PAGE-9: DEPENDENCY IN TestNG

Dependency is a feature in TestNG that allows a test method to depend on a single or a group of test methods. This will help in executing a set of tests to be executed before a test method. Method dependency only works if the “depend-on-method” is part of the same class or any of the inherited base class (i.e. while extending a class).

Method dependency only works with other methods that belong to the same class or in one of the inherited classes but not across different classes. In case you need a test method that exists in a separate class; you can achieve this by assigning the said test method to a group and configuring the dependent test method to be dependent on that group.

Test with single test method dependency

TestNG lets you create a sample test method that depends on another test method of the same class.

public class DependentTestExamples

{

    @Test(dependsOnMethods = { "testTwo" })

    public void testOne() {

        System.out.println("Test method one");

    }

  @Test

    public void testTwo() {

        System.out.println("Test method two");

    }

}

The preceding test class contains two test methods which print a message name onto the console when executed. Here, test method testOne depends on test method testTwo. This is configured by using the attribute dependsOnMethods while using the Test annotation.

Let’s run the tests now.

Test method two

Test method one

PASSED: testTwo

PASSED: testOne

In the above test result you can see the message Test method two printed before the Test method one message. This shows that the testOne method got executed after testTwo as it depends on testTwo.

Test with multiple test methods dependencies

Sometimes it may be required for a test method to depend upon multiple other methods. This feature is very well supported by TestNG as part of the dependency support.

public class DependentTestExamples {     @Test(dependsOnMethods = { "testTwo", "testThree" })     public void testOne() {         System.out.println("Test method one");     }  @Test     public void testTwo() {         System.out.println("Test method two");     }  @Test     public void testThree() {         System.out.println("Test method three");     } }

The preceding test class contains three test methods which print a message name onto the console when executed. Here test method testOne depends on test methods testTwo and testThree. This is configured by using the attribute dependsOnMethods while using the Test annotation.

Let’s run the test now.

Test method three Test method two Test method one PASSED: testThree PASSED: testTwo PASSED: testOne

By looking at the console message we can see that methods testTwo and testThree got executed before testOne.

Inherited Dependency Test:

Till now we have seen samples in which the dependent test methods were part of the same class. Dependency on test methods can only be mentioned for test methods that belong to the same class or any of the inherited base classes. Let’s see how TestNG executes the test methods when the dependent methods are part of the inherited base class.

public class ParentClassTest {     @Test(dependsOnMethods = { "testTwo" })     public void testOne() {         System.out.println("Test method one");     }    @Test     public void testTwo() {         System.out.println("Test method two");     } }  public class DependentTestExamples extends ParentClassTest {     @Test(dependsOnMethods = { "testOne" })     public void testThree() {         System.out.println("Test three method in Inherited test");     }  @Test     public void testFour() {         System.out.println("Test four method in Inherited test");     } }

The preceding test class contains two test methods which print a message name onto the console when executed. Here test method testThree depends on test method testOne. This is configured by using the attribute dependsOnMethods while using the Test annotation.

Let’s run the test now.

Test four method in Inherited test Test method two Test method one Test three method in Inherited test PASSED: testFour PASSED: testTwo PASSED: testOne PASSED: testThree

As you can see from the test results the sequence of execution is testFour, testTwo, testOne, and lastly, testThree. AstestThree depends on testOne and on testTwo, TestNG executes all the test methods based on the dependency and finally the respective test method.

Test that depends on a group

Similar to dependent methods TestNG also allows test methods to depend on groups. This makes sure that a group of test methods get executed before the dependent test method.

public class DependentTestExamples {     @Test(dependsOnGroups = { "test-group" })     public void groupTestOne() {         System.out.println("Group Test method one");     }     @Test(groups = { "test-group" })     public void groupTestTwo() {         System.out.println("Group test method two");     }     @Test(groups = { "test-group" })     public void groupTestThree() {         System.out.println("Group Test method three");     } }

The preceding test class contains two test methods which print a message name onto the console when executed. Here, test method testOne depends on test method testTwo. This is configured by using the attribute dependsOnMethods while using the Test annotation.

Let’s run the tests now.

Group Test method three Group test method two Group Test method one PASSED: groupTestThree PASSED: groupTestTwo PASSED: groupTestOne