Fix duplicate events and comments

src/App.js

@@ -36,7 +36,8 @@ const client = new AWSAppSyncClient({
   auth: {
     type: appSyncConfig.authenticationType,
     apiKey: appSyncConfig.apiKey,
-  }
+  },
+  disableOffline: true
 });
 
 const WithProvider = () => (

src/Components/AllEvents.js

@@ -86,7 +86,10 @@ export default compose(
                     const query = QueryAllEvents;
                     const data = proxy.readQuery({ query });
 
-                    data.listEvents.items = data.listEvents.items.filter(event => event.id !== deleteEvent.id);
+                    const index = data.listEvents.items.findIndex(event => event.id === deleteEvent.id)
+                    if (index > -1) {
+                        data.listEvents.items.splice(index, 1)
+                    }
 
                     proxy.writeQuery({ query, data });
                 }

src/Components/EventComments.js

@@ -67,6 +67,12 @@ const EventCommentsWithData = graphql(
                     eventId: props.ownProps.eventId,
                 },
                 updateQuery: (prev, { subscriptionData: { data: { subscribeToEventComments } } }) => {
+                    //skip the update if the comment exists.
+                    //This can happen when the `createComment` Mutation updates the query
+                    if (prev.getEvent.comments.items.some(c => c.commentId === subscribeToEventComments.commentId)) {
+                        return prev;
+                    }
+
                     const res = {
                         ...prev,
                         ...{
@@ -75,13 +81,7 @@ const EventCommentsWithData = graphql(
                                 comments: {
                                     __typename: 'CommentConnections',
                                     items: [
-                                        ...prev.getEvent.comments.items.filter(c => {
-                                            return (
-                                                c.content !== subscribeToEventComments.content &&
-                                                c.createdAt !== subscribeToEventComments.createdAt &&
-                                                c.commentId !== subscribeToEventComments.commentId
-                                            );
-                                        }),
+                                        ...prev.getEvent.comments.items,
                                         subscribeToEventComments,
                                     ]
                                 }

src/Components/NewComment.js

@@ -68,16 +68,10 @@ const NewCommentWithData = graphql(
                 const variables = { id: props.eventId };
                 const data = proxy.readQuery({ query, variables });
 
-                data.getEvent = {
-                    ...data.getEvent,
-                    comments: {
-                        ...data.getEvent.comments,
-                        items: [
-                            ...data.getEvent.comments.items.filter(c => c.commentId !== commentOnEvent.commentId),
-                            commentOnEvent,
-                        ]
-                    }
-                };
+                //don't add an existing comment (can happen when the comments subscription updates the query)
+                if (!data.getEvent.comments.items.some(c => c.commentId === commentOnEvent.commentId)) {
+                    data.getEvent.comments.items.push(commentOnEvent);
+                }
 
                 proxy.writeQuery({ query, data });
             },

src/Components/NewEvent.js

@@ -110,7 +110,7 @@ export default graphql(
                 const query = QueryAllEvents;
                 const data = proxy.readQuery({ query });
 
-                data.listEvents.items = [...data.listEvents.items.filter(e => e.id !== createEvent.id), createEvent];
+                data.listEvents.items.push(createEvent);
 
                 proxy.writeQuery({ query, data });
             }