From 527b0e4c8d6f92be60d6da65da2d8151247633d2 Mon Sep 17 00:00:00 2001
From: alhardy <al_hardy@live.com.au>
Date: Mon, 12 Feb 2018 23:49:14 +1100
Subject: [PATCH] AppMetrics/MicrosoftExtensions#2 only register types deriving
 HealthCheck as health checks

---
 .../DefaultHealthCheckTypeProvider.cs         |  3 +-
 ...eCollectionHealthBuilderExtensionsTests.cs | 18 ++++++++++++
 .../TestHelpers/DontRegisterHealthCheck.cs    | 29 +++++++++++++++++++
 3 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 test/Health.Extensions.DependencyInjection.Facts/TestHelpers/DontRegisterHealthCheck.cs

diff --git a/src/App.Metrics.Health.Extensions.DependencyInjection/Internal/DefaultHealthCheckTypeProvider.cs b/src/App.Metrics.Health.Extensions.DependencyInjection/Internal/DefaultHealthCheckTypeProvider.cs
index eebc032..5012101 100644
--- a/src/App.Metrics.Health.Extensions.DependencyInjection/Internal/DefaultHealthCheckTypeProvider.cs
+++ b/src/App.Metrics.Health.Extensions.DependencyInjection/Internal/DefaultHealthCheckTypeProvider.cs
@@ -70,8 +70,7 @@ public IEnumerable<TypeInfo> HealthCheckTypes
                 return false;
             }
 
-            if (!typeInfo.Name.EndsWith(HealthCheckTypeName, StringComparison.OrdinalIgnoreCase) &&
-                !DerivesFromHealthCheck(typeInfo, candidateAssemblies))
+            if (!DerivesFromHealthCheck(typeInfo, candidateAssemblies))
             {
                 return false;
             }
diff --git a/test/Health.Extensions.DependencyInjection.Facts/ServiceCollectionHealthBuilderExtensionsTests.cs b/test/Health.Extensions.DependencyInjection.Facts/ServiceCollectionHealthBuilderExtensionsTests.cs
index 811f78a..22f4951 100644
--- a/test/Health.Extensions.DependencyInjection.Facts/ServiceCollectionHealthBuilderExtensionsTests.cs
+++ b/test/Health.Extensions.DependencyInjection.Facts/ServiceCollectionHealthBuilderExtensionsTests.cs
@@ -80,6 +80,24 @@ public void Should_scan_assembly_and_add_health_checks_and_ignore_obsolete_check
             health.Checks.Skip(1).First().Name.Should().Be("Referenced Health Check");
         }
 
+        [Fact]
+        public void Should_only_register_class_deriving_health_check()
+        {
+            // Arrange
+            var services = new ServiceCollection();
+            services.AddSingleton<IDatabase, Database>();
+
+            // Act
+            var unused = new HealthBuilder()
+                         .HealthChecks.RegisterFromAssembly(services, _fixture.DependencyContext)
+                         .BuildAndAddTo(services);
+            var provider = services.BuildServiceProvider();
+            var health = provider.GetRequiredService<IHealth>();
+
+            // Assert
+            health.Checks.FirstOrDefault(h => h.Name == nameof(DontRegisterHealthCheck)).Should().BeNull();
+        }
+
         [Fact]
         public void Should_append_resolved_health_checks_to_those_explicitly_registered()
         {
diff --git a/test/Health.Extensions.DependencyInjection.Facts/TestHelpers/DontRegisterHealthCheck.cs b/test/Health.Extensions.DependencyInjection.Facts/TestHelpers/DontRegisterHealthCheck.cs
new file mode 100644
index 0000000..d8f1447
--- /dev/null
+++ b/test/Health.Extensions.DependencyInjection.Facts/TestHelpers/DontRegisterHealthCheck.cs
@@ -0,0 +1,29 @@
+// <copyright file="DontRegisterHealthCheck.cs" company="Allan Hardy">
+// Copyright (c) Allan Hardy. All rights reserved.
+// </copyright>
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using App.Metrics.Health;
+
+namespace Health.Extensions.DependencyInjection.Facts.TestHelpers
+{
+    public class DontRegisterHealthCheck
+    {
+        public ValueTask<HealthCheckResult> CheckAsync(CancellationToken cancellationToken = default)
+        {
+            if (DateTime.UtcNow.Second <= 20)
+            {
+                return new ValueTask<HealthCheckResult>(HealthCheckResult.Degraded());
+            }
+
+            if (DateTime.UtcNow.Second >= 40)
+            {
+                return new ValueTask<HealthCheckResult>(HealthCheckResult.Unhealthy());
+            }
+
+            return new ValueTask<HealthCheckResult>(HealthCheckResult.Healthy());
+        }
+    }
+}