added Tests and fix addUserEvent

src/main/java/mops/gruppen2/domain/Group.java

@@ -52,8 +52,10 @@ public class Group extends Aggregate {
     private void applyEvent(AddUserEvent event) {
         User user = new User(event.getUser_id(), event.getGivenname(), event.getFamilyname(), event.getEmail());
 
+        if (!this.members.contains(user)){
             this.members.add(user);
         }
+    }
 
     private void applyEvent(UpdateGroupTitleEvent event) {
         this.title = event.getNewGroupTitle();

src/main/java/mops/gruppen2/domain/User.java

@@ -2,12 +2,16 @@ package mops.gruppen2.domain;
 
 import lombok.AllArgsConstructor;
 import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.Value;
 
-@Data
+@Value
 @AllArgsConstructor
+@EqualsAndHashCode(exclude = {"givenname", "familyname", "email"})
 public class User {
 
     String user_id;
+
     String givenname;
     String familyname;
     String email;

src/test/java/mops/gruppen2/domain/GroupTest.java

@@ -2,6 +2,7 @@ package mops.gruppen2.domain;
 
 import mops.gruppen2.domain.event.AddUserEvent;
 import mops.gruppen2.domain.event.CreateGroupEvent;
+import mops.gruppen2.domain.event.DeleteUserEvent;
 import mops.gruppen2.domain.event.UpdateRoleEvent;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
@@ -47,6 +48,38 @@ class GroupTest {
         assertThat(group.getMembers().get(0)).isEqualTo(user);
     }
 
+    @Test
+    void addExistingUser() {
+        CreateGroupEvent createGroupEvent = new CreateGroupEvent(1,1,"prof1", "hi", "foo");
+        Group group = new Group();
+        group.applyEvent(createGroupEvent);
+
+        User user1 = new User("prof", "jens", "bendi", "hi@gmail.com");
+        AddUserEvent addUserEvent1 = new AddUserEvent(2,1, user1);
+        group.applyEvent(addUserEvent1);
+
+        User user2 = new User("prof", "olga", "bendi", "hi@gmail.com");
+        AddUserEvent addUserEvent2 = new AddUserEvent(3,1, user2);
+        group.applyEvent(addUserEvent2);
+
+        assertThat(group.getMembers().size()).isEqualTo(1);
+    }
+
+    @Test
+    void deleteSingleUser() {
+        CreateGroupEvent createGroupEvent = new CreateGroupEvent(1, 2, "Prof", "Tolle Gruppe", "Tolle Beshreibung");
+        User user = new User("Prof", "Pro", "fessor", "pro@fessor.de");
+        AddUserEvent addUserEvent = new AddUserEvent(2, 2, user);
+        Group group = new Group();
+        group.applyEvent(createGroupEvent);
+        group.applyEvent(addUserEvent);
+
+        DeleteUserEvent deleteUserEvent = new DeleteUserEvent(3, 2, "Prof");
+        group.applyEvent(deleteUserEvent);
+
+        assertThat(group.getMembers().size()).isEqualTo(0);
+    }
+
     // Verwendet CreateGroupEvent und AddUserEvent
     @Test
     void updateRoleForExistingUser() {