Allow removing default middleware in Bolt

[luispollo]

Firstly, thank you for building this SDK -- it's awesome!

Currently, you can call the use method to register middleware on the App class, but you cannot modify the list. For example, in my case I wanted to remove the RequestVerification middleware because we have a proxy in front of our server that already checks the Slack signatures, but I was forced to sub-class App in order to override buildDefaultMiddlewareList to filter out that middleware.

It'd be nice if there was a way to modify the middleware list outside of App's constructor, or perhaps just expose buildDefaultMiddlewareList as a public static method, so you could do something like this:

val middleware = App.buildDefaultMiddlewareList().filter { it !is RequestVerification }
val app = App(appConfig, middleware)

Alternatively, for my particular use case, a configuration flag in AppConfig controlling whether that specific middleware gets included in the list would have done the trick as well.

Cc: @gal-yardeni

Category (place an x in each of the [ ])

• bolt (Bolt for Java)
• bolt-{sub modules} (Bolt for Java - optional modules)
• slack-api-client (Slack API Clients)
• slack-api-model (Slack API Data Models)
• slack-api-*-kotlin-extension (Kotlin Extensions for Slack API Clients)
• slack-app-backend (The primitive layer of Bolt for Java)

[seratch]

👋 Hi @luispollo, thanks for using Bolt for Java! We are happy to enhance this SDK to meet your needs.

Alternatively, for my particular use case, a configuration flag in AppConfig controlling whether that specific middleware gets included in the list would have done the trick as well.

I'm down to go with this idea. I'll work on the change and release a new version including it shortly.