Whether you’re preparing for a test automation job interview or you want to learn more about the types of testing, this post gives you an overview of the different kinds of automation testing that exist.
Why do we want to know different types of automation testing?
Each type of testing has its own specific goals. Some testing types are more important than others. Knowing what types of automation testing exist will help you to determine which tests are critical to guarantee the quality of your code.
Let’s explore the first automation testing type.
#1: What Is Unit Testing?
Unit testing is concerned with testing atomic chunks of code. Unit testing mostly focuses on just one function definition. Often, stubs are used to block any I/O operations like writing to a database or API calls. This allows the testing engineer to only test the logic contained by the function.
Example of Unit Testing
For example, we have a function with different if statements that all hold an expression. In order to test the validity of each if statement and its expression, we use unit testing to verify the validity of the logic.
Benefits of Unit Testing
Unit testing allows verifying the logic of the code. Therefore, this type of testing increases confidence in the code. It allows a developer to quickly identify bugs in the logic they wrote. Also, unit testing is one of the easiest types of tests to write. Added to that, when a certain test fails, debugging is relatively easy.
#2: What Is Integration Testing?
A testing engineer uses integration testing to verify the integration between different units of code. An integration test should expose faults whenever two components of code don’t work together. Often, faults against the interfaces of components are found.
One of the most common approaches toward integration testing is top-down testing. This means that the most top-level components of code are tested for their integration. Whenever the top-level components integrate nicely, we can be sure that the lower components also work as expected. We can make this assumption as the top-level components use the lower-level components.
Other testing approaches include the below:
- Big bang: Combines all unit tests and runs them as integration tests.
- Bottom-up: Opposite of the top-down approach. Starts with testing the integration between the lower components before moving up.
- Sandwich, or hybrid: Combination of top-down and bottom-up testing. It ensures a higher quality of code but takes more time to write.
Let’s take a look at a possible scenario for integration testing.
Example of Integration Testing
Assume we want to test a simple flow for an email service provider. The testing engineer wants to verify if a user can log in, send an email, and log out again. We can verify the correct behavior of each step with unit tests. However, when we want to verify the whole flow at once, we need to write integration tests.
Benefits of Integration Testing
In short, integration testing helps to increase confidence in the code. It helps the testing engineer to verify real use cases a user might go through. Also, integration testing helps the team to find wrong interfaces, broken connections, or integration mistakes.
Next up, let’s find out about regression testing.
#3: What Is Regression Testing?
Why do we need regression testing? Regression testing is a great approach to make sure the quality and performance of the code remain the same. Regression tests are run every time a new feature is added, code changes, or code gets deleted.
Examples of Regression Testing
A common regression test is old fix regression testing. This means that you retest several old bugs that were fixed before to see if they pop up again.
Another example of regression testing is configuration testing. For example, a new version of an operating system gets released. Configuration testing will check that the performance and usability of the application aren’t affected by this new version.
How to Choose Test Cases for Regression Testing
As regression testing often involves intensive testing, the cost can be high. Make sure to re-execute only the necessary tests related to a new code change.
Besides that, define a development plan as regression tests are timely. The development plan should bundle bugs or list features after which they want to run regression tests. This helps to reduce the overall cost of regression testing.
Added to that, Capgemini states that you should only run regression tests for the following cases:
- Configuration changes
- Emergency fixes for the production environment
- Major release being deployed
- New features being completed
Benefits of Regression Testing
Regression testing aims to find bugs for new code changes or features. It helps to ensure that the system behaves in the same way after these code changes have been introduced.
Now that we’ve covered regression testing, let’s find out more about smoke testing.
#4: What Is Smoke Testing?
The next testing type is smoke testing. Smoke testing is an important aspect to verify if a build is stable. A testing engineer executes smoke tests as part of the quality assurance (QA) life cycle. The QA team has to determine if the build is stable. If so, the development team can continue with developing a new feature.
Example of Smoke Testing
Smoke testing consists of a small set of tests that help to verify the stability of the application. An example of a simple test includes logging in to the application with a valid username and password. This case might seem simple but helps to verify the basic functionality of the application.
How to Do Smoke Testing
Smoke testing can be automated or performed manually. Often, a testing engineer prefers to manually verify if the functionality works as expected.
Preferably, the testing engineer defines one or multiple critical paths throughout the application. A critical path refers to an important flow of operations the testing engineer verifies to determine the stability of the application.
However, some organizations prefer to automate this step. As we’re speaking about a small set of simple tests that verify critical behavior, these can be manually tested as well. In the end, the user will execute these steps manually when using the software. By manually testing the application, the testing engineer can spot slow operations, UI items that aren’t perfect, or any other bug that’s hard to detect by an automated tool.
If smoke testing fails, it’s obvious that the code is sent back to the development team. Next, the development team should fix the defects as quickly as possible.
Benefits of Smoke Testing
Let’s briefly list the advantages of smoke testing:
- Is easy to perform
- Finds critical defects earlier in the software development life cycle
- Minimizes integration risks
- Guarantees the core functionality works as expected
Lastly, let’s find out about functional testing.
#5: What Is Functional Testing?
Functional testing is a way of testing that helps to verify the requirements for a feature. It simply takes an input and verifies if the output matches the expected output. Generally, the test doesn’t care about the actual source code. Some say it’s a form of black-box testing where the tester doesn’t know anything about the source code.
Examples of Functional Testing
Some examples of functional testing include the following:
- Verification of user interfaces
- Checking an API response
- Checking the state of a database
Benefits of Functional Testing
Functional testing allows the testing engineer to check the main functions of an application. Also, functional testing helps to verify error conditions and if they throw an appropriate error message.
In short, functional testing ensures that all requirements are met. Often, the client will perform functional testing to make sure the application behaves as they wish. By regularly performing functional tests, we can check the requirements early on in the software development life cycle. This reduces the risk associated with the product or software.
Do Other Types of Testing Exist?
Yes, many more types of testing exist. Some other types include acceptance testing, interface testing, or sanity testing. However, you can guarantee a good level of quality by implementing unit, integration, functional, and regression tests.
In my opinion, smoke testing is not a must-have. Smoke testing only verifies the core behavior of the product or service. The combination of the other four testing types should give a much better image of the stability of your product. Nonetheless, it’s always nice to have an idea about the stability of a software build.
In conclusion, this post should help you to determine which tests are vital for your project and why you should implement them. Each testing type has a specific goal, and it’s important to know when to use which testing type. If you want to learn more about other testing types you can implement in your project, it’s worth reading this testing piece on DZone.
Author bio: This post was written by Michiel Mulders. Michiel is a passionate blockchain developer who loves writing technical content. Besides that, he loves learning about marketing, UX psychology, and entrepreneurship. When he’s not writing, he’s probably enjoying a Belgian beer!