Actually there exist 2 marshaller implementations for BPMN - the "legacy" and the new one.

The goals for this task are:

• Remove classes & tests related to legacy BPMN marshallers
  • Remove classes and tests for org.kie.workbench.common.stunner.bpmn.backend.legacy package (module kie-wb-common-stunner-bpmn-backend)
  • Remove classes and tests for org.kie.workbench.common.stunner.bpmn.backend.marshall.json package (module kie-wb-common-stunner-bpmn-backend)
  • Remove other classes and tests in kie-wb-common-stunner-bpmn-backend module related to legacy marshallers (BPMNDiagramMarshaller, etc)

• Also, in the kie-wb-common-stunner-bpmn-backend module, there are some tests that are comparing the marshalling/unmarshalling results produced by both legacy and new marshallers (eg: MigrationDiagramMarshallerTest, etc). In order to try not dropping this work, one option could be refactoring those tests to use, instead of the legacy marshallers to be removed in Stunner, the actual marshallers on the jbpm-designer (by adding a test scope dependency to jbpm-designer-backend)