josdejong/jsoneditor

"Cannot read properties of null (reading 'getInternalPath')"

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#1.498 geöffnet am 16. Feb. 2023

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bughelp wanted

Beschreibung

I'm sporadically getting the following error when I change object keys (not values):

TypeError: Cannot read properties of null (reading 'getInternalPath')
S.value
https://76uwry.csb.app/node_modules/jsoneditor/dist/jsoneditor.min.js:33:36942
eval
https://76uwry.csb.app/node_modules/jsoneditor/dist/jsoneditor.min.js:35:2194

See https://codesandbox.io/s/jsoneditor-debounced-error-76uwry for an example: Try changing hello. (This calls setValue extremely fast to demonstrate the problem.)

I believe that the problem is caused by a race condition: Edits are propagated with a 150ms delay (due to the use of debounce), so, if the editor receives a new value, the old value has been removed and no longer has the fields that the event handler expects it to have.

https://github.com/josdejong/jsoneditor/blob/v9.9.2/src/js/Node.js#L1649

I'm not sure if the correct fix is to cancel debounced events when a node is removed (e.g., Lodash's debounce has a cancel function; a similar idea could be added here) or make the events check for, e.g., this.parent == null.

Contributor Guide

Tech Stack
javascriptnodejs
Domain
frontend
Issue Type
bug
SchwierigkeitGeschätzte Implementierungsschwierigkeit für neue Contributors, von 1 für sehr kleine Änderungen bis 5 für Expertenarbeit.
2
Geschätzte ZeitEin grober Zeitrahmen, um zu recherchieren, zu implementieren, zu testen und einen Pull Request vorzubereiten.
1-3 hours
AktivitätsstatusWie verfügbar das Issue gerade wirkt: frisch, aktiv, stale, blockiert oder wartet auf Maintainer-Input.
fresh
KlarheitWie klar das Issue die erwartete Änderung, Akzeptanzkriterien und den nächsten Schritt erklärt.
mostly clear
Voraussetzungen
Understanding of JavaScriptKnowledge of debounce
EinsteigerfreundlichkeitEin Score von 1 bis 100, der schätzt, wie zugänglich dieses Issue für First-Time Contributors ist.
50
Research-Richtung
Investigate the race condition in the debounced event propagation. Look at the source file src/js/Node.js, specifically line 1649. Consider either adding a method to cancel debounced events when a node is removed (similar to Lodash's debounce.cancel) or adding a null check for this.parent. Check the linked CodeSandbox for reproduction.