Structuring integration tests using JUnit categories by features, API or type of tests

Why structure your integration tests ?

When the number of integration tests grow is a good practice to separate the tests based on the feature/api that they are testing.

The advantages of doing this are:

• easier to maitain as the tests for a specific feature/API are grouped in a specific category
• easier to run the tests only for that specific category when only that feature changes to get faster feedback
• easier to group the tests when running them in Jenkins/Travis CI or any other CI so that multiple jobs can be run in parallel and also when a job fails imediatelly the team will know which feature/API has failed

How is this done using Java, JUnit and Maven ?

1. Create a basic Maven project
2. Create a new package in the src/main/java with the name “tutorial.junit.categories” in which the different categories will be added.
   The structure of the project should look like below:
3. Create a few JUnit test cases in a few test classes. In our case we are going to create:
   •  LoginApiTestIT.java
   •  SearchApiTestIT.java
4. Create a few categories in which we want to split the tests. In our case we are going to split them as follows:
   • LoginApiCategory – tests run against the login api
   • SearchApiCategory – tests run against the search api
   • SmokeTestCategory – which includes tests from either Login or Search API tests that we want to run as smoke tests
5. A category is just an empty interface as in the example below:
6. Setting the category for each of the tests. For setting the category we just need to add the @Category annotation either at the class or method level as  below.
7. Example below:

   
   package tutorial.junit;
   
   import org.junit.Test;
   import org.junit.experimental.categories.Category;
   
   import tutorial.junit.categories.LoginApiCategory;
   import tutorial.junit.categories.SmokeTestCategory;
   
    @Category(LoginApiCategory.class)
    public class LoginApiTestIT {
   
    @Category(SmokeTestCategory.class)
    @Test
    public void shouldReturn200ForValidCredentials(){
       System.out.println("Running Login API tests - Positive case");
    }
   
   @Test
    public void shouldReturn404ForInvalidCredentials(){
       System.out.println("Running Login API tests - Negative case");
     }
   }
   
   

8. Running the tests based on the category is pretty simple using the Maven commands below. Open the Maven pom.xml file location in your terminal and run the following commands:
   • running the login tests

     
     mvn clean install -P integration-test -Dgroups="tutorial.junit.categories.LoginApiCategory"

   • running the search tests

     
     mvn clean install -P integration-test -Dgroups="tutorial.junit.categories.SearchApiCategory"

   • running the smoke tests which include tests from login and search

     mvn clean install -P integration-test -Dgroups="tutorial.junit.categories.SmokeTestCategory"

integration tests junit categories