"JSON.stringify cannot serialize cyclic structures." when tapping Enter in the More block

[hypest]

There seems to be an issue with tapping an enter at the end of the more block.

The desired behavior is to just create a new (paragraph) block after the more when "Enter" is inputted.

Steps to reproduce:

1. Open the demo app (android or iOS)
2. Tap into the "Read more" block. The cursor should be at the end of the "Read more"
3. Tap "enter" on the virtual keyboard.
4. 💥

JSON.stringify cannot serialize cyclic structures.
serializeAttributes
    serializer.js:181:24
getCommentDelimitedContent
    serializer.js:233:23
serializeBlock
    serializer.js:274:38
serialize
    serializer.js:286:33
<unknown>
    selectors.js:1684:29
callSelector
    rememo.js:249:24
<unknown>
    namespace-store.js:106:60
<unknown>
    AppContainer.js:139:42
getNextMergeProps
    index.js:42:21
onStoreChange
    index.js:122:45
<unknown>
    registry.js:49:45
globalListener
    registry.js:49:21
<unknown>
    namespace-store.js:57:12
dispatch
    createStore.js:186:14
<unknown>
    promise-middleware.js:20:14
<unknown>
    resolvers-cache-middleware.js:33:7
<unknown>
    refx.js:26:20
<unknown>
    namespace-store.js:118:72
proxyDispatch
    index.js:42:4
onChange
    AppContainer.js:54:33
setAttributes
    block-holder.js:58:26
onChange
    edit.native.js:32:47
_onChange
    TextInput.js:1119:47
invokeGuardedCallbackImpl
    ReactNativeRenderer-dev.js:93:15
invokeGuardedCallback
    ReactNativeRenderer-dev.js:318:36
invokeGuardedCallbackAndCatchFirstError
    ReactNativeRenderer-dev.js:342:30
executeDispatch
    ReactNativeRenderer-dev.js:715:42
executeDispatchesInOrder
    ReactNativeRenderer-dev.js:737:20
executeDispatchesAndRelease
    ReactNativeRenderer-dev.js:894:29
forEachAccumulated
    ReactNativeRenderer-dev.js:876:12
runEventsInBatch
    ReactNativeRenderer-dev.js:1050:21
runExtractedEventsInBatch
    ReactNativeRenderer-dev.js:1072:19
<unknown>
    ReactNativeRenderer-dev.js:2711:6
batchedUpdates$1
    ReactNativeRenderer-dev.js:17075:14
batchedUpdates
    ReactNativeRenderer-dev.js:2614:31
_receiveRootNodeIDEvent
    ReactNativeRenderer-dev.js:2709:17
receiveEvent
    ReactNativeRenderer-dev.js:2729:26
__callFunction
    MessageQueue.js:349:47
<unknown>
    MessageQueue.js:106:26
__guard
    MessageQueue.js:297:10
callFunctionReturnFlushedQueue
    MessageQueue.js:105:17

[daniloercoli]

I can replicate the issue by inserting any character in the More block. At any position in the text.

• Open the demo app (tested on Android only)
• Tap into the "Read more" block. Place the caret at the middle of "Read more"
• Tap any character on the virtual keyboard.
• Booom

[daniloercoli]

In order to see what was received from the underlying layers, I changed the onChange prop in More block by doing this onChange={ ( newValue ) => console.log( newValue ) } and noticed that the app is not crashing anymore, you can write any characters in the More block, but:

• The log is never printed in AS console
• If you try to move the caret to another block, it will be brought back into the More block
• The app becomes laggy, and it crashes after a while with no info logged in console

I then thought it was a problem in the JSON.stringify() method that is called over newValue to print it in console, and than changed it to onChange={ ( ) => console.log( 'Hello!' ) }, to see if i was able to print something in console onChange but the problem is the same of above. Nothing is printed and the app crashes after a while.

Edit:
After more investigation it seems the correct value is returned from TextInput->PlainText till to the More block. Then the problem happens when we update with setAttributes, even though the correct value is passed. cc @Tug

[daniloercoli]

I also noticed that the Enter.key handling/detection is not implemented in the More Block.
Actually I don't think we've the Enter.key detection in place on PlainText based blocks. We should probably open a new ticket for it. Assigning it to beta? cc @hypest

[hypest]

We should probably open a new ticket for it. Assigning it to beta?

Let's indeed create a new ticket but let's add it to the Alpha. If we can't make it we can bump it to the Beta.