Fix event participation

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/views/Event/Event.vue

@@ -1010,20 +1010,25 @@ export default class Event extends EventMixin {
             query: EVENT_PERSON_PARTICIPATION,
             variables: { eventId: this.event.id, actorId: identity.id },
           });
-          if (participationCachedData == null) return;
-          const { person } = participationCachedData;
-          if (person === null) {
+
+          if (participationCachedData?.person == undefined) {
             console.error(
               "Cannot update participation cache, because of null value."
             );
             return;
           }
-          person.participations.elements.push(data.joinEvent);
-          person.participations.total += 1;
           store.writeQuery({
             query: EVENT_PERSON_PARTICIPATION,
             variables: { eventId: this.event.id, actorId: identity.id },
-            data: { person },
+            data: {
+              person: {
+                ...participationCachedData?.person,
+                participations: {
+                  elements: [data.joinEvent],
+                  total: 1,
+                },
+              },
+            },
           });
 
           const cachedData = store.readQuery<{ event: IEvent }>({
@@ -1038,18 +1043,24 @@ export default class Event extends EventMixin {
             );
             return;
           }
+          const participantStats = { ...event.participantStats };
 
           if (data.joinEvent.role === ParticipantRole.NOT_APPROVED) {
-            event.participantStats.notApproved += 1;
+            participantStats.notApproved += 1;
           } else {
-            event.participantStats.going += 1;
-            event.participantStats.participant += 1;
+            participantStats.going += 1;
+            participantStats.participant += 1;
           }
 
           store.writeQuery({
             query: FETCH_EVENT,
             variables: { uuid: this.uuid },
-            data: { event },
+            data: {
+              event: {
+                ...event,
+                participantStats,
+              },
+            },
           });
         },
       });