chore(history): populate process instance treepath

related to #431

Author: HeleneW-dot

data-migrator/core/src/main/java/io/camunda/migration/data/impl/history/migrator/ProcessInstanceMigrator.java

@@ -29,6 +29,7 @@
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
+import java.util.Objects;
 import org.camunda.bpm.engine.history.HistoricActivityInstance;
 import org.camunda.bpm.engine.history.HistoricProcessInstance;
 import org.springframework.stereotype.Service;
@@ -123,7 +124,8 @@ public Long migrateTransactionally(HistoricProcessInstance c7ProcessInstance) {
 
       builder
           .historyCleanupDate(c8HistoryCleanupDate)
-          .endDate(c8EndTime);
+          .endDate(c8EndTime)
+          .treePath(generateTreepath(builder.build().rootProcessInstanceKey(), processInstanceKey));
 
       ProcessInstanceDbModel dbModel = convert(C7Entity.of(c7ProcessInstance), builder);
 
@@ -176,5 +178,20 @@ protected void resolveParentFlowNodeInstanceKey(
     }
   }
 
+  /**
+   * Generates a tree path for process instances in the format:
+   *    PI_rootProcessInstanceKey/processInstanceKey or
+   *    PI_processInstanceKey if this instance is the root of the hierarchy
+   *
+   * @param rootProcessInstanceKey the root process instance key
+   * @param processInstanceKey the process instance key
+   * @return the tree path string
+   */
+  public static String generateTreepath(Long rootProcessInstanceKey, Long processInstanceKey) {
+    return Objects.equals(rootProcessInstanceKey, processInstanceKey) ?
+        "PI_" + processInstanceKey :
+        "PI_" + rootProcessInstanceKey + "/PI_" + processInstanceKey;
+  }
+
 }
 

data-migrator/core/src/main/java/io/camunda/migration/data/impl/interceptor/history/entity/ProcessInstanceTransformer.java

@@ -44,7 +44,6 @@ public void execute(HistoricProcessInstance entity, ProcessInstanceDbModelBuilde
         .tenantId(getTenantId(entity.getTenantId()))
         .version(entity.getProcessDefinitionVersion())
         .tags(getDefaultTags(entity))
-        .treePath(null)
         .numIncidents(0)
         .partitionId(C7_HISTORY_PARTITION_ID);
   }

data-migrator/qa/integration-tests/src/test/java/io/camunda/migration/data/qa/history/entity/HistoryProcessInstanceTest.java

@@ -172,6 +172,33 @@ public void shouldCheckCalledProcessParentElementKey() {
     assertThat(searchHistoricProcessInstances("calledProcessInstanceId")).isEmpty();
   }
 
+  @Test
+  public void shouldPopulateTreePathForCallActivity() {
+    // given
+    deployer.deployCamunda7Process("callActivityProcess.bpmn");
+    deployer.deployCamunda7Process("calledActivitySubprocess.bpmn");
+    runtimeService.startProcessInstanceByKey("callingProcessId");
+
+    // when
+    historyMigrator.migrate();
+    historyMigrator.setMode(MigratorMode.RETRY_SKIPPED);
+    historyMigrator.migrate();
+
+    // then
+    List<ProcessInstanceEntity> parentProcessInstances = searchHistoricProcessInstances("callingProcessId");
+    List<ProcessInstanceEntity> subProcessInstances = searchHistoricProcessInstances("calledProcessInstanceId");
+    assertThat(parentProcessInstances).hasSize(1);
+    assertThat(subProcessInstances).hasSize(1);
+
+    ProcessInstanceEntity parent = parentProcessInstances.getFirst();
+    ProcessInstanceEntity sub = subProcessInstances.getFirst();
+
+    assertThat(parent.treePath()).isNotNull().isEqualTo("PI_" + parent.processInstanceKey());
+
+    assertThat(sub.treePath()).isNotNull()
+        .isEqualTo("PI_" + parent.processInstanceKey() + "/PI_" + sub.processInstanceKey());
+  }
+
   @Test
   public void shouldPopulateRootProcessInstanceKeyForCallActivity() {
     // given
@@ -197,6 +224,7 @@ public void shouldPopulateRootProcessInstanceKeyForCallActivity() {
     // Sub process should have rootProcessInstanceKey pointing to the parent
     assertThat(sub.rootProcessInstanceKey()).isEqualTo(parent.processInstanceKey());
 
+
     // Verify that flow nodes also have rootProcessInstanceKey
     List<FlowNodeInstanceEntity> subFlowNodes = searchHistoricFlowNodes(sub.processInstanceKey());
     assertThat(subFlowNodes).isNotEmpty();
@@ -310,7 +338,13 @@ protected void verifyProcessInstanceFields(ProcessInstanceEntity processInstance
     }
 
     assertThat(processInstance.hasIncident()).isEqualTo(hasIncidents);
-    assertThat(processInstance.treePath()).isNull();
+
+    assertThat(processInstance.treePath()).isNotNull();
+    if (hasParent) {
+      assertThat(processInstance.treePath()).matches("PI_\\d+/PI_" + processInstance.processInstanceKey());
+    } else {
+      assertThat(processInstance.treePath()).isEqualTo("PI_" + processInstance.processInstanceKey());
+    }
   }
 
   @Test