Add test to validate Issues 238

src/test/groovy/com/lesfurets/jenkins/unit/declarative/TestDeclarativePipeline.groovy

@@ -213,6 +213,12 @@ class TestDeclarativePipeline extends DeclarativePipelineTest {
         assertJobStatusSuccess()
     }
 
+    @Test void should_parallel_nested_stages() throws Exception {
+        runScript('Parallel_NestedStages_Jenkinsfile')
+        printCallStack()
+        assertJobStatusSuccess()
+    }
+
     @Test void should_sub_stages() throws Exception {
         runScript('ComplexStages_Jenkinsfile')
         printCallStack()

src/test/jenkins/jenkinsfiles/Parallel_NestedStages_Jenkinsfile

@@ -0,0 +1,17 @@
+pipeline {
+    stages {
+        stage('Parallel Stage') {
+            parallel {
+                stage('Branch A') {
+                    stages {
+                        stage('Nested 1') {
+                            steps {
+                                echo "In stage Nested 1 within Branch A"
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}