Error During Done Function on a Promise Is Skipped on Subsequent Runs

[jrduncans]

Having an error in a .done() callback function seems to permanently break the state of a Deferred, in a way that success does not. The documentation of Deferred does not cover error handling within callbacks, so it's not clear if this is by design or not.

Demo: ​http://jsfiddle.net/2JFnM/

[sindresorhus]

I think the consensus is that you should handle your own exceptions. jQuery should not hide it away.

See the duplicates for more info and discussion.

Duplicates: #11207, #11193, #9033

Leaving it open so that it can be documented.

[dmethvin]

Dean Edwards documented a way of using synthetic events as callbacks to prevent this problem, but I don't know if it can be applied. The use of a propertychange handler on documentElement seems like it might pose some performance problems.

​http://dean.edwards.name/weblog/2009/03/callbacks-vs-events/

Let's explore for 1.8 and decide whether it can be fixed or if we should just document current behavior.

[jaubourg]

Eveything is said here: ​http://bugs.jquery.com/ticket/11193#comment:3

In an ideal world, we'd be able to use try/finally but, because of IE, we can't.

[dmethvin]

This can be fixed eventually, but not until oldIE bites the dust.