@SteveSandersonMS I've made some changes to centralize the code that determines whether a parameter is an event callback. My approach may have differed slightly from what you had in mind, so let me know if you would prefer it be done in a different way.

The biggest change I made to get this to work was providing component parameter info to JS in enableJSRootComponents regardless of whether an initializer was provided. This allows DynamicRootComponent to determine if a parameter is of type eventcallback from the decision made earlier in .NET. This required some minor refactoring on the JS side and slightly more on the .NET side.

This is looking really good to me!

My approach may have differed slightly from what you had in mind, so let me know if you would prefer it be done in a different way.

No, looks solid.

The biggest change I made to get this to work was providing component parameter info to JS in enableJSRootComponents regardless of whether an initializer was provided.

I admit I hadn't thought through that particular consequence, but it doesn't seem problematic and the way you've implemented it is clear. Thinking about it more, the previous "optimization" about not supplying parameter infos when there was no initializer would only take effect in really edge-case scenarios, and it would probably be inevitable in the long run that we'd have reasons to pass through parameter infos for whatever future functionality we end up building in this area. So in retrospect I don't think there was much of a good reason to be trying to skip passing that info, and what you have done here is clearer than we had before.

@SteveSandersonMS Thanks for the feedback! I've just updated the implementation to support the parameter reassignment scenarios (including setting parameters to null). The new approach also doesn't mutate the parameters argument and instead creates a copy.