Convert all unit test to proper async

src/Akka.sln

@@ -277,6 +277,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Akka.Persistence.Query.InMe
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Akka.Persistence.Query.InMemory.Tests", "contrib\persistence\Akka.Persistence.Query.InMemory.Tests\Akka.Persistence.Query.InMemory.Tests.csproj", "{407DD6E2-F274-4773-BA5E-43541D5C8D0F}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Junk", "Junk", "{CB7C415C-FD58-4527-AB88-FD084445A6A3}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -1418,6 +1420,7 @@ Global
 		{4022147A-4F95-4A04-BE09-01B7952BBDD9} = {A640E39E-F45C-4AE9-AABF-7F1432D357DA}
 		{A310BC3F-065A-4D0D-BC6A-9E444E96F10F} = {264C22A4-CAFC-41F6-B82C-4DDC5C196767}
 		{407DD6E2-F274-4773-BA5E-43541D5C8D0F} = {264C22A4-CAFC-41F6-B82C-4DDC5C196767}
+		{CB7C415C-FD58-4527-AB88-FD084445A6A3} = {D3AF8295-AEB5-4324-AA82-FCC0014AC310}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {03AD8E21-7507-4E68-A4E9-F4A7E7273164}

src/Directory.Build.props

@@ -6,11 +6,7 @@
     <PackageIcon>akkalogo.png</PackageIcon>
     <PackageProjectUrl>https://github.com/akkadotnet/akka.net</PackageProjectUrl>
     <PackageLicenseUrl>https://github.com/akkadotnet/akka.net/blob/master/LICENSE</PackageLicenseUrl>
-    <!-- 
-      xUnit1031 is a temporary fix, we will need to pay this technical debt 
-      and make everything fully async in the future 
-    -->
-    <NoWarn>$(NoWarn);CS1591;xUnit1013;xUnit1031</NoWarn>
+    <NoWarn>$(NoWarn);CS1591;xUnit1013</NoWarn>
     <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
   <!-- Set the language version for C# if we're not inside an F# project -->

src/contrib/cluster/Akka.Cluster.Metrics.Tests.MultiNode/ClustetMetricsRoutingSpec.cs

@@ -245,11 +245,10 @@ private async Task Should_prefer_node_with_more_free_memory_capacity()
 
             await RunOnAsync(async () =>
             {
-                await WithinAsync(20.Seconds(), () => {
+                await WithinAsync(20.Seconds(), async () => {
                     Sys.ActorOf(Props.Create<AdaptiveLoadBalancingRouterConfig.MemoryAllocator>(), "memory-allocator")
                                                                              .Tell(AdaptiveLoadBalancingRouterConfig.AllocateMemory.Instance);
-                    ExpectMsg("done");
-                    return Task.CompletedTask;
+                    await ExpectMsgAsync("done");
                 });
             }, _config.Node2);
 

src/contrib/cluster/Akka.Cluster.Metrics.Tests.MultiNode/Sample/StatsSampleSpec.cs

@@ -87,10 +87,10 @@ public async Task Stats_sample_should_illustrate_how_to_startup_cluster()
 
         private async Task Should_startup_cluster()
         {
-            await WithinAsync(15.Seconds(), () => {
+            await WithinAsync(15.Seconds(), async () => {
                 var cluster = Cluster.Get(Sys);
                 cluster.Subscribe(TestActor, typeof(ClusterEvent.MemberUp));
-                ExpectMsg<ClusterEvent.CurrentClusterState>();
+                await ExpectMsgAsync<ClusterEvent.CurrentClusterState>();
 
                 var firstAddress = Node(_config.First).Address;
                 var secondAddress = Node(_config.Second).Address;
@@ -101,13 +101,12 @@ private async Task Should_startup_cluster()
                 Sys.ActorOf(Props.Create<StatsWorker>(), "statsWorker");
                 Sys.ActorOf(Props.Create<StatsService>(), "statsService");
 
-                ReceiveN(3).Select(m => (m as ClusterEvent.MemberUp).Member.Address).Distinct()
+                (await ReceiveNAsync(3).Select(m => (m as ClusterEvent.MemberUp).Member.Address).Distinct().ToListAsync())
                     .Should().BeEquivalentTo(firstAddress, secondAddress, thirdAddress);
 
                 cluster.Unsubscribe(TestActor);
 
                 EnterBarrier("all-up");
-                return Task.CompletedTask;
             });
         }
 
@@ -130,10 +129,10 @@ private async Task AssertServiceOk()
             var service = Sys.ActorSelection(Node(_config.Third) / "user" / "statsService");
             // eventually the service should be ok,
             // first attempts might fail because worker actors not started yet
-            await AwaitAssertAsync(() =>
+            await AwaitAssertAsync(async () =>
             {
                service.Tell(new StatsJob("this is the text that will be analyzed"));
-               ExpectMsg<StatsResult>(1.Seconds()).MeanWordLength.Should().BeApproximately(3.875, 0.001);
+               (await ExpectMsgAsync<StatsResult>(1.Seconds())).MeanWordLength.Should().BeApproximately(3.875, 0.001);
             });
         }
     }