The string undefined seems to be passed for some errors which we can't do much about:
https://logstash.wikimedia.org/app/kibana#/doc/logstash-*/logstash-2020.09.25/clienterror?id=AXTHTpsD66Rhvr6TP6Yo&_g=h@991ce06
eg.
t _type clienterror t error_class t file_url undefined ``
| Status | Subtype | Assigned | Task | ||
|---|---|---|---|---|---|
| Open | None | T49145 Formally deprecate jQuery UI after we've stopped using jQuery UI in extensions and core | |||
| Open | None | T100270 Replace use of jQuery UI and MW UI with OOUI across all Wikimedia-deployed extensions and core | |||
| Open | None | T85394 Use OOUI suggestions/autocompletion components only (instead of jquery.suggestions, jquery.ui.autocomplete) | |||
| Open | None | T125725 [epic] Update autocomplete search box with metadata and remove and delete the old searchSuggest system | |||
| Open | None | T177251 Dead keys prevent autocomplete in search box | |||
| Resolved | ovasileva | T244392 [GOAL] Deploy the new Vue.js search experience | |||
| Resolved | ovasileva | T275200 Analyze results of A/B test for new search widget | |||
| Resolved | ovasileva | T249297 Deploy the new Vue.js search experience | |||
| Resolved | • jlinehan | T255585 [EPIC] Extend client-side error logging coverage to include English Wikipedia | |||
| Declined | None | T263898 Filter out errors with file_url "undefined" |
Change 634295 had a related patch set uploaded (by Jdlrobson; owner: Jason Linehan):
[mediawiki/extensions/WikimediaEvents@master] clientError: Adds new fields and updates behavior.
On second thoughts, given we can filter out undefined, I suggest explicitly rewriting any empty strings to undefined and declining this task.