Some Strange Behavior after initial setup

[allain]

Following along with instructions when the app runs I see:

1. Adding event causes 2 events to appear for half a second then it disappears
2. Commenting causes 2 comments to appear (only 1 is actually created in DynamoDB), and then after 2 seconds or so the entire event screen clears out and becomes a single "Back to Events" button.
3. Clicking on the button takes me back to the events listing but no event is displayed
4. Clicking the browser's Refresh Button makes the event appear again.
5. Attempting to add another comment cause the error below to be thrown:

Uncaught TypeError: Cannot read property 'comments' of undefined
at Object.props (EventComments.js:63)

If it helps I'm running npm start in node v8.9.1 and my browser is "Version 64.0.3282.167 (Official Build) Built on Ubuntu , running on LinuxMint 18.2 (64-bit)"

Thanks

[manueliglesias]

Hi @allain

Thanks for trying this sample! Could you please check if you get the same behavior after deleting your node_modules and re install using yarn?

[allain]

Thanks for responding.

Using yarn 1.5.1 on first run I'm getting:

./node_modules/react-apollo/react-apollo.browser.umd.js
Module not found: Can't resolve 'apollo-client' in '/home/allain/fq/aws-mobile-appsync-events-starter-react/node_modules/react-apollo'

Unfortunately after yarn add apollo-client it runs but the problems in the issue still persist.

[ozby]

i am also encountering same issues

[vmtzkr]

I am also experiencing this problem. Would be great, if it would be fixed quickly.

[manueliglesias]

Hey, can you guys try again with the recently added yarn.lock ?

Feel free to re-open if needed

[vmtzkr]

I just tried the new yarn file and some sources point to localhost. Shouldn't be right?
error An unexpected error occurred: "http://localhost:4873/aws-appsync/-/aws-appsync-1.0.12.tgz: connect ECONNREFUSED 127.0.0.1:4873".

[allain]

same error here

[elorzafe]

Hi @allain and @vilius-rugaitis I have updated both lock files.

Please let me know how it goes

[erezrokah]

I'm having the same issue with latest code from master (duplicates events and comments).
I had the Uncaught TypeError: Cannot read property 'comments' of undefined at Object.props (EventComments.js:63) error as well but can't reproduce at the moment.

I'm pretty new to apollo, GraphQL and the optimistic response mechanism, but shouldn't setting an id on the client (using uuid), updating the cache based on that id, then updating again based on the response from the server (which auto generates a different id) might cause the duplication?

Regarding the Uncaught TypeError: it seems like a timing issue where the data is set to an empty object for a brief moment.
If react happens to perform a render cycle while the data object is empty you get that error.
I haven't been able to figure out the reason for that yet.

[elorzafe]

Hi @erezrokah did you use yarn or npm install?

[erezrokah]

@elorzafe I tried both (removed node_modules before each time).
Currently using yarn install.
Also cleared the browser cache.
It is more evident once you have more than 3 events or so.

Edit:
found this:
https://stackoverflow.com/questions/49118378/apollo-mutate-calling-update-four-times-for-a-single-mutation

Maybe it can explain the duplication.

Another edit:
I have a possible fix in this branch:
https://github.com/Noless/aws-mobile-appsync-events-starter-react/tree/duplicate_events_comments_fix

I'm still testing (I still have a duplicate keys issue with the comments subscription), but it might serve as a workaround.

Another edit. Opened #16

[burmisov]

Same bug here after precisely following all the instructions

[erezrokah]

@elorzafe can we get an update regarding this issue?