#5962 Change to early return of OS instead of throwing (#5963)

Author: juliankock

src/Libraries/Microsoft.Extensions.Diagnostics.ResourceMonitoring/README.md

@@ -1,6 +1,10 @@
 # Microsoft.Extensions.Diagnostics.ResourceMonitoring
 
-Measures and reports processor and memory usage. This library utilizes control groups (cgroups) in Linux to monitor system resources. Both cgroups v1 and v2 are supported.
+Measures and reports processor and memory usage. To monitor system resources, this library:
+
+- Utilizes control groups (cgroups) in Linux. Both cgroups v1 and v2 are supported.
+- Utilized Job Objects in Windows.
+- Mac OS is not supported.
 
 ## Install the package
 

src/Libraries/Microsoft.Extensions.Diagnostics.ResourceMonitoring/ResourceMonitoringServiceCollectionExtensions.cs

@@ -60,19 +60,21 @@ public static IServiceCollection AddResourceMonitoring(
         return services.AddResourceMonitoringInternal(configure);
     }
 
-    // can't easily test the exception throwing case
-    [ExcludeFromCodeCoverage]
     private static IServiceCollection AddResourceMonitoringInternal(
         this IServiceCollection services,
         Action<IResourceMonitorBuilder> configure)
     {
-        var builder = new ResourceMonitorBuilder(services);
-
         _ = services.AddMetrics();
-
+        var builder = new ResourceMonitorBuilder(services);
 #if NETFRAMEWORK
         _ = builder.AddWindowsProvider();
 #else
+        bool isSupportedOs = OperatingSystem.IsWindows() || OperatingSystem.IsLinux();
+        if (!isSupportedOs)
+        {
+            return services;
+        }
+
         if (OperatingSystem.IsWindows())
         {
             _ = builder.AddWindowsProvider();
@@ -81,10 +83,6 @@ private static IServiceCollection AddResourceMonitoringInternal(
         {
             _ = builder.AddLinuxProvider();
         }
-        else
-        {
-            throw new PlatformNotSupportedException();
-        }
 #endif
 
         configure.Invoke(builder);

test/Libraries/Microsoft.Extensions.Diagnostics.ResourceMonitoring.Tests/ResourceMonitoringExtensionsTests.cs

@@ -16,9 +16,9 @@
 
 namespace Microsoft.Extensions.Diagnostics.ResourceMonitoring.Test;
 
-[OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
 public sealed class ResourceMonitoringExtensionsTests
 {
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void Throw_Null_When_Registration_Ingredients_Null()
     {
@@ -30,6 +30,7 @@ public void Throw_Null_When_Registration_Ingredients_Null()
         Assert.Throws<ArgumentNullException>(() => services.AddResourceMonitoring((b) => b.ConfigureMonitor((Action<ResourceMonitoringOptions>)null!)));
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void AddsResourceMonitoringService_ToServicesCollection()
     {
@@ -50,6 +51,7 @@ public void AddsResourceMonitoringService_ToServicesCollection()
         Assert.IsAssignableFrom<IResourceMonitor>(trackerService);
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void AddsResourceMonitoringService_ToServicesCollection_NoArgs()
     {
@@ -66,6 +68,7 @@ public void AddsResourceMonitoringService_ToServicesCollection_NoArgs()
         Assert.IsAssignableFrom<IResourceMonitor>(trackerService);
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void AddsResourceMonitoringService_AsHostedService()
     {
@@ -87,6 +90,7 @@ public void AddsResourceMonitoringService_AsHostedService()
         Assert.IsAssignableFrom<IResourceMonitor>(trackerService);
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void ConfigureResourceUtilization_InitializeTrackerProperly()
     {
@@ -113,6 +117,7 @@ public void ConfigureResourceUtilization_InitializeTrackerProperly()
         Assert.NotNull(publisher);
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void ConfigureMonitor_GivenOptionsDelegate_InitializeTrackerWithOptionsProperly()
     {
@@ -141,6 +146,7 @@ public void ConfigureMonitor_GivenOptionsDelegate_InitializeTrackerWithOptionsPr
         Assert.Equal(TimeSpan.FromSeconds(CalculationPeriodValue), options!.Value.PublishingWindow);
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void ConfigureMonitor_GivenIConfigurationSection_InitializeTrackerWithOptionsProperly()
     {
@@ -182,6 +188,7 @@ public void ConfigureMonitor_GivenIConfigurationSection_InitializeTrackerWithOpt
         Assert.Equal(TimeSpan.FromSeconds(CalculationPeriod), options!.Value.PublishingWindow);
     }
 
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
     [ConditionalFact]
     public void Registering_Resource_Utilization_Adds_Only_One_Object_Of_Type_ResourceUtilizationService_To_DI_Container()
     {
@@ -204,4 +211,46 @@ public void Registering_Resource_Utilization_Adds_Only_One_Object_Of_Type_Resour
         Assert.IsAssignableFrom<ResourceMonitorService>(background);
         Assert.Same(tracker as ResourceMonitorService, background as ResourceMonitorService);
     }
+
+    [OSSkipCondition(OperatingSystems.Linux | OperatingSystems.Windows, SkipReason = "For MacOs only.")]
+    [ConditionalFact]
+    public void AddResourceMonitoringInternal_WhenMacOs_ReturnsSameServiceCollection()
+    {
+        var services = new ServiceCollection();
+
+        // Act
+        IServiceCollection result = services.AddResourceMonitoring();
+
+        // Assert
+        Assert.Same(services, result);
+        Assert.DoesNotContain(services, s => s.ServiceType == typeof(ISnapshotProvider));
+    }
+
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
+    [ConditionalFact]
+    public void AddResourceMonitoring_AddsISnapshotProvider()
+    {
+        var services = new ServiceCollection();
+
+        // Act
+        IServiceCollection result = services.AddResourceMonitoring();
+
+        // Assert
+        Assert.Same(services, result);
+        Assert.Contains(services, s => s.ServiceType == typeof(ISnapshotProvider));
+    }
+
+    [OSSkipCondition(OperatingSystems.MacOSX, SkipReason = "Not supported on MacOs.")]
+    [ConditionalFact]
+    public void AddResourceMonitoringInternal_CallsConfigureDelegate()
+    {
+        var services = new ServiceCollection();
+        bool delegateCalled = false;
+
+        // Act
+        services.AddResourceMonitoring(_ => delegateCalled = true);
+
+        // Assert
+        Assert.True(delegateCalled);
+    }
 }

test/TestUtilities/XUnit/OSSkipConditionAttribute.cs

@@ -60,7 +60,7 @@ private static OperatingSystems GetCurrentOS()
 
         throw new PlatformNotSupportedException();
 #else
-        // RuntimeInformation API is only avaialble in .NET Framework 4.7.1+
+        // RuntimeInformation API is only available in .NET Framework 4.7.1+
         // .NET Framework 4.7 and below can only run on Windows.
         return OperatingSystems.Windows;
 #endif