adjust sorting to be consistent

module-audited-entity/pom.xml

@@ -33,7 +33,7 @@
 
     <dependencies>
 
-        
+
         <dependency>
             <groupId>${project.groupId}</groupId>
             <artifactId>nexus-security-module</artifactId>
@@ -58,6 +58,12 @@
 
         <!-- TESTS -->
 
+        <dependency>
+            <groupId>org.apache.causeway.testing</groupId>
+            <artifactId>causeway-testing-unittestsupport-applib</artifactId>
+            <scope>test</scope>
+        </dependency>
+
 
         <!-- IDE support (optional) -->
         <dependency>

module-audited-entity/src/main/java/net/savantly/nexus/audited/api/AuditedEntitySortedByDateDesc.java

@@ -6,9 +6,20 @@ public class AuditedEntitySortedByDateDesc implements Comparator<AuditedEntity>
 
     @Override
     public int compare(AuditedEntity o1, AuditedEntity o2) {
-        if (o1.getCreatedDate() == null || o2.getCreatedDate() == null) {
+
+        // sort with nulls last
+        if (o1.getCreatedDate() == null && o2.getCreatedDate() == null) {
             return 0;
         }
+
+        if (o1.getCreatedDate() == null) {
+            return 1;
+        }
+
+        if (o2.getCreatedDate() == null) {
+            return -1;
+        }
+
         return o2.getCreatedDate().compareTo(o1.getCreatedDate());
     }
 }

module-audited-entity/src/test/java/net/savantly/nexus/audited/api/AuditedEntitySortedByDateDesc_test.java

@@ -0,0 +1,81 @@
+package net.savantly.nexus.audited.api;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.ZonedDateTime;
+
+import org.junit.jupiter.api.Test;
+
+public class AuditedEntitySortedByDateDesc_test {
+
+    @Test
+    public void testCompare() {
+        // given
+        AuditedEntitySortedByDateDesc comparator = new AuditedEntitySortedByDateDesc();
+        AuditedEntity o1 = new MockAuditedEntity();
+        AuditedEntity o2 = new MockAuditedEntity();
+        o1.setCreatedDate(ZonedDateTime.now().minusDays(1));
+        o2.setCreatedDate(ZonedDateTime.now());
+
+        // when
+        int result = comparator.compare(o1, o2);
+
+        // then
+        assertThat(result).isPositive();
+
+    }
+
+    @Test
+    public void testCompareWithNulls() {
+        // given
+        AuditedEntitySortedByDateDesc comparator = new AuditedEntitySortedByDateDesc();
+        AuditedEntity o1 = new MockAuditedEntity();
+        AuditedEntity o2 = new MockAuditedEntity();
+        o1.setCreatedDate(ZonedDateTime.now().minusDays(1));
+        o2.setCreatedDate(null);
+
+        // when
+        int result = comparator.compare(o1, o2);
+
+        // then
+        assertThat(result).isNegative();
+
+    }
+
+    @Test
+    public void testCompareWithNullsBoth() {
+        // given
+        AuditedEntitySortedByDateDesc comparator = new AuditedEntitySortedByDateDesc();
+        AuditedEntity o1 = new MockAuditedEntity();
+        AuditedEntity o2 = new MockAuditedEntity();
+        o1.setCreatedDate(null);
+        o2.setCreatedDate(null);
+
+        // when
+        int result = comparator.compare(o1, o2);
+
+        // then
+        assertThat(result).isZero();
+
+    }
+
+    @Test
+    public void testCompareWithNullsFirst() {
+        // given
+        AuditedEntitySortedByDateDesc comparator = new AuditedEntitySortedByDateDesc();
+        AuditedEntity o1 = new MockAuditedEntity();
+        AuditedEntity o2 = new MockAuditedEntity();
+        o1.setCreatedDate(null);
+        o2.setCreatedDate(ZonedDateTime.now().minusDays(1));
+
+        // when
+        int result = comparator.compare(o1, o2);
+
+        // then
+        assertThat(result).isPositive();
+
+    }
+
+    static class MockAuditedEntity extends AuditedEntity {
+    }
+}