages of complex business workflows.
• Assess the integration between components developed by different teams or departments.

For a more streamlined process, you could explore iterative approaches. Continuous integration and testing are aimed at speeding up SDLCs and reducing expenses. Plus, they’ll encourage closer dev-QA collaboration, enhancing product quality.

Automated Integration Testing Is a Big Yes

Another option for efficient integrations is automation. Well, it’s probably the first thing you thought about. And you’re right to do so.

Automated testing services can be a much-needed boost (or a necessity).

• They significantly reduce the time and effort required to execute test cases.
• The teams can zero in on critical tasks.
• You can achieve faster feedback loops and accelerate delivery.
• Automation ensures consistency and repeatability in test execution.
• It eliminates human errors and increases the reliability of test results.
• You can detect integration issues much faster.
• And automated regression lets you quickly verify code changes.

But, at the same time, keep in mind there’s something we like to call “automation dupe”. Since automation testing (AT) offers so many perks, you might want to apply it to as many aspects as possible. Yet, don’t forget that AT always comes with a few catches:

• It requires an initial investment of time, resources, and expertise (often quite a big one).
• AT needs ongoing maintenance to keep pace with changes in the software.
• Complexity in the test environment setup can impede efficiency.
• Inadequate automation services can compromise product quality.

The point is – AT is always a good idea. But you need to figure out why you need it (precise strategy) and what for exactly (coverage). Also, strive to always supplement automation with manual testing services. Relying solely on automated integration testing may create a false sense of security.

So, automate smartly and use manual and exploratory tests to uncover hidden issues and ensure thorough validation. You can start small to see whether AT is the right choice for you. For example, begins with automating:

• Critical integration points.
• Frequently executed scenarios.
• Regression tests.
• Boundary and edge cases.
• API and external integrations.

After that, it’ll be easier to determine if automation works for you. And you can create a backed-up roadmap for how you’d want to proceed.

The Challenges of Creating Automated Test Scripts (And Ways to Overcome Them)

How To Do Integration Testing the Right Way

No amount of fancy integration testing strategies in software testing can beat this one. We’ve found it to be the most capable for achieving our clients’ goals. Sure, you can tailor the details to your teams’ knowledge and product specifics. But take our word for it – this is the basis you can’t miss out on.

#1 Study Your Software

Before beginning integration testing, thoroughly understand your software’s:

• Architecture.
• Components.
• And dependencies.

You’ll be able to identify critical integration points and plan effective testing strategies.

#2 Prepare a Plan with Timelines & Scope

Develop a detailed plan outlining the scope of integration testing, including:

• Modules to be tested.
• Timelines for testing activities.
• Resources required.

Clearly define the objectives and expected outcomes of the testing process. It’ll help you stay organized and better manage your resources.

#3 Outline Relevant Use & Test Cases

Identify relevant use cases that represent typical user interactions with the software. Make sure they cover various scenarios:

• Standard (or ideal flows).
• Boundary cases.
• And error conditions.

This approach lets you focus on the customer. And that’s something we encourage everyone to do. It’s the only way to superior UX.

#4 Test & Report Bugs

Document any bugs or issues encountered during testing. And do it carefully. Always provide:

• Detailed descriptions.
• Steps to reproduce.
• And expected vs. actual results.

Comprehensive explanations make sure that QA specialists and developers understand what’s going on. So they’ll be able to deal with bugs faster.

#5 Retest After the Fixes

After amendments, never skip on retesting the affected areas. This way, you verify that the fixes have been successfully implemented and that no new issues have been introduced.

#6 Run Regression Testing

Perform regression testing to guarantee that existing functionality hasn’t been affected by modifications or updates. Re-executing relevant integration tests helps keep the system up and running. You can also see how your QA strategy is working so far.

#7 Add Automated Integration Testing

Integrate automated testing to improve efficiency and reliability. Here, it’s important to select AT tools and frameworks that cover your needs and suit present workflows. Plus, don’t forget to continuously update and expand the AT suite to handle new scenarios.

Exploring the Journey to Smart Test Automation

Best Practices for Software Integration Testing

Now, it’s time for some expert insights. This list is based on our QA specialists’ feedback on how companies can refine their software integration testing. So, save it for later and revamp your integration tests.

1. Begin integration testing early to identify and address issues proactively.
2. Study your software’s architecture and identify critical components. Prioritize testing efforts in these areas to ensure robust integration.
3. Pay special attention to testing data interactions, compatibility with external systems, and adherence to APIs to ensure smooth integration.
4. Regularly maintain and update your integration test suite to accommodate changes.
5. Separate integration testing from business logic testing to isolate and focus on integration-specific issues.
6. Foster collaboration between testers and developers throughout the integration testing process.
7. Maintain comprehensive records of test results to track progress and facilitate teamwork.

Integration & Testing Tools in Software Engineering

And, of course, we can’t forget about integration testing tools. We’ve touched on the subject before. But here, let’s discuss how you can select proper “helpers” for your project.

Pick tools and software based on your product needs exclusively. You might feel tempted to go for options that are critically acclaimed, so to speak. But only you know what your project requires. You don’t want to spend money on resources that are “really good” but don’t cover your demands.

Don’t feel weird about combining a few tools. It’s hard to select an option that fits your testing purposes like a glove. You can mix and match various alternatives (even free ones).

Be sure not to overwhelm your team with legions of tools. Blending a few options is fine. But don’t approach this as “this one is for this”, “that one is for that”, “and the other one is for something else”.

Focus on software that developers and QA engineers don’t have to learn from scratch. You’ll spend more time on them figuring out how to use the tools rather than actually testing. Always go for tools familiar to your crews. Yet, if you can’t do without an unknown option, make sure to allocate adequate time and resources for training.

Now, here’re a few tools to get you started.

Tessy

Tessy is a tool primarily used for automated unit and integration testing of embedded software written in C or C++. It supports:

• Test case generation.
• Text execution.
• Code coverage analysis.

And it’s overall ideal for teams working on embedded systems.

Citrus Framework

The Citrus Framework is an open-source Java-based integration testing framework. It’s designed for testing messaging and integration layers in enterprise applications. This tool supports various communication protocols and message formats, such as:

• HTTP.
• JMS.
• SOAP.
• And REST.

With Citrus, you can simulate messaging scenarios, send and receive messages, and validate message content and structure.

FitNesse

FitNesse is a collaboration and acceptance testing framework. And it’s open-source, too. You can create and execute acceptance tests using its wiki-based interface.

The software lets you write and run tests in a plain-text format, easily understandable by non-technical users. This way, it promotes collaboration between:

• Developers.
• QA experts.
• And stakeholders.

Also, FitNesse supports automated integration by facilitating acceptance test creation.

To Sum Up

The IT space has seen many revolutions recently. New methodologies, principles, technology… It’s rather inspiring, actually. But it made companies focus on the new, shiny stuff, leaving out the fundamentals.

You should never forget about the backbone of productive testing – the seemingly basic tests you haven’t thought of in a while. After all, they are the core of your product. So, show integration testing some love. And work with capable QA providers who give them what they deserve.