Add tests for RuntimeEnvironment. Respond to PR feedback.

Author: eerhardt

src/Cli/Microsoft.DotNet.Cli.Utils/RuntimeEnvironment.cs

@@ -18,15 +18,19 @@ internal enum Platform
 
     internal static class RuntimeEnvironment
     {
-        private static readonly string OverrideEnvironmentVariableName = "DOTNET_RUNTIME_ID";
-
         private static readonly Lazy<Platform> _platform = new Lazy<Platform>(DetermineOSPlatform);
         private static readonly Lazy<DistroInfo> _distroInfo = new Lazy<DistroInfo>(LoadDistroInfo);
 
         public static Platform OperatingSystemPlatform { get; } = GetOSPlatform();
         public static string OperatingSystemVersion { get; } = GetOSVersion();
         public static string OperatingSystem { get; } = GetOSName();
 
+        // toolset-tasks.csproj needs to build for full .NET Framework, and needs to get the current
+        // RuntimeIdentifier of the machine. Because of this, it needs to implement
+        // it's own GetRuntimeIdentifier(). All other places should use RuntimeInformation.RuntimeIdentifier.
+#if TOOLSET_TASKS
+        private static readonly string OverrideEnvironmentVariableName = "DOTNET_RUNTIME_ID";
+
         public static string GetRuntimeIdentifier()
         {
             return
@@ -105,6 +109,7 @@ private static string GetRIDOS()
                     return "unknown";
             }
         }
+#endif // TOOLSET_TASKS
 
         private class DistroInfo
         {

src/Layout/toolset-tasks/toolset-tasks.csproj

@@ -3,6 +3,7 @@
     <TargetFrameworks>$(SdkTargetFramework);net472</TargetFrameworks>
     <TargetFrameworks Condition="'$(OS)' != 'Windows_NT'">$(SdkTargetFramework)</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <DefineConstants>$(DefineConstants);TOOLSET_TASKS</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>

src/Tests/Microsoft.DotNet.Cli.Utils.Tests/RuntimeEnvironmentTests.cs

@@ -0,0 +1,57 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.InteropServices;
+using Microsoft.NET.TestFramework;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.DotNet.Cli.Utils.Tests
+{
+    public class RuntimeEnvironmentTests : SdkTest
+    {
+        public RuntimeEnvironmentTests(ITestOutputHelper log) : base(log)
+        {
+        }
+
+        [WindowsOnlyFact]
+        public void VerifyWindows()
+        {
+            Assert.Equal(Platform.Windows, RuntimeEnvironment.OperatingSystemPlatform);
+            Assert.Equal("Windows", RuntimeEnvironment.OperatingSystem);
+
+            VerifyOperatingSystemVersionEqualsEnvironmentOSVersion();
+        }
+
+        [MacOsOnlyFact]
+        public void VerifyMacOs()
+        {
+            Assert.Equal(Platform.Darwin, RuntimeEnvironment.OperatingSystemPlatform);
+            Assert.Equal("Mac OS X", RuntimeEnvironment.OperatingSystem);
+
+            VerifyOperatingSystemVersionEqualsEnvironmentOSVersion();
+        }
+
+        private void VerifyOperatingSystemVersionEqualsEnvironmentOSVersion()
+        {
+            Version osVersion = Version.Parse(RuntimeEnvironment.OperatingSystemVersion);
+            Version expectedOSVersion = Environment.OSVersion.Version;
+
+            Assert.Equal(expectedOSVersion.Major, osVersion.Major);
+            Assert.Equal(expectedOSVersion.Minor, osVersion.Minor);
+            Assert.Equal(expectedOSVersion.Build, osVersion.Build);
+        }
+
+        [LinuxOnlyFact]
+        public void VerifyLinux()
+        {
+            Assert.Equal(Platform.Linux, RuntimeEnvironment.OperatingSystemPlatform);
+
+            // ensure OperatingSystem and OperatingSystemVersion are aligned with the current RID
+            Assert.StartsWith(
+                $"{RuntimeEnvironment.OperatingSystem.ToLowerInvariant()}.{RuntimeEnvironment.OperatingSystemVersion}",
+                RuntimeInformation.RuntimeIdentifier);
+        }
+    }
+}