Integration Testing: What, Why, Types, Best Practices, and Examples

When you integrate the different components of your application, you need to test them via integration testing. This guide discusses the various aspects of it, including the what, why, types, and best practices, with added examples for better understanding.

Ah! Integration testing! It is like the last boss of software development to defeat. When you think your code is errorless, integration testing gets you off your high horse. But do not trouble; it is not all death and darkness. Integration testing is an essential step in making sure that all the different parts of your software work together without breaks, like a thorough being without error put into an arts-based order dance troupe.

This guide runs you from pole to pole about integration tests, what it is, why to use them, and best practices alongside examples to ensure all you need to know!

What is Integration Testing?

Integration testing is the process of testing how different modules or components of your software work together. Well, you don’t want your software to crash and burn when real people use it, do you? Several integration tests exist, such as top-down, bottom-up, and bi-directional. Each sort has its forces and feeblenesses, and your selected sort will depend on your unique needs, ends, and purposes.

Of course, there are also best practices to follow regarding integration tests. So, whether you’re a software developer or just someone interested in the inner workings of technology, integration testing is something worth knowing about. And who knows, maybe you’ll be the one doing the testing!

Why Integration Testing?

Why Integration Testing, you ask? The key objective of this testing is to ensure that all the different parts of your software work together seamlessly. Think of it as a way to test the communication skills of your software components – if they can`t talk to each other properly, then your software won’t work as it should. The primary goal is to catch any bugs or issues arising from combining modules.

By thoroughly testing how all the different components work together, you can provide a seamless experience for your users. Identifying and fixing any issues arising during testing for integration can provide your users with a reliable and seamless experience. And who doesn’t want happy users?

Here are some key reasons why integration testing is important,

  • This testing is essential to make sure that individual software modules, created by different developers with different understandings and programming logic, function together seamlessly.
  • This testing is needed when client requirements change during module development, as these new aspects might not have been individually tested.
  • To identify the bugs that may arise in the interactions between software modules and the database.
  • To discover potential issues that might occur in external hardware interfaces.
  • To mitigate problems caused by insufficient exception handling.

Who is responsible for integration testing?

Integration testing is mainly performed by developers after the individual modules are tested and integrated together into a single codebase. That is, it is performed after the unit testing and before the system testing. 

In some cases, organizations may have dedicated quality assurance (QA) teams where they collaborate with developers to perform this testing as part of a broader testing strategy.

You can automate integration testing using a low-code test automation platform like Testsigma to accelerate your testing process and make it more efficient.

Key Objective of Integration Testing:

  • Improve software quality: This testing helps improve your software’s overall quality. This leads to a higher quality product that meets the needs of your users.
  • Reduce development time and cost: Integration tests can help to reduce development time and cost by catching issues early in the development process.

Should Integration Testing be Automated?

For starters, automated integration testing may drastically save testing time and effort. This is because automated testing can perform numerous test cases fast, which would be impossible to accomplish manually.

Human mistakes or inconsistencies that may arise during manual testing are not present in automated tests. Lastly, automated testing can aid in identifying errors and difficulties early in the development process, saving time and money. Plus, sitting back and watching the computer do the heavy lifting is always more fun.

Apart from the benefits, automated testing is useful when you need to run a particular test case frequently. For example, when software is often updated or changed, it is critical to do tests frequently to guarantee that changes don’t disrupt actual functioning.

Additionally, manual testing can be time-consuming and challenging due to the many dependencies and interfaces.

Testsigma is an effective automated integration testing tool. It provides extensive test automation capabilities for web, mobile, desktop, and APIs from a unified platform, making it perfect for complex software applications. It is also open-source platform that allows for the customization of tests to meet unique requirements. It’s intuitive design and seamless interaction with other tools assist teams in identifying and correcting mistakes early in the development cycle, saving time and money. Get here – List of open source automation testing tools.

Integration Testing Techniques/Types

Below are some of the most common techniques:

Top-down testing:

It’s an iterative strategy that connects two or more logically linked components. This approach aims to identify any integration issues that may arise as the different components are combined. It begins with testing the largest or main component of an application. Testsigma can be utilized to test a complicated online site by starting with the main webpage and progressing through the other components in decreasing priority order.

Bottom-up testing:

In this testing, integrated code modules are tested before evaluating the entire system or code base. It begins with testing the smallest components of an application. Testing a payment gateway from the lowest to the highest-level components using Testsigma is an example of a bottom-up testing scenario. Read the Difference between top Down and Bottum Up Integration testing.

Big-bang testing:

All the components are interlinked as a single system and is tested as a complete system; testing a system with all units linked together is difficult due to the lack of attention paid to checking the interfaces between separate units. This approach helps identify issues when integrating all the different components. A big-bang testing scenario using Testsigma can involve evaluating a new e-commerce website with a shopping cart, payment gateway, user registration, and order management elements.

Sandwich testing:

This technique involves testing the integrated components in pairs. This approach aims to identify any issues that may arise when specific features are combined. Testing a booking system by pairing the front-end and back-end components to guarantee proper communication is an example of a sandwich testing scenario using Testsigma.

Automated integration testing in software testing can help ensure software components work correctly and can be done more efficiently and successfully with a unified testing platform like Testsigma.

Testsigma is also available as an open-source and free version.

How to Do Integration Testing?

Integration tests are critical in software development, ensuring all application components perform correctly. To make things easier:

  • Create an integration test plan for testing the integration of components – Follow a strategy to test according to the testing types mentioned above.
  • The test plan should include test cases with priority and expectations.
  • Assign the test cases for execution.
  • Execute the test cases
  • Record the results of test cases.
  • Report the failures.
  • Once the failures are fixed, verify the fixes.
Integration testing

Brief Description of Integration Test Plans

This testing encompasses the following attributes,

  1. Testing methods/approaches.
  2. Scope/out-of-scope items.
  3. Tester roles and responsibilities.
  4. Pre-requisites, if any.
  5. Test environment for testing purposes.
  6. Strategies for risk identification and mitigation.

How to Automate Integration Testing?

  • Choose an Automation Tool: The first step is to choose the right tool for test automation. You should opt for a tool that works for your use case and is easy for your team to use. Also, you should ensure that the tool will provide you ROI within some stipulated time. Here, you can opt for end-to-end testing solution like Testsigma, Selenium, or Appium.
  • Create Test Scripts: When you’ve decided on an automation tool, write test scripts to replicate the integration of the software components. These scripts should contain test data, actions to be taken, expected outcomes, and reports to analyze the components post-test.
  • Run Test Scripts: After the test scripts are in place, use the automation tool to run them. This will assist in discovering any flaws as soon as possible.
  • Analyze Results: Analyze the results after executing the test scripts to find any identified problems or flaws. Repair the problems and repeat the testing until all components are properly integrated.

Entry and Exit Criteria of Integration Testing

The entry and exit criteria help define when to start and stop the testing process. Below are some of the entry and exit criteria for integration testing,

Entry Criteria

  • All individual units/software modules must have undergone successful unit testing.
  • All high-priority issues must be fixed.
  • The modules should be completed and integrated successfully into a single codebase.
  • The test plan should be prepared and reviewed, including test cases and scripts.
  • The test environment, including hardware, software, and network configurations, should be set up and ready for testing.

Exit Criteria

  • All the integration test cases must be executed.
  • The test documentation should be updated, including test results and any changes made during testing.
  • Any bugs identified during this testing should be logged, tracked, and resolved.
  • An exit report summarizing the results of the testing phase should be prepared and shared with relevant stakeholders.

Tools for Automating Integration Test

Regarding automating integration testing, several great tools can help streamline the process and save you time and effort. Let me give you a quick rundown of some of the most popular options:

  • Testsigma: Testsigma is a no-code test automation platform that enables users to construct straightforward English tests, and does not require you to learn to code. It can be used to automate your tests for desktop, mobile, API, and web applications.
    Testsigma is a great asset for any software development team because of its straightforward design and powerful features, which allow for a seamless testing experience while interacting with other tools and continuous testing. Testsigma can assist in streamlining testing efforts and identifying any flaws early in the development cycle, thanks to its user-friendly interface and extensive capabilities.
  • Selenium: The most important idea is that this tool is widely used for automated testing, as it is free and open source, supports multiple programming languages, and can test web browsers across various browsers and platforms.
  • TestComplete: TestComplete is a premium product with cutting-edge features like cross-browser testing, reusable test scripts, and desktop and mobile app testing; the steep learning curve may not be suited for people without a lot of testing expertise.

Here, get the best Integration Testing Tools List.

Of all these options, I’d highly recommend trying Testsigma. Testsigma is an easy-to-use tool for creating reliable and efficient tests, 5x faster. When you go for the Testsigma cloud, you don’t need to bother about infrastructure maintenance too.

So why not try and see how it simplifies your test automation process?

Advantages of Integration Testing

This testing offers several advantages regarding ensuring your system’s overall quality and functionality. Here are a few key benefits:

  • Early detection of issues: This testing can help detect problems early in development, making them easier to resolve and less expensive.
  • Improved quality: By discovering flaws before they become production issues, tests may help assure a higher quality system.
  • Better collaboration: This testing necessitates collaboration and good team communication, improving cooperation and a more coherent output.
  • More efficient testing: Automated integration tests may save time and effort by executing tests more quickly and reliably.

Introducing automation into your testing process may further enhance these benefits. Automated tests can be conducted more rapidly and consistently than manual tests, and they can assist in detecting flaws that manual testing cannot.

Challenges of Integration Testing

While this testing has numerous advantages, it may also be difficult and time-consuming. These are a few common stumbling blocks to be aware of:

  • Complexity: The test examines how various system parts work together, which may be challenging and time-consuming.
  • Dependencies: Components in a system may depend on other components or external systems, making it difficult to pinpoint and test problems if you manually incorporate them while writing tests.
  • Maintenance: As the testing requirements evolve, integrating testing with new components might become difficult.
  • Cost: Because of manual testing, developing and performing tests can be expensive.

Best Practices for Integration Testing

Following a few best practices is essential to get the most out while testing for integration. Here are a few tips to keep in mind:

  • Plan: Determine what and how you’ll test to guarantee you’re testing the proper items and avoiding delays.
  • Start early: Don’t put off testing till the conclusion of the development process. Begin testing as soon as possible to uncover problems before they become more challenging and expensive.
  • Use real test data: To detect flaws that may not be seen with manufactured or simplified data, test data should be realistic and indicative of the data your system would encounter in the actual world.
  • Use automation: Automation can make integration tests more practical and economical. It can be conducted faster and more reliably than human tests and can help identify problems that manual testing cannot.
  • Define clear objectives and expectations for integration testing. Understand what needs to be tested, the scope of the integration, and the desired outcomes.
  • Test environment: Create a test environment that closely mimics the production environment.
  • Regularly run integration tests: especially when changes are made to components or modules, to ensure new updates do not break existing integrations.

By following these best practices and incorporating automation into your integration testing process, you can help ensure that your system is of the highest quality and functionality possible.

Example of Integration Test Case

An integration testing example test scenario may be as follows:

Some examples of integration test cases might look like :

Test Case IDTest DescriptionInputExpected Result
TS-1Test integration between the payment gateway and the booking systemUser books a service and makes a paymentPayment is processed correctly and the booking is confirmed
TS-2 Test the integration between the messaging system and the notification systemUser sends a message and receives a notificationThe message is delivered correctly and the user receives the expected notification
TS-3Test the integration between the billing system and the accounting systemSystem generates a bill and sends it to the accounting systemThe bill is correctly processed and recorded in the accounting system
TS-4 Test the integration between the search engine and the recommendation engineUser performs a search and receives recommendationsThe search results and recommendations are accurate and relevant to the users search query


Knowing what integration testing is, why it is necessary, and how to approach it would improve your overall tests.   One major takeaway is the use of automation in the tests, which may assist in guaranteeing that this testing is done swiftly, precisely, and thoroughly. Furthermore, a disciplined and systematic approach to the tests is required to guarantee that systems function properly and provide users with the desired value. This post should help you approach the test more confidently and effectively.

Frequently Asked Questions