Make sure debounced values are delivered on specified scheduler. (#714)

* Make sure debounced values are delivered on specified scheduler.

* fix deferring too

* wip

Author: mbrandonw

Examples/Search/Search/SearchView.swift

@@ -68,7 +68,6 @@ let searchReducer = Reducer<SearchState, SearchAction, SearchEnvironment> {
 
     return environment.weatherClient
       .searchLocation(query)
-      .receive(on: environment.mainQueue)
       .catchToEffect()
       .debounce(id: SearchLocationId(), for: 0.3, scheduler: environment.mainQueue)
       .map(SearchAction.locationsResponse)

Sources/ComposableArchitecture/Effects/Debouncing.swift

@@ -14,8 +14,8 @@ extension Effect {
   ///   struct SearchId: Hashable {}
   ///
   ///   return environment.search(text)
-  ///     .map(Action.searchResponse)
   ///     .debounce(id: SearchId(), for: 0.5, scheduler: environment.mainQueue)
+  ///     .map(Action.searchResponse)
   /// ```
   ///
   /// - Parameters:
@@ -33,7 +33,7 @@ extension Effect {
     Just(())
       .setFailureType(to: Failure.self)
       .delay(for: dueTime, scheduler: scheduler, options: options)
-      .flatMap { self }
+      .flatMap { self.receive(on: scheduler) }
       .eraseToEffect()
       .cancellable(id: id, cancelInFlight: true)
   }

Sources/ComposableArchitecture/Effects/Deferring.swift

@@ -6,8 +6,8 @@ extension Effect {
   /// ```swift
   /// case let .textChanged(text):
   ///   return environment.search(text)
-  ///     .map(Action.searchResponse)
   ///     .deferred(for: 0.5, scheduler: environment.mainQueue)
+  ///     .map(Action.searchResponse)
   /// ```
   ///
   /// - Parameters:
@@ -24,7 +24,7 @@ extension Effect {
     Just(())
       .setFailureType(to: Failure.self)
       .delay(for: dueTime, scheduler: scheduler, options: options)
-      .flatMap { self }
+      .flatMap { self.receive(on: scheduler) }
       .eraseToEffect()
   }
 }