This tutorial will give an insight into JUnit and its usage in selenium script. This is tutorial #11 in our comprehensive Selenium tutorials series.
JUnit is an open-source unit testing tool used to test small/large units of code. To run the JUnit test, you don’t have to create a class object or define the main method. JUnit provides an assertion library that is used to evaluate the test result.
Annotations of JUnit are used to run the test method. JUnit is also used to run the Automation suite having multiple test cases.
Table of Contents:
Usage of JUnit in Selenium Scripts
Adding JUnit Library in Java Project
First, we will learn how to add a JUnit library to your Java project:
Step #1: Right click on Java project->Build Path->Configure Build path
Step #2: Click Libraries->Add Library
Step #3: Click on JUnit.
Step #4: Select JUnit4-> Finish
Step #5: Click OK.
Many frameworks, like Data Driven Framework, Keyword Driven Framework, and Hybrid Framework, use the JUnit tool as a test runner and will help start the batch execution and reporting.
JUnit Annotations Used in Selenium scripts
There are many annotations available in Junit. Here we have described a few annotations frequently used in Selenium scripts and frameworks.
#1) @Test
@Test annotation is used to run a Junit test.
Example:
@Test
public void junitTest()
{
System.out.println("Running Junit test");
Assert.assertEquals(1,1);
}
How to Run a JUnit test:
Navigate to run ->Run as JUnit test
#2) @Before
@Before annotation is used to run any specific test before each test.
public class Junttest {
@Before
public void beforeTest(){
System.out.println("Running before test");
}
@Test
public void junitTest(){
System.out.println("Running Junit test");
}
}
Output:
Running before test
Running Junit test
Example of before annotation using two JUnit test methods.
public class Junttest {
@Before
public void beforeTest(){
System.out.println("Running before test");
}
@Test
public void junitTest(){
System.out.println("Running Junit test");
}
@Test
public void secondJunitTest(){
System.out.println("Running second Junit test");
}
}
Output:
Running before test
Running JUnit test
Running before test
Running the second JUnit test
Before running the JUnit test method beforeTest method will run. Similarly, before running the secondJuntiTest again beforeTest method will run and produce output like the above.
#3) @BeforeClass
This method executes once before running all tests. The method has to be a static method. Initialization of properties files, databases, etc is done in the beforeClass method.
public class Junttest {
@BeforeClass
public static void beforeClassTest(){
System.out.println("Executed before class method");
}
@Test
public void junitTest(){
System.out.println("Running Junit test");
}
@Test
public void secondJunitTest(){
System.out.println("Running second Junit test");
}
}
Output:
Executed before the class method
Running JUnit test
Running the second JUnit test
#4) @After
This method executes after each test.
public class Junttest {
@Test
public void junitTest(){
System.out.println("Running Junit test");
}
@After
public void afterTest(){
System.out.println("Running after method");
}
}
Output:
Running JUnit test
Running after method
#5) @AfterClass
Like @BeforeClass, @AfterClass executes once after executing all test methods. Like a @BeforeClass method, the @AfterClass method has to be a static method.
public class Junttest {
@Test
public void junitTest(){
System.out.println("Running Junit test");
}
@Test
public void secondJunitTest(){
System.out.println("Running second Junit test");
}
@AfterClass
Public static void afterClassTest(){
System.out.println("Running afterclass method");
}
}
Output:
Running JUnit test
Running the second JUnit test
Running after-class method
JUnit assertions are used to validate certain conditions and stop the execution of the program if the conditions are not satisfied.
#6) Parameterized JUnit class
A parameterized class is used to run the same scenario with multiple datasets.
Below is an example to pass multiple parameters in a JUnit test.
@Parameters annotation tag is used to pass multiple data. Here, we have taken 2*2 dimensional array and the data can be visualized below:
@RunWith(Parameterized.class)
public class Junttest {
public String name;
public int age;
public Junttest(String name,int age){
this.name=name;
this.age=age;
}
@Test
public void testMethod(){
System.out.println("Name is: "+name +" and age is: "+age);
}
@Parameters
public static Collection<Object[]> parameter(){
Object[][] pData=new Object[2][2];
pData[0][0]="Tom";
pData[0][1]=30;
pData[1][0]="Harry";
pData[1][1]=40;
return Arrays.asList(pData);
}
}
JUnit Assertions
JUnit assertEquals: This checks if the two values are equal and assertion fails if both values are not equal.
This compares Boolean, int, String, float, long, char, etc.
Syntax:
Assert.assertEqual(“excepted value”, ”actual value”);
Example:
Assert.assertEqual(“ABC”,”ABC”); //Both the strings are equal and assertion will pass.
Assert.assertEqual(“ABC”,”DEF”); //Assertion will fail as both the strings are not equal.
Assert.assertEqual(“Strings are not equal”, “ABC”,”DEF”); //message will be thrown if the equal condition is not satisfied.
Below is an example of the use of JUnit assertion in selenium:
String username=driver.findElement(By.id(“username”)).getText();
String password=driver.findElement(By.id(“password”)).getText();
Assert.assertEqual(“Mismatch in both the string”, username, password);
In the above example, the assertion will fail as both strings are not equal. One is the text of the username field and the other is the text of the password field.
JUnit assertTrue: Returns true if the condition is true and assertion fails if the condition is false.
Assert.assertTrue(“message”, condition);
Assert.assertTrue(“Both the strings are not equal”, (“HelloWorld”).equals(“HelloWorld”));
Here assertion will pass as both the strings match. It will print the message if the assertion fails.
JUnit assertFalse: Returns true if the condition is false and assertion fails if the condition is true.
Assert.assertFalse(“message”, condition);
Assert.assertFalse(“Both the strings are equal”, (“Hello”).equals(“HelloWorld”));
There will not be any assertion error as the condition is false.
Conclusion
Most of the programmers use JUnit, as it is easy and does not take much effort to test. A simple green or red bar will show the actual result of the test. Junit makes life easy as it has its own set of libraries and annotations. Here we have also described commonly used annotations used with selenium scripts and framework.
More details about the framework and use of JUnit annotations will be discussed in the upcoming tutorial, which is dedicated exclusively to framework design using Junit. This tutorial will help us in designing the framework using Junit.
Next Tutorial #12: In the next tutorial, we will discuss all about TestNG, its features, and its applications. TestNG is an advanced framework designed in a way to leverage the benefits of both the developers and testers.
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God bless every body, it is great help.
hello all,
really very helpful website.
can you please explain bit more “#6. Parameterized Junit class”.
not understand clearly.
Please share some more details for the parametrised class used. Though we are able to implement it,
But it would be great if you can share more details.
Small typo are
Assert.assertEqual –> should be Equals (s is missing)
Assert.assertEqual(“excepted value”, ”actual value”);
Really Very Nice Site To learn Selenium..!! Great Job..!! Thanks a Lot..!!
Attempt to view the Next post gives me ‘Error establishing a database connection’
@Ekaterina Can you please try again. It was an intermittent issue.
Superb !!!
Easy to understand .!!
Thankssss..
Hi All ,
I Ran Jnuit frame frame is working.but i have one small doubt how to pass the import the parameters Excel file in to junit.
use chaTGPT FOR IT
thanks for junit tutorial. can we have other frameworks info as well?
Sahir,
I think you have mentioned priority for TestNG framework.
Can anyone kindly help me with prioritizing tests in Junit ?
In JUnit4, it can be done as follows:
1. Declare @FixMethodOrder(MethodSorters.NAME_ASCENDING) before your test class.
2. For every test method name, prepend some string which will sort in the ASCENDING manner.
e.g.
@Test
public void firstMethod() {
}
@Test
public void secondMethod() {
}
Rename methods like:
@Test
public void test1_firstMethod() {
}
@Test
public void test2_secondMethod() {
}
The test is wrong with the parameterized.class.. you cant pass an object array into a string and int.. It will fail. the type has to be the same. Either int and int.. or string and string.
Hi Shruti, I have two questions:
1. Whenever I am running the @BeforeClass annotation, the second junit class runs before the first class.
Instead of this :
Executed before class method
Running Junit test
Running second Junit test
I get this :
Executed before class method
Running second Junit test
Running Junit test
Why did it happen?
Secondly, I am getting an initialization error if I run the parameterized example.
Hi Testing Team,
can you explain Parameterized Junit class example in details with list of package that are used in program.
@RunWith(Parameterized.class) = showing error here
Multiple markers at this line
– Type mismatch: cannot convert from Class to Class
When tried to run
Initilizationerror
java.lang.Exception: Custom runner class Parameterized should have a public constructor with signature Parameterized(Class testClass)
at org.junit.runners.model.InitializationError.(InitializationError.java:38)
at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:111)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createUnfilteredTest(JUnit4TestLoader.java:84)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:70)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:43)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:444)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Could you please tell us how to resolve this
@Rahul :
Answer for your first question:
The results are displayed randomly, if you want the results to appear as you want it, then user the “priority”
eg:
public class Junttest {
@BeforeClass
public static void beforeClassTest(){
System.out.println(“Executed before class method”);
}
@Test(priority=1)
public void junitTest(){
System.out.println(“Running Junit test”);
}
@Test(priority=2)
public void secondJunitTest(){
System.out.println(“Running second Junit test”);
}
}
In the above eg, the output would be :
Executed before class method
Running Junit test
Running second Junit test
Please explain the code level details for parameterization example. also explain the collection and objects
more information related to Parameterized
Thank you for the tutorial. It helps me a lot.
I ran the JunitTest and got the result like this:
Running before test
Running second Junit test
Running before test
Running Junit test
I am new to selenium and followed all the tutorials till chapter 10 with ease. But NOT able to understand this tutorial chapter11. I did the add library part. NOt sure about next steps as it is not clear and you have direclty started Annotations with no information about if it needs to be added to new program or the programs you have described in previous chapters. It would have been nice if you could provide complete program (with import required ) for the program and all in this tutorial. I am getting error while I m trying the above. Please help