Being able to receive warnings in custom handlers

[eirslett]

An example would be when using jquery-migrate in unit tests:

jQuery.migrateWarningHandler(warning => failTheUnitTest(warning))

or one could throw an exception possibly.

Migrate warnings would then fail the build, so problems are discovered early.

See This PR in jquery-ui for context.

(Ideally it would be possible to use both in 1.4.x and 3.x, since that is what jquery-ui uses)

[dmethvin]

See #15 and #196 for some approaches on this. I think they solve that use case? You can also patch console.warn and fail the test if you see JQMIGRATE in the message.

[eirslett]

I cannot find issue #296 (in the jquery-migrate project), which one is that?
Yes, one could simply monkey-patch console.warn or jQuery.migrateWarnings.push, but I'm not sure it's a good idea - it relies on undocumented internal implementation details of jquery-migrate, which could be changed at any time. It would imply a strict requirement on jquery-migrate to never change its internal implementations.

[dmethvin]

Sorry I meant #196. I don't expect we'll change those details since we've advocated their use in several tickets at this point. If you'd like to use it and add a comment to that effect please file a PR.

Adding a handler interface is always more complicated that you might think, it needs to define what happens for multiple listeners and there's the possibility of recursion (e.g., a warning handler calling a jQuery method that itself generates a warning). Yes all of those things can be defined, guarded, or documented away but given the small number of use cases I think we have acceptable solutions already.

[eirslett]

Ok, thank you for your responses! I will try to monkey-patch jQuery.migrateWarnings.push then.