{"id":110056,"date":"2020-06-12T10:17:00","date_gmt":"2020-06-12T10:17:00","guid":{"rendered":"https:\/\/www.softwaretestinghelp.com\/?page_id=110056"},"modified":"2025-04-01T08:14:47","modified_gmt":"2025-04-01T08:14:47","slug":"junit-tutorial","status":"publish","type":"page","link":"https:\/\/www.softwaretestinghelp.com\/junit-tutorial\/","title":{"rendered":"JUnit Tutorial For Beginners – What Is JUnit Testing"},"content":{"rendered":"

This JUnit Tutorial for Beginners explains what is Unit Testing, Test Coverage and What is JUnit Testing Framework along with Examples of JUnit Testcases:<\/strong><\/p>\n

This JUnit series has been prepared to focus on our audiences who are absolute beginners as well as those who have a good knowledge of Java or JUnit with a keen interest in learning JUnit.<\/p>\n

The series in totality has been put forth in such a way in which you will able to interpret the difference between JUnit 4 and Junit 5.<\/p>\n

Let’s start exploring JUnit now!!<\/strong><\/em><\/p>\n

<\/strong><\/em><\/p>\n

\"JUnit<\/a><\/p>\n

List Of Tutorials In This JUnit Series<\/span><\/h2>\n

Tutorial #1:<\/strong><\/span> JUnit Tutorial For Beginners – What Is JUnit Testing?<\/a>[This Tutorial]
\nTutorial #2:<\/strong><\/span> Download, Install And Configure JUnit In Eclipse<\/a>
\nTutorial #3:<\/strong><\/span> JUnit Tests: How To Write JUnit Test Cases With Examples<\/a>
\nTutorial #4:<\/strong><\/span> What Is A JUnit Test Fixture: Tutorial With JUnit 4 Examples<\/a>
\nTutorial #5:<\/strong><\/span> Multiple Ways To Execute JUnit Tests<\/a>
\nTutorial #6:<\/strong><\/span> List Of JUnit Annotations: JUnit 4 Vs JUnit 5<\/a>
\nTutorial #7:<\/strong><\/span> JUnit Ignore Test Case: JUnit 4 @Ignore Vs JUnit 5 @Disabled<\/a>
\nTutorial #8:<\/strong><\/span> JUnit Test Suite & Filtering Test Cases: JUnit 4 Vs JUnit 5<\/a>
\nTutorial #9:<\/strong><\/span> JUnit Test Execution Order: Order Of Tests JUnit 4 Vs JUnit 5<\/a>
\nTutorial #10:<\/strong><\/span> How To Use JUnit 5 Annotation @RepeatedTest With Examples<\/a>
\nTutorial #11:<\/strong><\/span> JUnit 5 Nested Class: @Nested Tutorial With Examples<\/a>
\nTutorial #12:<\/strong><\/span> JUnit 5 Custom Display Name & Conditional Test Execution<\/a>
\nTutorial #13:\u00a0<\/span><\/strong>JUnit Vs TestNG \u2013 What Are The Differences<\/a>
\nTutorial #14: <\/span><\/strong>JUnit API Additional Classes: TestSuite, TestCase And TestResult<\/a>
\nTutorial #15:<\/strong><\/span> JUnit Assertions: AssertEquals And AsssertSame With Examples<\/a>
\nTutorial #16:<\/span><\/strong> Grouped Assertions In JUnit 5 \u2013 Tutorial With Examples<\/a><\/p>\n

\n

JUnit Tutorial<\/h2>\n

In a typical, test-driven development (TDD) approach, developers focus on unit testing every chunk of the code they develop. The better the testing of a product, the better is the quality of it. We all know, that testing should go parallelly with each passing phase of the software development life cycle.<\/p>\n

Starting from requirement and analysis to design & development till maintenance, every phase should have an appropriate testing phase associated with it. Unit testing after development is what is advisable to build a robust application and to have an optimized code in place.<\/p>\n

What Is Unit Testing?<\/span><\/h3>\n

Unit testing is testing of a small logic or a code to verify that the output of the code is as expected on the input of a specific data and\/or on satisfying certain condition(s). Usually, the unit tests are supposed to be independent of the other tests.<\/p>\n

Unit tests are not feasible to test complex interfaces with another application or third party\/external services. A unit test targets only a small unit of code that could be just a method or a class.<\/p>\n

It helps the developer discover issues in the current logic and any regression failures due to the current change. Besides, it also provides insight into how the current code could impact future implementation.<\/p>\n

\"Unit<\/a><\/p>\n

Test Coverage<\/span><\/h3>\n

The percentage of code that is tested by unit tests is called test coverage<\/em>.<\/p>\n

The objective is to have better and more test coverage of the code which in future continues to add up to the regression test suite and helps to increase automated test execution and verification, thereby, reducing the manual effort involved in regression testing.<\/p>\n

Running tests automatically helps to identify software regression issues introduced by changes in the current code. Having a high-test coverage of your code allows you to continue developing features without having to perform a lot of manual tests.<\/p>\n

Many come with a question as to how much test coverage is essential<\/em>. The answer to this question is that there is no hard and fast rule to how much coverage of tests is essential; it is all judgemental. The judgment gets better with experience on the application workflow and historic knowledge of the defects found so far.<\/p>\n

Efficient tests need not necessarily mean having 100% test coverage or incorporating automation tests and\/or unit tests for every single branch or path coverage.<\/p>\n

Certain trivial verifications like a validation error message for a mandatory field left blank that hasn\u2019t flawed since years need not be included in the regression suite.<\/p>\n

Manual Testing Vs Automated Testing<\/span><\/h3>\n

Unit Testing can be done via two approaches:<\/strong><\/p>\n

    \n
  1. Manual testing<\/li>\n
  2. Automated testing<\/li>\n<\/ol>\n

    \"JUnit<\/a><\/p>\n

    In both the approaches the workflow remains common:<\/strong><\/p>\n

      \n
    1. Creating a test case<\/li>\n
    2. Reviewing it<\/li>\n
    3. Rework if corrections needed<\/li>\n
    4. Execute the test case<\/li>\n
    5. Analyze the test results<\/li>\n<\/ol>\n

      Automated Testing is preferred over Manual Testing for the below reasons:<\/strong><\/p>\n\n

      \n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t
      Manual Testing<\/th>Automated testing <\/th>\n<\/tr>\n<\/thead>\n
      When a testcase is executed manually without an intervention of a tool is called manual testing.<\/td>When a testcase is executed with the help of a tool without much manual intervention is called automated testing.<\/td>\n<\/tr>\n
      Repetitive manual efforts are included.<\/td>Repetitive manual efforts may be avoided.<\/td>\n<\/tr>\n
      Human efforts in manual testing could be erroneous and time consuming. <\/td>Automation tests are faster and error free compared to the manual efforts. <\/td>\n<\/tr>\n
      Testing resources required are more for running every testcase manually thereby, adding to the investment in the resources.<\/td>Less testers are needed to execute automated tests using the designated automated tool(s) hence there is less investment in testing resources thus adding to the profitability.<\/td>\n<\/tr>\n
      Manual testing has to be limited to a small test coverage considering the timeline restrictions. Hence, there is a risk of skipping many test scenarios thus leading to risk of defect leakage as well.<\/td>Many different test scenarios can be automated and can be executed multiple times even under time and resource crisis hence leading to better test coverage and better quality of the deliverable.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n\n

      Unit Test Framework<\/span><\/h3>\n

      We may have the next question as to what does a typical automation unit test case looks like and the framework it follows. The developers use the Unit Test framework<\/strong> for creating automated unit test cases.<\/p>\n

        \n
      1. In order to verify if the code is logically working as expected, a testcase with a specific checkpoint or verification criterion is created.<\/li>\n
      2. When the testcase is executed, either the criteria\/condition passes or fails.<\/li>\n
      3. A log is generated as per the testcase workflow.<\/li>\n
      4. The framework will report a summarized result on the passed test cases and failed ones.<\/li>\n
      5. Per the severity of the failure, the testcase may not proceed further and may stop subsequent execution.<\/li>\n
      6. There could be certain low severe failures that get reported in the log however it doesn\u2019t show a hard stop but continues without blocking the further test steps.<\/li>\n<\/ol>\n

        What Is JUnit?<\/h2>\n

        JUnit is an open-source framework that is used for writing and executing unit tests in Java programming language. It is one of the best-known unit testing frameworks.<\/p>\n

        The below image shows the different well-known automation unit testing tools.<\/strong><\/p>\n

        \"Junit<\/a><\/p>\n

        Enlisted below are the attributes that JUnit is packaged with:<\/strong><\/p>\n