Ability to mock a subprocess (called activity)

[sburkard]

Description

It would be great if one could mock a called activity in a zeebe process test.

Use case: Model technical processes and call them from a main "business view" process

• I have a main process model that represents the "business view" of the whole process
• Let's say a workflow task need to insert data into a backend system
• Because this is done in multiple steps through an API, it is modeled in a dedicated technical process (multiple tasks with compensation tasks etc, kind of Saga-Process)
• To hide these technical details in the business model, I use a call activity step to call the technical process

So it is kind of the same situation as when I want to test a service or similar. I want to mock away the dependencies of the system under test for all the well known reasons.

I want to test the business process by mocking away technical (sub-)processes and just say what the outcome of the technical process should be for my test case.

[remcowesterhoud]

Hi @sburkard, thank you for raising this. I do see value in adding a simple way for users to mock away call activities.

For now I can provide you with a workaround. Instead of mocking the called process you could deploy it with just a start event.

If you give the process the same id as the called process you can save yourself the hassle of having to execute all the tasks in the called process.

This is also how we use it ourselves:

  private void deployFakeChildProcess(final String processId, final Map<String, String> outputVariables) {
      final var builder = Bpmn.createExecutableProcess(processId).startEvent();
      outputVariables.forEach(builder::zeebeOutputExpression);
      var model = builder.done();
      client.newDeployResourceCommand().addProcessModel(model, processId + ".bpmn").send().join();
  }

Do note that here we use the BPMN Model api instead of deploying it from a file.

[sburkard]

Hi @remcowesterhoud

Excellent workaround, thank you very much.

[saig0]

Note

Heads up! We are building a new Java testing library for Camunda 8.6. The new library will replace Zeebe Process Test.
Read more about upcoming changes here and stay tuned for updates. 🚀