Deprecate FeatureMessage, FeatureMessageReceiver, and related legacy bus types

Author: maxep

DatadogInternal/Sources/DatadogFeature.swift

@@ -15,6 +15,7 @@ public protocol DatadogFeature {
     ///
     /// The `FeatureMessageReceiver` defines an interface for Feature to receive any message
     /// from a bus that is shared between Features registered in a core.
+    @available(*, deprecated, message: "Use `BusMessageReceiver` and subscribe via `MessageBus` instead.")
     var messageReceiver: FeatureMessageReceiver { get }
 }
 

DatadogInternal/Sources/MessageBus/FeatureMessage.swift

@@ -7,6 +7,7 @@
 import Foundation
 
 /// The set of messages that can be transmitted on the Features message bus.
+@available(*, deprecated, message: "Use `BusMessage` and `MessageBus` for typed feature-to-feature messaging.")
 public enum FeatureMessage {
     /// A custom payload message.
     case payload(Any)

DatadogInternal/Sources/MessageBus/FeatureMessageReceiver.swift

@@ -11,6 +11,7 @@ import Foundation
 ///
 /// The message is composed of a key and a dictionary of attributes. The message format is a loose
 /// agreement between Features - all messages supported by a Feature should be properly documented.
+@available(*, deprecated, message: "Use `BusMessageReceiver` for typed feature-to-feature messaging.")
 public protocol FeatureMessageReceiver {
     /// Receives messages from the message bus.
     ///
@@ -32,6 +33,7 @@ public protocol FeatureMessageReceiver {
     // instead of depending on directly on `core`.
 }
 
+@available(*, deprecated, message: "Use `BusMessageReceiver` for typed feature-to-feature messaging.")
 public struct NOPFeatureMessageReceiver: FeatureMessageReceiver {
     public init() { }
 
@@ -43,6 +45,7 @@ public struct NOPFeatureMessageReceiver: FeatureMessageReceiver {
 
 /// A receiver that combines multiple receivers. It will loop though receivers and stop on the first that is able to
 /// consume the given message.
+@available(*, deprecated, message: "Use `BusMessageReceiver` for typed feature-to-feature messaging.")
 public struct CombinedFeatureMessageReceiver: FeatureMessageReceiver {
     let receivers: [FeatureMessageReceiver]