josdejong/jsoneditor

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

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#1 498 ouverte le 16 févr. 2023

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 (3 commentaires) (0 réactions) (0 assignés)JavaScript (10 781 stars) (2 034 forks)batch import
bughelp wanted

Description

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.

Guide contributeur

Stack technique
javascriptnodejs
Domaine
frontend
Type d'issue
bug
DifficultéDifficulté estimée pour un nouveau contributeur, de 1 pour un très petit changement à 5 pour un travail expert.
2
Temps estiméFourchette de temps approximative pour investiguer, implémenter, tester et préparer une pull request.
1-3 hours
Statut d'activitéDisponibilité apparente de l'issue : fraîche, active, ancienne, bloquée ou en attente d'un mainteneur.
fresh
ClartéClarté avec laquelle l'issue explique le changement attendu, les critères d'acceptation et la prochaine étape.
mostly clear
Prérequis
Understanding of JavaScriptKnowledge of debounce
Accessibilité débutantScore de 1 à 100 estimant l'accessibilité de cette issue pour un premier contributeur.
50
Direction de recherche
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.