KO Reactor / KO Undo Manager compatibility (context is not a function)

[silviuburceadev]

I am not sure where this issue belongs/must be fixed, so I'm opening in both repositories, since @bago is KO Reactor contributor and KO Undo Manager author.

According to KO Reactor (link), it supports a context option, which is undocumented. Looking at its usages in assignWatcher function, context should be a function.

However, KO Undo Manager is building an empty object (link) as context and is passing it to KO Reactor (link).

This leads to a TypeError: context is not a function error.

At this point, there are 2 options:

• KO Undo Manager passing an empty function instead of empty object, which is what KO Reactor expects
• KO Reactor checking if context is a function before executing it, e.g. typeof context === 'function' && context(returnValue) instead of context(returnValue).

Additionally, it might help if KO Reactor's context option is documented to indicate how it should look like.

I am happy to contribute with a PR if needed, I'm just not sure what's the correct way to handle this. Both options would be backwards-compatible.

[bago]

I replied to the other issue: bago/knockout-undomanager#5