[30-74] FlowSlidingSpec (#6577)

* [30-74] `FlowSlidingSpec`

* Change to `async` TestKit

Author: eaba

src/core/Akka.Streams.Tests/Dsl/FlowSlidingSpec.cs

@@ -8,6 +8,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 using Akka.Actor;
 using Akka.Streams.Dsl;
 using Akka.Streams.TestKit;
@@ -84,10 +85,9 @@ private static List<List<int>> Sliding(List<int> source, int win, int step)
         }
 
         [Fact]
-        public void Sliding_must_behave_just_like_collections_sliding_with_step_lower_than_window()
+        public async Task Sliding_must_behave_just_like_collections_sliding_with_step_lower_than_window()
         {
-            this.AssertAllStagesStopped(() =>
-            {
+            await this.AssertAllStagesStoppedAsync(() => {
                 var random = new Random();
                 var gen = Enumerable.Range(1, 1000)
                     .Select(_ =>
@@ -97,14 +97,14 @@ public void Sliding_must_behave_just_like_collections_sliding_with_step_lower_th
                     });
 
                 Check(gen);
+                return Task.CompletedTask;
             }, Materializer);
         }
 
         [Fact]
-        public void Sliding_must_behave_just_like_collections_sliding_with_step_equals_window()
+        public async Task Sliding_must_behave_just_like_collections_sliding_with_step_equals_window()
         {
-            this.AssertAllStagesStopped(() =>
-            {
+            await this.AssertAllStagesStoppedAsync(() => {
                 var random = new Random();
                 var gen = Enumerable.Range(1, 1000)
                     .Select(_ =>
@@ -114,14 +114,14 @@ public void Sliding_must_behave_just_like_collections_sliding_with_step_equals_w
                     });
 
                 Check(gen);
+                return Task.CompletedTask;
             }, Materializer);
         }
 
         [Fact]
-        public void Sliding_must_behave_just_like_collections_sliding_with_step_greater_than_window()
+        public async Task Sliding_must_behave_just_like_collections_sliding_with_step_greater_than_window()
         {
-            this.AssertAllStagesStopped(() =>
-            {
+            await this.AssertAllStagesStoppedAsync(() => {
                 var random = new Random();
                 var gen = Enumerable.Range(1, 1000)
                     .Select(_ =>
@@ -131,23 +131,23 @@ public void Sliding_must_behave_just_like_collections_sliding_with_step_greater_
                     });
 
                 Check(gen);
+                return Task.CompletedTask;
             }, Materializer);
         }
 
         [Fact]
-        public void Sliding_must_work_with_empty_sources()
+        public async Task Sliding_must_work_with_empty_sources()
         {
-            this.AssertAllStagesStopped(() =>
-            {
-                Source.Empty<int>().Sliding(1).RunForeach(ints => TestActor.Tell(ints), Materializer)
-                    .ContinueWith(t =>
-                    {
-                        if (t.IsCompleted && t.Exception == null)
-                            TestActor.Tell("done");
-                    });
-                    
-
-                ExpectMsg("done");
+            await this.AssertAllStagesStoppedAsync(async() => {
+                await Source.Empty<int>().Sliding(1)
+                .RunForeach(ints => TestActor.Tell(ints), Materializer)                                                                             
+                .ContinueWith(t =>                                                                             
+                {                                                                                 
+                    if (t.IsCompleted && t.Exception == null)                                                                                     
+                        TestActor.Tell("done");                                                                             
+                });
+                await ExpectMsgAsync("done");
+                return Task.CompletedTask;
             }, Materializer);
         }
     }