Breaking change to the data module in 3.5.0

[rjaros]

The change to the data module made here:

https://github.com/jquery/jquery/pull/4603/files#diff-38fa4ad21a97c2bf8d5b91d033df3335

breaks projects that depend on hasOwnProperty() function availability.

An example: snapappointments/bootstrap-select#2430
Many other project can be affected as well.

Such change should not be introduced as a minor version upgrade.

[mgol]

Thanks for the report. I agree this is an unintended breaking change that we should fix in 3.5.1. Marking for team discussion.

Perhaps we can leave the current solution for jQuery 4.0.0 and in 3.5.1 apply original @gibson042’s suggestion of appending a space to event names before storing in the internal data storage. This solution can break code that relied on the private jQuery._data API to have real event names as event keys without any space at the end but since it’s a private API, this looks more acceptable to me.

Some possible consumer are web browsers, I think Firefox is using this API for jQuery event support in DevTools. If that’s still the case, do you know, @bzbarsky, who at Mozilla we could contact to coordinate any changes to this API?

[rjaros]

Any chance on quick 3.5.1 release?

[mgol]

@rjaros our release process is pretty involved and we still need to discuss & iron out the fix. Don’t expect it within days, more like a few weeks.

[mgol]

We’ll monitor the situation. If we get info about many more projects broken by this change, we’ll try to get the fix out quicker. No promises about specific timing, though: it’s Easter and we’re all volunteers.

[XhmikosR]

@mgol it seems we are affected by the aforementioned change too: twbs/bootstrap#30553

Should I open another issue?

[mgol]

@XhmikosR no, let’s track all similar bugs in this issue.

[XhmikosR]

So, basically the failures can be seen here where I updated jQuery to v3.5.0 and adapted our tests: CI errors

The code is quite old, since our v3.3.4.

[the-hotmann]

Indeed this is also affecting our system (InvoicePlane), jQuery 3.5.0 is tiggering many erros and also breaking the whole JS functonality. Indeed braking changes should not be implemented in a normal release, but instead in a mainrelease (^4.0.0) in jQuery as this will automatically break all projects which are based on jQuery and trust it to not include breaking changes within the same mainversion.

Also we had to change our package.json to not update to jQuery 3.5.0 and stay on ~3.4.1 for not running into this issue.

For us the eror was:
jQuery.Deferred exception: e.hasOwnProperty is not a function TypeError: e.hasOwnProperty is not a function