An Overview of JUnit: the Best Java Testing Framework
Tags: java, testing
Published: 2022-09-28 13:51:47

**Introduction**

JUnit combines two popular terms – Java and Unit Testing. Let us first look into these terms independently.

Unit testing is a software development course in which the lowest testable neck of an application, known as units, are independently and individually inspected for proper working. This testing approach is served during the development procedure by the software developers and, occasionally, the QA staff. The most crucial intent of unit testing is to seclude scribbled code to test and decide if it works as intended. Unit testing is a significant step in the development procedure because if it is done rightly, it can help discover early glitches in code, which may be tougher to detect in later testing phases. Unit testing is a building block of test-driven development( TDD), a realistic methodology that takes a diligent path to fabricate a product through continuous testing and reviewing. This testing methodology is also the first degree of software testing; it is accomplished before other software testing techniques like integration testing. Unit testing is generally included to assure a unit does not count on any external functions or code. In this article, we will be discussing JUnit, an online Java-based framework in which Unit Testing is performed by exploiting the programming language of Java.

**What is JUnit?**

With the increasing popularity of Java in software applications, JUnit has also gathered some serious fame and popularity.

For many years, JUnit has been helping in the development course of a test-driven approach for Unit Testing of several apps. Through JUnit, developers can conduct unit testing on every software element before it goes to testers or the QA team. Tests are run very quickly. The GUI available in JUnit for writing manageable and reproducible test cases makes it stand out above other testing architectures on the internet. The failed test cases are listed in a separate section for easy debugging.

Apart from manual testing, JUnit is preferred identically for automation testing. It can also work with the Selenium WebDriver for web application test automation. Automated testing with JUnit provides a unique way to write short, structured, and better test cases. It uses annotations to authorize the creation of various test scripts, applying several strategies for multiple purposes.

**The requirement for JUnit Testing**

The most pivotal reasons for taking up Automated testing with JUnit are as follows:

- It is used for finding out bugs beforehand during the development stage. It increases the reliability of the code.
- The architecture lets the developer spend more time reading the code than writing it.
- It makes the code more reliable, readable, and free of errors and bugs.
- It motivates the developer immensely by boosting their conviction.

**The importance of the JUnit Testing Framework**

While JUnit is a rudimentary way to test Java-based designs and projects, it provides numerous benefits. Some of the advantages of employing the [JUnit Testing Framework](https://www.headspin.io/blog/junit-a-complete-guide) are as follows:

- **Open-Source:** JUnit is an open-source framework used for Unit Testing. Therefore, a broad community of QA teams can contribute to the software, leading to quicker and better development from developers around the globe.
- **Early bug-finder:** The JUnit testing framework finds the bug beforehand in code compared to other testing infrastructures. When a glitch or bug is found, a separate section indicates them unless it is resolved. It helps in driving the focus on debugging.
- **Best for Test-Driven Development( TDD) Environment:** Numerous engineering squads pick up a test-driven development cycle for pushing the minimum number of bugs to QA squads. Tests are performed by the developers first. Then the glitches are resolved. Then the frame is forwarded for QA testing. Assertions are used in the Junit tests, and it is most effective when they fail. Hence, JUnit aids in the Test-Driven Development constitution of the software.
- **Easily interpretable results:** The test results of the JUnit testing framework are represented by showing the test progress in a bar. It makes them easily interpretable.

**Features of JUnit**

JUnit consists of several features that increased its popularity. Some of them are as follows:

- **Open-source:** JUnit is an open-source network for Unit testing. It allows developers to write codes with better grades and much quicker.
- **Provides Annotations:** It provides numerous annotations for the identification of test methodologies.
- **Provides Assertions:** Some assertions are used to test anticipated results.
- **Provides Test Runners:** JUnit provides test runners for running tests.
- **Improves code quality:** JUnit has gained very high popularity for testing effectively. It enables quicker code writing, which results in a proliferation in the code's quality.
- **Automated tests:** These test results do not need an automatic checking operation. All the tests automatically run on JUnit, and the marks acquired are again checked automatically. Also, it provides feedback.

**Getting Started with Automation Testing by applying JUnit**

Software testing Automation refers to the course of testing the software using some automated operations. Automated software testing drops human intervention and increases the success rate and accuracy of the tests. A dedicated tool or platform is used for reproducing the user's actions and reiterating the test cases.
JUnit testing framework is one of the best platforms for creating reiterated test cases. However, one does not require to write it numerous times or not even execute it multiple times manually. If there is a need for conducting a test in JUnit many times, the operation is fully automated. Automation testing is generally preferred over manual testing due to its rapid and trustworthy sequences. Since the margin of error is veritably less in automation testing, speaking about JUnit without considering automated software testing will not be enough.

The fundamentals that make up the website work as the manufacturer wants. Tests are conducted on different web browsers to identify any glitch and optimize the website or the code because each web browser is distinct and renders the website differently. Automation testing with JUnit by applying Selenium has become a popular approach in real-user conditions. For this, QA brigades are nowadays embracing cloud-based online software testing platforms. QA teams can run Selenium test suites on a real-device cloud of numerous real devices and web browsers on these platforms. 

**Selenium Testing with Junit framework**

Testers can use annotations and assertions to make the course of testing with JUnit more reliable and robust. Let us get acquainted with some of the annotations and reports used in JUnit for Automated testing.

**Annotations used in JUnit Testing**

JUnit [automated testing framework](https://www.headspin.io/blog/what-are-the-different-types-of-test-automation-frameworks) consists of several annotations and assertions administered in the code during the testing. These are the pointers in JUnit, which report to the compiler what is to be done with the code that follows the annotation. For instance, @Test is an annotation in JUnit, indicating that the code that follows this annotation has a testing code.

JUnit annotations are genuinely simple. Some of the annotations are listed below:

**@Before:** This annotation is used to run the JUnit code before every test. It is used for initializing different methods before the test executions. It can be initializing variables, creating the entry in the DBMS, or anything else.
**@Test:** This annotation carries the code required for the initial test. After the @Before code has been run (if placed), the @Test annotation executes.
**@After:** This annotation is used for indicating the code which has to run after the execution of the testing code. It is generally used for destroying the variables and freeing up the memory.
**@BeforeClass:** The BeforeClass annotation specifies that this code must run before running all the other tests. This code must be static and will run for a single time. The code following @Beforeclass runs only once, but the code following @Before runs every time the test is required. For example, If the test has to run hundred times, @Before is executed hundred times, but the @BeforeClass code runs only once.
**@AfterClass:** The AfterClass annotation specifies that the code following this assertion or annotation is performed only after all the tests are executed. Analogous to the @BeforeClass annotation, the code following @AfterClass runs only once after all the tests have been completed.

**Advantages of JUnit**

- JUnit is an open-source framework for writing and running tests.
- JUnit is a very fundamental framework. The time consumption is less and it is easier to understand.
- JUnit tests enable you to build codes better and faster. Annotations are provided in JUnit to help in the identification of test techniques.
- Test runners are provided for assisting in the execution of tests.
- Assertions and annotations are used for testing.
- JUnit lists failed test cases in a separate section for debugging with ease.
- JUnit displays the test progress in a green bar when the test is executing well and a red bar when the test is failing.
- Automation Testing with JUnit can be grouped into test suites that contain test cases and sometimes other test suites.
- JUnit tests can be automated, and they check and provide quick feedback on their results. There is no need to go through a report of test findings by hand.

**Summing it up**

JUnit Automation testing is the most popular and favored testing method if the project design has been developed using Java. It is compelling and is constantly evolving for better execution of test cases. It has become one of the most preferred choices for Test-Driven Development (TDD) cycle.

Selenium is an accessible and the most convenient tool in the context of automated web and app testing, and using it along with JUnit has even more advantages. JUnit supports multiple annotations and assertions.

However, irrespective of how well-crafted tests are made, they cannot be conclusive if it is not run on an actual device. Simulators and emulators cannot reproduce end-user conditions appropriately, particularly in aspects such as low batteries, weak networks, and many more. For you to balance these inadequacies, a test should be run directly on a cloud-based actual device. In such a case, JUnit is the most favored framework available.