improve and clean up test codes

Author: smdn

tests/Smdn.Net.SmartMeter/Smdn.Net.SmartMeter/SmartMeterDataAggregatorServiceCollectionExtensions.cs

@@ -21,13 +21,15 @@ private static void ConfigureNothing(
     AddResiliencePipelineContext<string> context
   )
   {
+    // do nothing
   }
 
   private static void ConfigureNothing(
     ResiliencePipelineBuilder builder,
     AddResiliencePipelineContext<SmartMeterDataAggregator.ResiliencePipelineKeyPair<string>> context
   )
   {
+    // do nothing
   }
 
   private static void AssertResiliencePipelineRegistered(
@@ -42,6 +44,12 @@ string pipelineKey
       () => pipelineProvider.GetPipeline(pipelineKey),
       Throws.Nothing
     );
+    Assert.That(
+      pipelineProvider.GetPipeline(pipelineKey),
+      Is.SameAs(
+        pipelineProvider.GetPipeline(pipelineKey)
+      )
+    );
   }
 
   private static void AssertResiliencePipelineRegistered<TServiceKey>(
@@ -50,17 +58,24 @@ private static void AssertResiliencePipelineRegistered<TServiceKey>(
     string pipelineKey
   )
   {
-    foreach (var desc in services) {
-      Console.WriteLine(desc);
-    }
-
     var serviceProvider = services.BuildServiceProvider();
     var pipelineProvider = serviceProvider.GetRequiredKeyedService<ResiliencePipelineProvider<string>>(serviceKey: serviceKey);
 
+    Assert.That(
+      serviceProvider.GetRequiredKeyedService<ResiliencePipelineProvider<string>>(serviceKey: serviceKey),
+      Is.SameAs(pipelineProvider)
+    );
+
     Assert.That(
       () => pipelineProvider.GetPipeline(pipelineKey),
       Throws.Nothing
     );
+    Assert.That(
+      pipelineProvider.GetPipeline(pipelineKey),
+      Is.SameAs(
+        pipelineProvider.GetPipeline(pipelineKey)
+      )
+    );
   }
 
   [Test]