Are you aiming to provide the best end-user app experience to your audience? Then, you cannot avoid integrating comprehensive software testing. Among all the options available in the market, JUnit testing stands out as the most popular for testing Java apps. This is because it provides a simple and effective way of writing the unit test cases.
With JUnit testing, the testers can also ensure the quality and reliability of the overall testing code. However, we would warn the testers that writing effective and efficient JUnit test cases requires strict compliance with certain best practices.
So, with this article, we will help the testers find out the best practices for JUnit testing. These practices are directly responsible for enhancing the testing efficiency and also ensuring the robustness of the overall code base.
Learning About JUnit
To give a formal introduction to JUnit, we can say that it is a well-known testing framework for Java apps. This is mainly designed to simplify the process of writing and executing the unit testing instances.
While running the testing process, the testers often separate multiple elements present on the app into smaller components. These components are often referred to as units. So, unit testing is the process of verifying the proper functioning and placement of all these individual components.
Using this testing process, the testers can divert their focus toward individual units of software and run the test cases in an isolated environment. The final goal of this process is to verify that each unit functions correctly as intended during the test planning process.
While creating the test cases with JUnit, the developers can natively access various assertions, annotations, and other utilities. These inclusions facilitate the writing and execution of test scripts. Let us formally introduce all these utilities available with JUnit testing:
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Annotations
JUnit takes the help of annotations to mark methods as setup methods, test cases, and tear-down methods. The list of annotations will include ‘@Test,’ ‘@Before,’ ‘@After,’ and ‘@BeforeClass.’ You will commonly use all these annotations for defining the test structure.
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Assertions
JUnit also has a huge set of assertions aimed for verifying the expected behavior of the code that is currently being tested. The list of assertions has options like ‘assertEquals,’ ‘assetTrue,’ ‘assertFalse,’ and many others. As app testers you can use these assertions to easily track reports and condition failures. These errors might be present in the app infrastructure.
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Test Runners
JUnit also has dedicated test runners that help the developers to actually run the test instances. Based on the testing requirements, it has different test runners for running the test scripts on different environments like “Parameterized,” “BlockJUnit4ClassRunner,” and many others.
Best Practices for JUnit Testing
While executing JUnit testing, there are various factors that the testers must be aware of to ensure that they are using the full potential of their testing infrastructure. However, to dial down this knowledge for the newcomers in the segment, we mentioned the most important ones in this list:
1. Write Small and Focusses Tests
To begin with, the testers must ensure that each testing method mainly focuses on testing a single unit or behavior of the app code. To implement this process, the testers must keep the test cases small and targeted. This will also help them to ensure the tests remain maintainable and comprehensive in the long run.
The testers should also consider the fact that small test cases are easier to debug and maintain. Finally, these test cases will also provide more focused feedback when they fail. Thus, the testers can perform targeted troubleshooting processes to ensure timely deployment of the app.
We have mentioned a sample code snippet that will help the developers understand the concept of creating small test cases:
2. Use Descriptive Methods and Variable Names
Next, the testers must focus on creating clear and descriptive methods and variable names. This inclusion will make the test cases more readable and understandable. It is also worth mentioning that a well-named test method should convey the expected behavior that is being tested with it.
Finally, by adopting simple nomenclature, the testers can ensure that even the non-technical members of the team can understand the basic purpose of these test instances.
We have mentioned a sample code snippet that can help further understand the objective of this point:
3. Use Setup and Teardown Methods Appropriately
As we already mentioned, JUnit provides ‘@Before’ and ‘@After’ annotations for setting up and tearing down the resources required for executing the test cases. So, the testers can intelligently use these methods for initializing common objects or resources which will be required for multiple testing methods.
The proper implementation of these annotations will also drastically reduce the app’s complexity to improve the overall readability of the test cycle.
The following code snippet will allow the testers to understand the implementation of these annotations as per the testing requirements:
4. Use Parameterized Tests
By using parameterized test cases, the testers can run the same test script with different inputs. This is a very important parameter to massively reduce the code duplication process and also make the test cases more concise and maintainable.
Parameterized test cases also ensure that the testers do not have to write the entire script for every individual component or unit. Various experts believe that the proper implementation of parameterized test cases can allow the testers to reuse almost 60% of the existing test code.
The following code snippet elaborates the process of implementing parameterized test cases with JUnit:
5. Use Assertions Judiciously
Although the assertions and annotations available with JUnit are very popular and can massively influence the overall outcome of the testing process, the testers must choose appropriate utilities which accurately verify the behavior of the code.
Moreover, it is also important to avoid using multiple assertions within the single test method. This is because it can make the test case complex and harder to understand. This process will also hamper diagnosing the test cases when they fail.
So, we advise the testers to aim for one logical assertion per test method while executing JUnit testing. To further elaborate on this process, we have mentioned a sample code snippet in this regard:
6. Implement Test Exception Handling
While executing JUnit testing, the testers should also ensure that the code handles exceptions correctly. You can perform this process by testing scenarios where exceptions are expected to be generated. In these cases, the testers should use the ‘@Test’ annotation’s ‘expected’ attribute or ‘assertThrows’ method.
This implementation will help the testers to ensure that the expected exceptions are thrown during the execution process. It will also help ensure that the app is ready to handle various real-world use cases and unexpected errors.
To further help with this information, we have mentioned a sample code snippet for achieving this goal:
7. Mock the External Test Dependencies
While executing JUnit testing, the testers will have to handle various classes, which will depend on external resources or services. In these cases, the testers can consider the prospect of integrating mocking frameworks like Mockito. It will help simulate these dependencies without the physical integration.
The advantage of this process is that it isolates the unit that is being currently tested and makes the testing process faster and more reliable. Using the code snippet that we have mentioned below, the testers can mock external dependencies with JUnit testing:
8. Use Cloud Testing
Using AI-powered test orchestration and execution platforms like LambdaTest, the testers can integrate JUnit testing with automation frameworks like Appium or the Selenium WebDriver. This integration will allow the app testers to automatically execute the test instances as per their requirements.
LambdaTest can also execute the JUnit test cases on more than 3000 different combinations of devices, operating systems, and browser versions. Since it is an AI-based test orchestration platform, the testers can use artificial intelligence and machine learning to better organize the test instances.
This platform also provides access to outdated browser versions and very old devices to further improve the app compatibility. Some of the additional features of this platform include comprehensive test report generation, native bug tracking capabilities, and live test activity logging.
9. Run the Test Cases Frequently
We advise the testers to make it a habit to run the test cases frequently. The most ideal approach in this regard is to run it after every small code change. This approach will help the testers catch issues at the earlier phases of the development cycle. It will also help reduce the time and effort which will be required for debugging and fixing the errors at the later phases of the development cycle.
Using this implementation, the testers can also ensure that they remove errors from Java test cases before they can directly hamper the app’s functioning.
10. Implement Continuous Integration
We also advise the testers to consider the idea of adding JUnit test cases into a continuous integration pipeline. This addition will help automate the testing processes and streamline the overall development cycle. There are various tools like Travis CI, GitHub actions, or Jenkins that can help perform this goal.
It also helps the testers to run tests automatically whenever the system detects any change to the code base. The final implementation of this process ensures that new code doesn’t break the functioning of the existing code within the application interface.
11. Refactor the Tests Regularly
Finally, with the evolution of the code base, the testers must refactor the test scripts to keep them aligned and maintainable with the current implementation. It is very important to ensure that the test script has all the required code to verify the functioning of all the new elements that have been integrated within the app infrastructure.
During the refactoring process, the testers must also ensure removing redundant test scripts, updating the outdated test instances, and improving the overall test coverage whenever necessary. This process also has a direct impact on ensuring that the app companies can smoothly roll out future updates to the interface.
The Conclusion
Focusing on all the arguments discussed in this article, we can summarize that writing efficient and effective JUnit tests is crucial for ensuring the reliability and quality of your Java apps. So, by following the above best practices, testers can enhance the testing efficiency and also lower the maintenance overhead. This process also helps the testers to build a robust test suite which provides confidence in the overall code base.
As modern testers we must remember that investing time in writing good test cases at the initial stages will massively help to save a lot of time and effort in the long run.
