Crash in enketo-core - TypeError: Cannot read property 'length' of undefined

[kennsippell]

  "info": {
    "stack": "TypeError: Cannot read property 'length' of undefined
    at Object._isNotPrintableKey (https://disc-mali.ml/main.js?_sw-precache=8f55ed87ae50fe146c589063bf3860e3:1:1304311)
    at HTMLFormElement.<anonymous> (https://disc-mali.ml/main.js?_sw-precache=8f55ed87ae50fe146c589063bf3860e3:1:1303639)
    at R.value (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:25487)
    at Object.onInvokeTask (https://disc-mali.ml/main.js?_sw-precache=8f55ed87ae50fe146c589063bf3860e3:1:2387800)
    at R.value (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:25408)
    at R.value (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:19663)
    at R.value [as invoke] (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:27446)
    at W (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:40372)
    at re (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:40764)
    at HTMLFormElement.ue (https://disc-mali.ml/polyfills.js?_sw-precache=c733963449ad3697030f3b3aed9c299e:1:40962)",
    "message": "Cannot read property 'length' of undefined"
  },

The function _isNotPrintableKey from top of stack is (was?) present in enketo-core https://github.com/enketo/enketo-core/blob/827c1f30a62d7e8a9093f7c9b1dac7b2b54151b4/src/js/mask.js#L41

2 instances of this in production moh-mali-chw running cht-core 4.0.1 cc @jkuester

[garethbowen]

It looks like that code was moved in this commit: https://github.com/enketo/enketo-core/commit/fd21204caab56250c70c08de698f82a693480179

Which means essentially the same code still exists in master: https://github.com/enketo/enketo-core/blob/030497118b2fc90a1aed94c2758298ede026147c/src/widget/number-input/number-input.js#L157

I can see some reports that the key is undefined on keydown events on mobile but if that were the case I would expect this error to be much more widespread.

@kennsippell Has anyone been able to reproduce the error? I'm particularly interested in if this is severe (eg: user cannot complete the form) or if it's just generating the feedback doc in the background.

[kennsippell]

Here is some more info about severity:

• This is known from automation-only at this point so we don't know manual steps to reproduce or what the experience looks like for users.
• There are only two known instances of the problem so far. The two datapoints we have are for different users on different days but in the same form
• The form with with the problem is an add contact form. It is the most frequently completed form for these v4.0.1 users.
• This bug doesn't seem blocking. The failing form has been completed ~4000 times by ~19 users on this v4.0.1 instance. For the two specific users with the error - they have both completed it successfully >50 times each.

[garethbowen]

The error looks like a keydown event is being fired without an event.key property (stating the obvious...). This value can be undefined if the key can't be identified: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key

It's possible your e2e test is sending an invalid or unusual key press to the input which the browser doesn't know causing this issue. This would make it less likely but not impossible to reproduce in a real browser.

Enketo core should be updated to protect against this.

[garethbowen]

Issue raised upstream: enketo/enketo#34

[garethbowen]

The upstream issue is fixed and released in enketo-core v7.2.4.

[garethbowen]

Leaving this open until we update enketo-core.

[mrjones-plip]

Enketo has been uplifted and I noted that:

confirm the upgrade fixes the bugs mentioned in cht-core#8102

Closing!