In this article, I will guide you how to run JUnit tests in a determined order. You know, when run a whole test class, the execution order of test methods matters if input of a test depends on output of others. For example, when testing CRUD operations, testList() method would depend on testCreate() method – so when running the test class, the testCreate() must run before testList().

By default, JUnit executes tests in a specific order of its own, but not predictable. JUnit 5 allows programmers to override that default, to run tests in a determined order: alphanumeric order or numeric order.

Suppose that we have a test class as follows:

public class ProductRepositoryTests {

	@Test
	public void testCreateProduct() {
	}
	
	@Test
	public void testFindProductByName1() {
	}
	
	@Test
	public void testFindProductByName2() {
	}
	
	@Test
	public void testFindProductByName3() {
	}	
	
	@Test
	public void testListProducts() {
	}	
	
	@Test
	public void testUpdateProduct() {
	}
	
	@Test
	public void testDeleteProduct() {
	}
}

Let’s see how to enforce tests order for this test class in JUnit 5.

 

1. Run Tests in Alphanumeric Order

To run tests in the order of test method names by alphanumeric order, just specify the @TestMethodOrder(Alphanumeric.class) annotation for the test class:

import org.junit.jupiter.api.MethodOrderer.Alphanumeric;
import org.junit.jupiter.api.TestMethodOrder;

@TestMethodOrder(Alphanumeric.class)
public class ProductRepositoryTests {

	@Test
	public void testCreateProduct() {
	}
	
	@Test
	public void testFindProductByName1() {
	}
	
	@Test
	public void testFindProductByName2() {
	}
	
	@Test
	public void testFindProductByName3() {
	}	
	
	@Test
	public void testListProducts() {
	}	
	
	@Test
	public void testUpdateProduct() {
	}
	
	@Test
	public void testDeleteProduct() {
	}
}

Run this test class and the test methods will be executed in the following order:

testCreateProduct
testDeleteProduct
testFindProductByName1
testFindProductByName2
testFindProductByName3
testListProducts
testUpdateProduct

Note that JUnit executes tests in alphanumeric order, meaning by ascending order of characters and numbers in method names.

 

2. Run Tests in Numeric Order

You can run tests by numeric order by using the @TestMethodOrder(OrderAnnotation.class) annotation at class level and specify a number for each test method using the @Order annotation. For example, update the above test class as follows:

import org.junit.jupiter.api.MethodOrderer.OrderAnnotation;
import org.junit.jupiter.api.Order;

@TestMethodOrder(OrderAnnotation.class)
public class ProductRepositoryTests {
	
	@Test
	@Order(1)
	public void testCreateProduct() {
	}
	
	@Test
	@Order(2)
	public void testFindProductByName1() {
	}
	
	@Test
	@Order(3)
	public void testFindProductByName2() {
	}	
	
	@Test
	@Order(4)
	public void testFindProductByName3() {
	}
	
	@Test
	@Order(5)
	public void testListProducts() {
	}	
	
	@Test
	@Order(6)
	public void testUpdateProduct() {
	}
	
	@Test
	@Order(7)
	public void testDeleteProduct() {
	}
}

Run this test class and you will see the test methods run in the following order:

testCreateProduct
testFindProductByName1
testFindProductByName2
testFindProductByName3
testListProducts
testUpdateProduct
testDeleteProduct

So that’s quite easy to specify tests order in JUnit 5, right? You can also watch the video below:

 

Other JUnit Tutorials:

• JUnit Tutorial for beginner with Eclipse
• How to compile and run JUnit tests in command line
• JUnit Test Suite Example - How to create and run test suite in command line and Eclipse
• JUnit Test Exception Examples - How to assert an exception is thrown