Helping Testers: TestNG Tutorial (Annotations, Priority and Test Suite )

TestNG is a testing framework inspired from JUnit and NUnit but introducing some new functionalities that make it more powerful and easier to use, such as:

NG denotes Next Generation.

Annotations.
Run your tests in arbitrarily big thread pools with various policies available (all methods in their own thread, one thread per test class, etc...).
Test that your code is multithread safe.
Flexible test configuration.
Support for data-driven testing (with @DataProvider).
Support for parameters.
Powerful execution model (no more TestSuite).
Supported by a variety of tools and plug-ins (Eclipse, IDEA, Maven, etc...).
Default JDK functions for runtime and logging (no dependencies).
Dependent methods for application server testing.

TestNG is designed to cover all categories of tests: unit, functional, end-to-end, integration, etc...

Benefits of using TestNG

TestNG is similar to JUnit but introduces some new features that make it more powerful and easier to use. Below are some of the benefits Appium Java users can enjoy with TestNG:

More annotations: TestNG has an extensive choice of annotations. See a full list of annotations available in TestNG.
Test Grouping: The groups attribute with the @Test annotation eases the grouping of test cases.
Test Prioritization: Using the priority attribute to set different priorities for each test case.
Parameterized Tests: Using parameterized tests makes it easy to run the same test over and over using different values.
Parallel Testing: It’s possible and easy to parallelize test execution with the parallel attribute.

Refer: https://testng.org/doc/eclipse.htm

TestNG Annotations?

Annotations, in general, mean a comment or a note on a object, TestNG annotations are the code that is written inside source test code logic to control the flow of the execution of tests. It is essential to annotate your methods in TestNG to run the tests. TestNG will ignore the method which does not contain an annotation since it won’t know when to execute this method.

A TestNG annotation starts from the symbol @ and whatever follows is the annotation name. These names are predefined.

Types of TestNG Annotations:

In TestNG, there are #10 types of annotations:

@BeforeSuite – The @BeforeSuite method in TestNG runs before the execution of all other test methods.
@AfterSuite – The @AfterSuite method in TestNG runs after the execution of all other test methods.
@BeforeTest – The @BeforeTest method in TestNG runs before the execution of all the test methods that are inside that folder.
@AfterTest – The @AfterTest method in TestNG executes after the execution of all the test methods that are inside that folder.
@BeforeClass – The @BeforeClass method in TestNG will run before the first method invokes of the current class.
@AfterClass – The @AfterClass method in TestNG will execute after all the test methods of the current class execute.
@BeforeMethod – The @BeforeMethod method in TestNG will execute before each test method.
@AfterMethod – The @AfterMethod method in TestNG will run after each test method is executed.
@BeforeGroups – The @BeforeGroups method in TestNG run before the test cases of that group execute. It executes just once.
@AfterGroups – The @AfterGroups method in TestNG run after the test cases of that group execute. It executes only once.

Order of Annotations

Example of code:

import org.testng.annotations.AfterClass;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.AfterSuite;
import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.BeforeSuite;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;
 
public class TestNG {
 @Test
 public void testCase() {
 
 System.out.println("This is the Test Case");
 
 }
 
 @BeforeMethod
 
 public void beforeMethod() {
 
 System.out.println("This will execute before every Method");
 
 }
 
 @AfterMethod
 
 public void afterMethod() {
 
 System.out.println("This will execute after every Method");
 
 }
 
 @BeforeClass
 
 public void beforeClass() {
 
 System.out.println("This will execute before the Class");
 
 }
 
 @AfterClass
 
 public void afterClass() {
 
 System.out.println("This will execute after the Class");
 
 }
 
 @BeforeTest
 
 public void beforeTest() {
 
 System.out.println("This will execute before the Test");
 
 }
 
 @AfterTest
 
 public void afterTest() {
 
 System.out.println("This will execute after the Test");
 
 }
 
 @BeforeSuite
 
 public void beforeSuite() {
 
 System.out.println("This will execute before the Test Suite");
 
 }
 
 @AfterSuite
 
 public void afterSuite() {
 
 System.out.println("This will execute after the Test Suite");
 
 }
 
 }

OUTPUT:

[RemoteTestNG] detected TestNG version 7.4.0

This will execute before the Test Suite

This will execute before the Test

This will execute before the Class

This will execute before every Method

This is the Test Case

This will execute after every Method

This will execute after the Class

This will execute after the Test

PASSED: testCase

TestNG will run the execution based on Alphabetical order if there are multiple test cases

Test Priority in TestNG

Although TestNG annotations decide in which order the tests will run, priorities do more or less the same job.

The priorities are an additional option that we can put to use with the test annotations. This attribute decides the priority of the annotation. But remember that priority check happens after the annotation check by TestNG. So the TestNG annotation hierarchy is followed first and then priority-based execution. The larger the priority number, the lower is its priority. So a method with priority 1 will run after the test with priority 0.

@Test(priority=1)
    public void b_method(){
    System.out.println("B Method");
    }
 
@Test(priority=1)
    public void a_method(){
    System.out.println("A method");
    }

TestNG Test suite:

the collection of TestNG Tests together is called a Test Suite. A test suite can run multiple tests at once by executing the test suite. Additionally, these test cases can be dependent on each other or may have to be executed in a specific order independently. Moreover, running the TestNG test suite gives us the capability to manage our test execution.

TestNG does not let us define the test suites inside the test code or the main testing source code. Hence, we need to create a TestNG XML file for the same and execute this file.

How To Create A TestNG XML?

To create TestNG XML file for running the TestNG test suites, follow the given steps:

1.Right-click on the Project folder, go to New and select File as shown in the below image.

2. In New file wizard, add filename as ‘testng.xml‘ and click on the Finish button.

3. Finally, it will add a testng.xml file under your project folder, and we are all set to write our first TestNG XML to run TestNG test suites.

After that, add the below-given code in your testng.xml file.

<!DOCTYPE suite SYSTEM "https://testng.org/testng-1.0.dtd" >
<suite name="Test-Suite" >
   <test name="HelpingTesters" >
       <classes> 
          <class name="testAndroid.FirstTestNG" />
       </classes>
   </test>
 </suite>

This TestNG XML code does not need any explanation. It is effortless to read and write.

<suite> – The suite tag can be given any name and denotes the test suite name.
<test> – The test tag can be given any name and indicates your test sets.
<classes> – This is the combination of your package name and test case name and cannot write anything else.

How to Run the TestNG Suite?

Run the test by right click on the testng.xml file and select Run As > TestNG Suite.

OUTPUT:

Test Suite:

To create testNG test suite in XML file all you need to do is add your test classes in xml file as like above .xml file and run As TestNG Test suite.

Example:

<!DOCTYPE suite SYSTEM "https://testng.org/testng-1.0.dtd" >

<suite name="Test-Suite" >

   <test name="HelpingTesters" >

       <classes> 

          <class name="testAndroid.FirstTestNG" />

        <class name="testAndroid.AnotherTestNG" />

       </classes>

   </test>

 </suite>

Include/ exclude methods in testng.xml

Here we can ignore/ run out test cases by using Exclude/Include tags in xml file.

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE suite SYSTEM "https://testng.org/testng-1.0.dtd"> <suite name="FirtSuite"> <test thread-count="5" name="TestSuite"> <classes> <class name="testAndroid.Testng2"> <methods> <include name="test4"></include> <exclude name="test5"></exclude> <include name="test6"></include> </methods> </class>

</classes>

</test>  </suite>

Output:

This is test case 6 =============================================== FirtSuite Total tests run: 1, Passes: 1, Failures: 0, Skips: 0 ===============================================

Helping Testers

TestNG Tutorial (Annotations, Priority and Test Suite )