Priority concept in TestNG

The priority attribute in TestNG plays a crucial role in managing the execution order of test methods. By default, TestNG executes test methods in the alphabetical order of their names. However, in real-world scenarios, this default behavior may not be desirable or sufficient, as some tests might need to be executed before others due to dependencies among them. This is where the priority attribute becomes particularly useful.

How Priority Works

The priority attribute is used within the @Test annotation to specify the order in which test methods should be executed. It takes an integer value, and TestNG executes test methods in ascending order based on their priority values. If no priority is set, TestNG assigns a default priority of 0 to the test method.

Example Usage

package priorities;

import org.testng.annotations.Test;

public class PriorityTestng {

@Test(priority = 1)

public void display()

{

System.out.println(" display method");

}

@Test(priority = 2)

public void show()

{

System.out.println("show method");

}

@Test(priority = 3)

public void print()

{

System.out.println("print method");

}

}

Key Points

• Default Priority: If the priority is not specified for a test method, TestNG assigns a priority of 0. This means that test methods without a specified priority will be executed before those with a specified priority, assuming their names come first alphabetically.
• Same Priority: When multiple test methods have the same priority, TestNG defaults to executing them in alphabetical order based on their method names.
• Negative Priority: TestNG allows for negative priority values. This can be useful when you need to ensure certain methods always run before others without having to assign a priority to every test method.
• Dependency Over Priority: If test methods are configured with dependencies (using the dependsOnMethods or dependsOnGroups attributes), TestNG prioritizes respecting these dependencies over the specified priority. This means a test method won’t run until all of its dependencies have run successfully, regardless of the priority values.
• Use Cases: Priority is particularly useful in scenarios where tests must be executed in a specific order due to dependencies on the state produced by earlier tests. However, it’s generally a good practice to make tests independent of each other when possible.