Asyncstream | Camunda BPMN testing with Mockito

Unit testing of a BPMN is not simple as that of a java class. Camunda mockito extension has provided a simple implementation to create unit tests for BPMN. In this article we will walk through a sample test case of customer activation BPMN in the cloudmessage platform.

Maven Configuration

<dependency>
        <groupId>org.camunda.bpm.extension.mockito</groupId>
        <artifactId>camunda-bpm-mockito</artifactId>
        <version>4.10.0</version>
        <scope>test</scope>
</dependency>

BPMN Diagram

In the customer activation process, systems sends a message to the customer with activation link and then wait for the customer action. When the customer clicks on the link a message will be sent back to the system to resume the process.

Testcase Implementation

The full implementation of this testcase can be viewed here

First step is to create a process engine.

@Rule
   public final ProcessEngineRule processEngineRule = new ProcessEngineRule(testAwareProcessEngineConfiguration().buildProcessEngine());

As this BPMN has message send and recieve tasks , we need to create two constants for message name and recieve task id.

   private static final String MESSAGE_ACTIVATION_RESULT = "Message_Activation_Result";
   private static final String RECIEVE_ACTIVITY="process_activation_result";

In the test method call the autoMock for the bpmn process which registers mocks for TaskListner, ExecutinListner and JavaDelegate.

   autoMock("bpmn/customer-activation.bpmn");

Asserts that all the necessary mocks are available.

   assertThat(Mocks.get("startActivation")).isNotNull();
   assertThat(Mocks.get("processActivationResult")).isNotNull();
   assertThat(Mocks.get("completeActivation")).isNotNull();
   assertThat(Mocks.get("sendActivationRequest")).isNotNull();

Configure the deployment with a mock to the recieve message activity.

   processEngineRule.manageDeployment(registerCallActivityMock(RECIEVE_ACTIVITY)
        .onExecutionWaitForMessage(MESSAGE_ACTIVATION_RESULT)
        .deploy(processEngineRule));

Verify the mocks for the first to activities using the verify methods of DelegateExpressions.

    
   verifyExecutionListenerMock("startActivation").executed(); // For Listeners
   verifyJavaDelegateMock("sendActivationRequest").executed(); // For Delegates

As the 3rd stage of the BPMN is message receieve activity, automate it by correlateMessage with message name.

   processEngineRule.getRuntimeService().correlateMessage(MESSAGE_ACTIVATION_RESULT);

Conclusion

In this article, the testing of a BPMN process using camunda and mockito is covered with a simple project setup . The source code of this project is available in the cloudmessage stream Github repository.