https://github.com/apple/swift-distributed-actors/issues/463

Author: yim-lee

Tests/ActorSingletonPluginTests/ActorSingletonPluginClusteredTests.swift

@@ -45,22 +45,24 @@ final class ActorSingletonPluginClusteredTests: ClusteredNodesTestBase {
                 settings.serialization.registerCodable(for: GreeterSingleton.Message.self, underId: 10001)
             }
 
+            // Bring up `ActorSingletonProxy` before setting up cluster (https://github.com/apple/swift-distributed-actors/issues/463)
+            let ref1 = try first.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-1")))
+            let ref2 = try second.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-2")))
+            let ref3 = try third.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-3")))
+
             first.cluster.join(node: second.cluster.node.node)
             third.cluster.join(node: second.cluster.node.node)
 
             // `first` will be the leader (lowest address) and runs the singleton
             try self.ensureNodes(.up, within: .seconds(10), nodes: first.cluster.node, second.cluster.node, third.cluster.node)
 
             let replyProbe1 = self.testKit(first).spawnTestProbe(expecting: String.self)
-            let ref1 = try first.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-1")))
             ref1.tell(.greet(name: "Charlie", _replyTo: replyProbe1.ref))
 
             let replyProbe2 = self.testKit(second).spawnTestProbe(expecting: String.self)
-            let ref2 = try second.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-2")))
             ref2.tell(.greet(name: "Charlie", _replyTo: replyProbe2.ref))
 
             let replyProbe3 = self.testKit(third).spawnTestProbe(expecting: String.self)
-            let ref3 = try third.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-3")))
             ref3.tell(.greet(name: "Charlie", _replyTo: replyProbe3.ref))
 
             try replyProbe1.expectMessage("Hello-1 Charlie!")
@@ -159,26 +161,26 @@ final class ActorSingletonPluginClusteredTests: ClusteredNodesTestBase {
                 settings.serialization.registerCodable(for: GreeterSingleton.Message.self, underId: 10001)
             }
 
+            // Bring up `ActorSingletonProxy` before setting up cluster (https://github.com/apple/swift-distributed-actors/issues/463)
+            let ref1 = try first.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-1")))
+            let ref2 = try second.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-2")))
+            let ref3 = try third.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-3")))
+            _ = try fourth.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-4")))
+
             first.cluster.join(node: second.cluster.node.node)
             third.cluster.join(node: second.cluster.node.node)
 
             try self.ensureNodes(.up, within: .seconds(10), nodes: first.cluster.node, second.cluster.node, third.cluster.node)
 
             let replyProbe1 = self.testKit(first).spawnTestProbe(expecting: String.self)
-            let ref1 = try first.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-1")))
             ref1.tell(.greet(name: "Charlie", _replyTo: replyProbe1.ref))
 
             let replyProbe2 = self.testKit(second).spawnTestProbe(expecting: String.self)
-            let ref2 = try second.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-2")))
             ref2.tell(.greet(name: "Charlie", _replyTo: replyProbe2.ref))
 
             let replyProbe3 = self.testKit(third).spawnTestProbe(expecting: String.self)
-            let ref3 = try third.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-3")))
             ref3.tell(.greet(name: "Charlie", _replyTo: replyProbe3.ref))
 
-            // Spawn the singleton on `fourth`
-            _ = try fourth.singleton.host(GreeterSingleton.Message.self, settings: singletonSettings, GreeterSingleton.makeBehavior(instance: GreeterSingleton("Hello-4")))
-
             // `first` has the lowest address so it should be the leader and singleton
             try replyProbe1.expectMessage("Hello-1 Charlie!")
             try replyProbe2.expectMessage("Hello-1 Charlie!")