TSK-1115: Validate that Service Level is not negative (#1454)

lib/taskana-core/src/main/java/pro/taskana/classification/internal/ClassificationServiceImpl.java

@@ -315,9 +315,10 @@ public class ClassificationServiceImpl implements ClassificationService {
   }
 
   private static void validateServiceLevel(String serviceLevel) throws InvalidArgumentException {
-    try {
+    Duration duration;
-      Duration.parse(serviceLevel);
 
+    try {
+      duration = Duration.parse(serviceLevel);
     } catch (Exception e) {
       throw new InvalidArgumentException(
           String.format(
@@ -328,10 +329,16 @@ public class ClassificationServiceImpl implements ClassificationService {
               serviceLevel),
           e.getCause());
     }
-    // check that the duration is based on format PnD, i.e. it must start with a P, end with a D
-    String serviceLevelLower = serviceLevel.toLowerCase();
-    if (!serviceLevelLower.startsWith("p") || !serviceLevelLower.endsWith("d")) {
 
+    if (duration.isNegative()) {
+      throw new InvalidArgumentException(
+          String.format(
+              "Invalid service level %s. Taskana does not support a negative service level.",
+              serviceLevel));
+    }
+
+    // check that the duration is based on format PnD, i.e. it must start with a P, end with a D
+    if (!serviceLevel.toLowerCase().startsWith("p") || !serviceLevel.toLowerCase().endsWith("d")) {
       throw new InvalidArgumentException(
           String.format(
               "Invalid service level %s. Taskana only supports service "

lib/taskana-core/src/test/java/acceptance/classification/CreateClassificationAccTest.java

@@ -165,6 +165,17 @@ class CreateClassificationAccTest extends AbstractAccTest {
         .isInstanceOf(InvalidArgumentException.class);
   }
 
+  @WithAccessId(user = "businessadmin")
+  @Test
+  void should_ThrowException_When_TryingToCreateClassificationWithNegativeServiceLevel() {
+    Classification classification =
+        CLASSIFICATION_SERVICE.newClassification("someKey234", "DOMAIN_A", "TASK");
+    classification.setServiceLevel("P-1D");
+
+    assertThatThrownBy(() -> CLASSIFICATION_SERVICE.createClassification(classification))
+        .isInstanceOf(InvalidArgumentException.class);
+  }
+
   @WithAccessId(user = "businessadmin")
   @Test
   void testCreateClassificationWithInvalidValues() {