Add EmptyDisposable

Author: mjburghard

MobiusCore/Source/Disposables/EmptyDisposable.swift

@@ -0,0 +1,26 @@
+// Copyright 2019-2024 Spotify AB.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import Foundation
+
+/// The `EmptyDisposable` class implements a `Disposable` type for when you don't have anything to dispose of.
+public final class EmptyDisposable: MobiusCore.Disposable {
+
+    /// Create an `EmptyDisposable`
+    public init() {}
+
+    public func dispose() {
+        // No-op
+    }
+}

MobiusCore/Source/EffectHandlers/EffectRouterDSL.swift

@@ -42,7 +42,7 @@ public extension _PartialEffectRouter {
         return to { parameters, callback in
             fireAndForget(parameters)
             callback.end()
-            return AnonymousDisposable {}
+            return EmptyDisposable()
         }
     }
 
@@ -58,7 +58,7 @@ public extension _PartialEffectRouter {
                 callback.send(event)
             }
             callback.end()
-            return AnonymousDisposable {}
+            return EmptyDisposable()
         }
     }
 }

MobiusCore/Source/EventSources/CompositeEventSourceBuilder.swift

@@ -40,7 +40,7 @@ public struct CompositeEventSourceBuilder<Event> {
     public func build() -> AnyEventSource<Event> {
         switch eventSources.count {
         case 0:
-            return AnyEventSource { _ in AnonymousDisposable {} }
+            return AnyEventSource { _ in EmptyDisposable() }
         case 1:
             return eventSources[0]
         default:

MobiusCore/Source/Mobius.swift

@@ -74,7 +74,7 @@ public enum Mobius {
         return Builder(
             update: update,
             effectHandler: effectHandler,
-            eventSource: AnyEventSource({ _ in AnonymousDisposable(disposer: {}) }),
+            eventSource: AnyEventSource({ _ in EmptyDisposable() }),
             eventConsumerTransformer: { $0 },
             logger: AnyMobiusLogger(NoopLogger())
         )

MobiusCore/Test/EffectHandlers/EffectHandlerTests.swift

@@ -83,5 +83,5 @@ private func handleEffect(effect: Effect, callback: EffectCallback<Event>) -> Di
         callback.send(.eventForEffect1)
     }
     callback.end()
-    return AnonymousDisposable {}
+    return EmptyDisposable()
 }

MobiusCore/Test/EffectHandlers/EffectRouterDSLTests.swift

@@ -167,7 +167,7 @@ class EffectRouterDSLTests: QuickSpec {
                         expect(effect).to(equal(.effect1))
                         callback.send(.eventForEffect1)
                         callback.end()
-                        return AnonymousDisposable {}
+                        return EmptyDisposable()
                     }
                     .asConnectable
                     .connect { events.append($0) }

MobiusCore/Test/EffectHandlers/EffectRouterTests.swift

@@ -98,7 +98,7 @@ class EffectRouterTests: QuickSpec {
                         .to { _, callback in
                             callback.send(.eventForEffect2)
                             callback.end()
-                            return AnonymousDisposable {}
+                            return EmptyDisposable()
                         }
                     .asConnectable
 
@@ -119,7 +119,7 @@ class EffectRouterTests: QuickSpec {
 
             beforeEach {
                 let handler = AnyEffectHandler<Effect, Event> { _, _ in
-                    AnonymousDisposable {}
+                    EmptyDisposable()
                 }
                 let invalidRouter = EffectRouter<Effect, Event>()
                     .routeEffects(equalTo: .multipleHandlersForThisEffect).to(handler)
@@ -163,7 +163,7 @@ class EffectRouterTests: QuickSpec {
                     .routeEffects(equalTo: .effect2)
                         .to { _, callback in
                             callback.end()
-                            return AnonymousDisposable {}
+                            return EmptyDisposable()
                         }
                     .asConnectable
 

MobiusCore/Test/NonReentrancyTests.swift

@@ -67,7 +67,7 @@ class NonReentrancyTests: QuickSpec {
 
                 let testEffectHandler = AnyEffectHandler<Effect, Event> {
                     handleEffect($0, $1)
-                    return AnonymousDisposable {}
+                    return EmptyDisposable()
                 }
 
                 let effectConnectable = EffectRouter<Effect, Event>()

MobiusExtras/Test/EventSource+ExtensionsTests.swift

@@ -27,7 +27,7 @@ class EventSourceExtensionsTests: QuickSpec {
             beforeEach {
                 intEventSource = AnyEventSource { (consumer: @escaping (Int) -> Void) in
                     subscribedIntConsumer = consumer
-                    return AnonymousDisposable {}
+                    return EmptyDisposable()
                 }
             }