Port Action based Messaging Extensions (fetch task) to JS

[Virtual-Josh]

Copy the C# scenario to JS

https://github.com/microsoft/botbuilder-dotnet/tree/master/tests/Teams/ActionBasedMessagingExtension-FetchTask

[daveta]

I'm doing this in preview

[johnataylor]

This is related to a change we want to make in the SendToChannel the code should look more like this:

https://docs.microsoft.com/en-us/microsoftteams/platform/concepts/bots/bot-conversations/bots-conv-proactive#creating-a-channel-conversation

In other words the send to channel should - depending on scenario - call CreateConversation
when you do that you are in the proactive scenario - and code such as ContinueConversation applies.

[daveta]

PR in, waiting for feedback..