Replaces references to Microsoft.Extensions.PlatformAbstractions with Microsoft.Extensions.PlatformAbstractions.Internal

Microsoft.DotNet.Cli.sln

@@ -109,6 +109,8 @@ Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "dotnet-run.Tests", "test\do
 EndProject
 Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "Performance", "test\Performance\Performance.xproj", "{6A3095FF-A7C5-4300-85A9-C025C384401D}"
 EndProject
+Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "binding-redirects.Tests", "test\binding-redirects.Tests\binding-redirects.Tests.xproj", "{27DBF851-F2E3-4FD5-BF4D-A73C81933283}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -777,6 +779,22 @@ Global
 		{6A3095FF-A7C5-4300-85A9-C025C384401D}.RelWithDebInfo|Any CPU.Build.0 = Release|Any CPU
 		{6A3095FF-A7C5-4300-85A9-C025C384401D}.RelWithDebInfo|x64.ActiveCfg = Release|Any CPU
 		{6A3095FF-A7C5-4300-85A9-C025C384401D}.RelWithDebInfo|x64.Build.0 = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Debug|x64.Build.0 = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.MinSizeRel|Any CPU.ActiveCfg = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.MinSizeRel|Any CPU.Build.0 = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.MinSizeRel|x64.ActiveCfg = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.MinSizeRel|x64.Build.0 = Debug|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Release|Any CPU.Build.0 = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Release|x64.ActiveCfg = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.Release|x64.Build.0 = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.RelWithDebInfo|Any CPU.ActiveCfg = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.RelWithDebInfo|Any CPU.Build.0 = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.RelWithDebInfo|x64.ActiveCfg = Release|Any CPU
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283}.RelWithDebInfo|x64.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -828,5 +846,6 @@ Global
 		{5FDA6D37-3A3E-4333-BA5C-F0B28BE316F4} = {17735A9D-BFD9-4585-A7CB-3208CA6EA8A7}
 		{35E3C2DC-9B38-4EC5-8DD7-C32458DC485F} = {17735A9D-BFD9-4585-A7CB-3208CA6EA8A7}
 		{6A3095FF-A7C5-4300-85A9-C025C384401D} = {17735A9D-BFD9-4585-A7CB-3208CA6EA8A7}
+		{27DBF851-F2E3-4FD5-BF4D-A73C81933283} = {17735A9D-BFD9-4585-A7CB-3208CA6EA8A7}
 	EndGlobalSection
 EndGlobal

TestAssets/DesktopTestProjects/DesktopKestrelSample/src/Startup.cs

@@ -12,7 +12,6 @@ using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Server.Kestrel;
 using Microsoft.AspNetCore.Server.Kestrel.Filter;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace SampleApp
 {
@@ -21,7 +20,7 @@ namespace SampleApp
         private static string Args { get; set; }
         private static CancellationTokenSource ServerCancellationTokenSource { get; set; }
 
-        public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory, IApplicationEnvironment env)
+        public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
         {
             var ksi = app.ServerFeatures.Get<IKestrelServerInformation>();
             ksi.NoDelay = true;

TestAssets/TestProjects/KestrelSample/src/Startup.cs

@@ -12,7 +12,6 @@ using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Server.Kestrel;
 using Microsoft.AspNetCore.Server.Kestrel.Filter;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace SampleApp
 {
@@ -21,7 +20,7 @@ namespace SampleApp
         private static string Args { get; set; }
         private static CancellationTokenSource ServerCancellationTokenSource { get; set; }
 
-        public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory, IApplicationEnvironment env)
+        public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
         {
             var ksi = app.ServerFeatures.Get<IKestrelServerInformation>();
             ksi.NoDelay = true;

scripts/Microsoft.DotNet.Cli.Build.Framework/CurrentArchitecture.cs

@@ -1,5 +1,5 @@
 using System;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Cli.Build.Framework
 {
@@ -17,7 +17,7 @@ namespace Microsoft.DotNet.Cli.Build.Framework
         {
             get
             {
-                var archName = PlatformServices.Default.Runtime.RuntimeArchitecture;
+                var archName = RuntimeEnvironment.RuntimeArchitecture;
                 return string.Equals(archName, "x86", StringComparison.OrdinalIgnoreCase);
             }
         }
@@ -26,7 +26,7 @@ namespace Microsoft.DotNet.Cli.Build.Framework
         {
             get
             {
-                var archName = PlatformServices.Default.Runtime.RuntimeArchitecture;
+                var archName = RuntimeEnvironment.RuntimeArchitecture;
                 return string.Equals(archName, "x64", StringComparison.OrdinalIgnoreCase);
             }
         }

scripts/Microsoft.DotNet.Cli.Build.Framework/CurrentPlatform.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Cli.Build.Framework
 {
@@ -34,7 +34,7 @@ namespace Microsoft.DotNet.Cli.Build.Framework
         {
             get
             {
-                var osname = PlatformServices.Default.Runtime.OperatingSystem;
+                var osname = RuntimeEnvironment.OperatingSystem;
                 return string.Equals(osname, "ubuntu", StringComparison.OrdinalIgnoreCase);
             }
         }
@@ -43,7 +43,7 @@ namespace Microsoft.DotNet.Cli.Build.Framework
         {
             get
             {
-                var osname = PlatformServices.Default.Runtime.OperatingSystem;
+                var osname = RuntimeEnvironment.OperatingSystem;
                 return string.Equals(osname, "centos", StringComparison.OrdinalIgnoreCase);
             }
         }
@@ -52,7 +52,7 @@ namespace Microsoft.DotNet.Cli.Build.Framework
         {
             get
             {
-                var osname = PlatformServices.Default.Runtime.OperatingSystem;
+                var osname = RuntimeEnvironment.OperatingSystem;
                 return string.Equals(osname, "rhel", StringComparison.OrdinalIgnoreCase);
             }
         }
@@ -69,7 +69,7 @@ namespace Microsoft.DotNet.Cli.Build.Framework
         {
             get
             {
-                var osname = PlatformServices.Default.Runtime.OperatingSystem;
+                var osname = RuntimeEnvironment.OperatingSystem;
                 return string.Equals(osname, "debian", StringComparison.OrdinalIgnoreCase);
             }
         }

scripts/Microsoft.DotNet.Cli.Build.Framework/project.json

@@ -1,10 +1,19 @@
 {
   "version": "1.0.0-*",
+  "compilationOptions": {
+    "warningsAsErrors": true,
+    "allowUnsafe": true
+  },
   "dependencies": {
     "NETStandard.Library": "1.5.0-rc2-24027",
     "System.Diagnostics.Process": "4.1.0-rc2-24027",
-    "Microsoft.Extensions.PlatformAbstractions": "1.0.0-rc2-20581"
+    "System.Reflection.TypeExtensions": "4.1.0-rc2-24027"
   },
+  "compile": [
+    "../../src/Microsoft.DotNet.InternalAbstractions/RuntimeEnvironment.cs",
+    "../../src/Microsoft.DotNet.InternalAbstractions/Platform.cs",
+    "../../src/Microsoft.DotNet.InternalAbstractions/Native/*.cs"
+  ],
   "frameworks": {
     "netstandard1.3": {
       "imports": "dnxcore50"

scripts/dotnet-cli-build/CompileTargets.cs

@@ -1,18 +1,15 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Text;
 using System.Linq;
 using System.Runtime.InteropServices;
+using System.Text;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
-
-using static Microsoft.DotNet.Cli.Build.FS;
-using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
-using System.Text.RegularExpressions;
-using System.Reflection.PortableExecutable;
-using Newtonsoft.Json.Linq;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
+using static Microsoft.DotNet.Cli.Build.FS;
 
 namespace Microsoft.DotNet.Cli.Build
 {
@@ -37,9 +34,9 @@ namespace Microsoft.DotNet.Cli.Build
         };
 
         public static string HostPackagePlatformRid => HostPackageSupportedRids[
-                             (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+                             (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
-                             ? $"win7-{PlatformServices.Default.Runtime.RuntimeArchitecture}"
+                             ? $"win7-{RuntimeEnvironment.RuntimeArchitecture}"
-                             : PlatformServices.Default.Runtime.GetRuntimeIdentifier()];
+                             : RuntimeEnvironment.GetRuntimeIdentifier()];
 
         public static readonly Dictionary<string, string> HostPackageSupportedRids = new Dictionary<string, string>()
         {
@@ -479,13 +476,13 @@ namespace Microsoft.DotNet.Cli.Build
             string SharedFrameworkNugetVersion = c.BuildContext.Get<string>("SharedFrameworkNugetVersion");
 
             string sharedFrameworkRid;
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
-                sharedFrameworkRid = $"win7-{PlatformServices.Default.Runtime.RuntimeArchitecture}";
+                sharedFrameworkRid = $"win7-{RuntimeEnvironment.RuntimeArchitecture}";
             }
             else
             {
-                sharedFrameworkRid = PlatformServices.Default.Runtime.GetRuntimeIdentifier();
+                sharedFrameworkRid = RuntimeEnvironment.GetRuntimeIdentifier();
             }
 
             string SharedFrameworkSourceRoot = GenerateSharedFrameworkProject(c, SharedFrameworkTemplateSourceRoot, sharedFrameworkRid);
@@ -524,7 +521,7 @@ namespace Microsoft.DotNet.Cli.Build
 
             // Generate RID fallback graph
             string runtimeGraphGeneratorRuntime = null;
-            switch (PlatformServices.Default.Runtime.OperatingSystemPlatform)
+            switch (RuntimeEnvironment.OperatingSystemPlatform)
             {
                 case Platform.Windows:
                     runtimeGraphGeneratorRuntime = "win";
@@ -553,7 +550,7 @@ namespace Microsoft.DotNet.Cli.Build
             }
             else
             {
-                c.Error($"Could not determine rid graph generation runtime for platform {PlatformServices.Default.Runtime.OperatingSystemPlatform}");
+                c.Error($"Could not determine rid graph generation runtime for platform {RuntimeEnvironment.OperatingSystemPlatform}");
             }
 
             File.Copy(

scripts/dotnet-cli-build/DebTargets.cs

@@ -4,7 +4,7 @@ using System.IO;
 using System.IO.Compression;
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 

scripts/dotnet-cli-build/InstallerTargets.cs

@@ -1,12 +1,4 @@
-using System;
+using Microsoft.DotNet.Cli.Build.Framework;
-using System.Collections.Generic;
-using System.IO;
-using System.IO.Compression;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
-
-using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 
 namespace Microsoft.DotNet.Cli.Build
 {

scripts/dotnet-cli-build/MsiTargets.cs

@@ -5,7 +5,7 @@ using System.IO.Compression;
 using System.Net.Http;
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 

scripts/dotnet-cli-build/PackageTargets.cs

@@ -4,8 +4,7 @@ using System.IO;
 using System.IO.Compression;
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
-
 using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 
 namespace Microsoft.DotNet.Cli.Build
@@ -261,11 +260,11 @@ namespace Microsoft.DotNet.Cli.Build
             // This is overkill, but I want to cover all the variables used in all OSes (including where some have the same names)
             var buildVersion = c.BuildContext.Get<BuildVersion>("BuildVersion");
             var configuration = c.BuildContext.Get<string>("Configuration");
-            var architecture = PlatformServices.Default.Runtime.RuntimeArchitecture;
+            var architecture = RuntimeEnvironment.RuntimeArchitecture;
             var env = new Dictionary<string, string>()
             {
-                { "RID", PlatformServices.Default.Runtime.GetRuntimeIdentifier() },
+                { "RID", RuntimeEnvironment.GetRuntimeIdentifier() },
-                { "OSNAME", PlatformServices.Default.Runtime.OperatingSystem },
+                { "OSNAME", RuntimeEnvironment.OperatingSystem },
                 { "TFM", "dnxcore50" },
                 { "REPOROOT", Dirs.RepoRoot },
                 { "OutputDir", Dirs.Output },

scripts/dotnet-cli-build/PkgTargets.cs

@@ -4,7 +4,7 @@ using System.IO;
 using System.IO.Compression;
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 

scripts/dotnet-cli-build/PrepareTargets.cs

@@ -7,8 +7,7 @@ using System.Runtime.InteropServices;
 using System.Text;
 using System.Text.RegularExpressions;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
-using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 using static Microsoft.DotNet.Cli.Build.FS;
@@ -37,8 +36,6 @@ namespace Microsoft.DotNet.Cli.Build
         [Target(nameof(GenerateVersions), nameof(UpdateTemplateVersions), nameof(CheckPrereqs), nameof(LocateStage0), nameof(ExpectedBuildArtifacts))]
         public static BuildTargetResult Init(BuildTargetContext c)
         {
-            var runtimeInfo = PlatformServices.Default.Runtime;
-
             var configEnv = Environment.GetEnvironmentVariable("CONFIGURATION");
 
             if (string.IsNullOrEmpty(configEnv))
@@ -51,8 +48,8 @@ namespace Microsoft.DotNet.Cli.Build
 
             c.Info($"Building {c.BuildContext["Configuration"]} to: {Dirs.Output}");
             c.Info("Build Environment:");
-            c.Info($" Operating System: {runtimeInfo.OperatingSystem} {runtimeInfo.OperatingSystemVersion}");
+            c.Info($" Operating System: {RuntimeEnvironment.OperatingSystem} {RuntimeEnvironment.OperatingSystemVersion}");
-            c.Info($" Platform: {runtimeInfo.OperatingSystemPlatform}");
+            c.Info($" Platform: {RuntimeEnvironment.OperatingSystemPlatform}");
 
             return c.Success();
         }

scripts/dotnet-cli-build/TestPackageProjects.cs

@@ -1,14 +1,5 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Build.Framework;
 
-using static Microsoft.DotNet.Cli.Build.FS;
-using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
-using static Microsoft.DotNet.Cli.Build.Utils;
-
 namespace Microsoft.DotNet.Cli.Build
 {
     public static class TestPackageProjects

scripts/dotnet-cli-build/Utils/Crossgen.cs

@@ -2,10 +2,8 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Build.Framework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
-
 using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
 
 namespace Microsoft.DotNet.Cli.Build
@@ -28,7 +26,7 @@ namespace Microsoft.DotNet.Cli.Build
 
         private string GetCrossgenPathForVersion()
         {
-            string arch = PlatformServices.Default.Runtime.RuntimeArchitecture;
+            string arch = RuntimeEnvironment.RuntimeArchitecture;
             string packageId;
             if (CurrentPlatform.IsWindows)
             {

scripts/dotnet-cli-build/Utils/Dirs.cs

@@ -1,7 +1,7 @@
-using Microsoft.Extensions.PlatformAbstractions;
+using System;
-using System;
 using System.IO;
 using System.Runtime.InteropServices;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Cli.Build
 {
@@ -11,7 +11,7 @@ namespace Microsoft.DotNet.Cli.Build
         public static readonly string Output = Path.Combine(
             RepoRoot,
             "artifacts",
-            PlatformServices.Default.Runtime.GetRuntimeIdentifier());
+            RuntimeEnvironment.GetRuntimeIdentifier());
 
         public static readonly string Intermediate = Path.Combine(Output, "intermediate");
         public static readonly string PackagesIntermediate = Path.Combine(Output, "packages/intermediate");

scripts/dotnet-cli-build/Utils/DotNetCli.cs

@@ -1,8 +1,8 @@
-using Microsoft.DotNet.Cli.Build.Framework;
+using System.IO;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
+using Microsoft.DotNet.Cli.Build.Framework;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Cli.Build
 {
@@ -43,12 +43,12 @@ namespace Microsoft.DotNet.Cli.Build
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
                 return Path.Combine(Directory.GetCurrentDirectory(), ".dotnet_stage0",
-                    PlatformServices.Default.Runtime.OperatingSystemPlatform.ToString(),
+                    RuntimeEnvironment.OperatingSystemPlatform.ToString(),
-                    PlatformServices.Default.Runtime.RuntimeArchitecture);
+                    RuntimeEnvironment.RuntimeArchitecture);
             }
             else
             {
-                return Path.Combine(Directory.GetCurrentDirectory(), ".dotnet_stage0", PlatformServices.Default.Runtime.OperatingSystemPlatform.ToString());
+                return Path.Combine(Directory.GetCurrentDirectory(), ".dotnet_stage0", RuntimeEnvironment.OperatingSystemPlatform.ToString());
             }
 
         }

src/Microsoft.DotNet.Cli.Utils/CommandResolution/AbstractPathBasedCommandResolver.cs

@@ -1,13 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 namespace Microsoft.DotNet.Cli.Utils
 {
     public abstract class AbstractPathBasedCommandResolver : ICommandResolver

src/Microsoft.DotNet.Cli.Utils/CommandResolution/AppBaseCommandResolver.cs

@@ -1,24 +1,16 @@
-using System;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Collections.Generic;
+
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 namespace Microsoft.DotNet.Cli.Utils
 {
     public class AppBaseCommandResolver : AbstractPathBasedCommandResolver
     {
-        public AppBaseCommandResolver(IEnvironmentProvider environment, 
+        public AppBaseCommandResolver(IEnvironmentProvider environment,
             IPlatformCommandSpecFactory commandSpecFactory) : base(environment, commandSpecFactory) { }
 
         internal override string ResolveCommandPath(CommandResolverArguments commandResolverArguments)
         {
             return _environment.GetCommandPathFromRootPath(
-                PlatformServices.Default.Application.ApplicationBasePath, 
+                ApplicationEnvironment.ApplicationBasePath,
                 commandResolverArguments.CommandName);
         }
 

src/Microsoft.DotNet.Cli.Utils/CommandResolution/AppBaseDllCommandResolver.cs

@@ -1,7 +1,7 @@
 using System.IO;
 using System.Linq;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -15,7 +15,7 @@ namespace Microsoft.DotNet.Cli.Utils
             }
             if (commandResolverArguments.CommandName.EndsWith(FileNameSuffixes.DotNet.DynamicLib))
             {
-                var localPath = Path.Combine(PlatformServices.Default.Application.ApplicationBasePath,
+                var localPath = Path.Combine(ApplicationEnvironment.ApplicationBasePath,
                     commandResolverArguments.CommandName);
                 if (File.Exists(localPath))
                 {

src/Microsoft.DotNet.Cli.Utils/CommandResolution/CompositeCommandResolver.cs

@@ -1,13 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -15,9 +6,9 @@ namespace Microsoft.DotNet.Cli.Utils
     {
         private IList<ICommandResolver> _orderedCommandResolvers;
 
-        public IEnumerable<ICommandResolver> OrderedCommandResolvers 
+        public IEnumerable<ICommandResolver> OrderedCommandResolvers
         {
-            get 
+            get
             {
                 return _orderedCommandResolvers;
             }
@@ -32,7 +23,7 @@ namespace Microsoft.DotNet.Cli.Utils
         {
             _orderedCommandResolvers.Add(commandResolver);
         }
-        
+
         public CommandSpec Resolve(CommandResolverArguments commandResolverArguments)
         {
             foreach (var commandResolver in _orderedCommandResolvers)

src/Microsoft.DotNet.Cli.Utils/CommandResolution/DefaultCommandResolverPolicy.cs

@@ -1,13 +1,4 @@
-using System;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -19,7 +10,7 @@ namespace Microsoft.DotNet.Cli.Utils
             var packagedCommandSpecFactory = new PackagedCommandSpecFactory();
 
             var platformCommandSpecFactory = default(IPlatformCommandSpecFactory);
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
                 platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
             }

src/Microsoft.DotNet.Cli.Utils/CommandResolution/DepsJsonCommandResolver.cs

@@ -2,26 +2,15 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.DotNet.ProjectModel.Compilation;
 using Microsoft.Extensions.DependencyModel;
-using Microsoft.Extensions.PlatformAbstractions;
-using Microsoft.DotNet.ProjectModel.Resolution;
-using NuGet.Frameworks;
-using NuGet.Packaging;
-using NuGet.ProjectModel;
-
-using LockFile = Microsoft.DotNet.ProjectModel.Graph.LockFile;
-using FileFormatException = Microsoft.DotNet.ProjectModel.FileFormatException;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
     public class DepsJsonCommandResolver : ICommandResolver
     {
-        private static readonly string[] s_extensionPreferenceOrder = new [] 
+        private static readonly string[] s_extensionPreferenceOrder = new[]
-        { 
+        {
             "",
             ".exe",
             ".dll"
@@ -30,7 +19,7 @@ namespace Microsoft.DotNet.Cli.Utils
         private string _nugetPackageRoot;
         private Muxer _muxer;
 
-        public DepsJsonCommandResolver(string nugetPackageRoot) 
+        public DepsJsonCommandResolver(string nugetPackageRoot)
             : this(new Muxer(), nugetPackageRoot) { }
 
         public DepsJsonCommandResolver(Muxer muxer, string nugetPackageRoot)
@@ -46,16 +35,16 @@ namespace Microsoft.DotNet.Cli.Utils
             {
                 return null;
             }
-            
+
             return ResolveFromDepsJsonFile(
-                commandResolverArguments.CommandName, 
+                commandResolverArguments.CommandName,
                 commandResolverArguments.CommandArguments.OrEmptyIfNull(),
                 commandResolverArguments.DepsJsonFile);
         }
 
         private CommandSpec ResolveFromDepsJsonFile(
-            string commandName, 
+            string commandName,
-            IEnumerable<string> commandArgs, 
+            IEnumerable<string> commandArgs,
             string depsJsonFile)
         {
             var dependencyContext = LoadDependencyContextFromFile(depsJsonFile);
@@ -67,8 +56,8 @@ namespace Microsoft.DotNet.Cli.Utils
             }
 
             return CreateCommandSpecUsingMuxerIfPortable(
-                commandPath, 
+                commandPath,
-                commandArgs, 
+                commandArgs,
                 depsJsonFile,
                 CommandResolutionStrategy.DepsFile,
                 _nugetPackageRoot,
@@ -93,11 +82,11 @@ namespace Microsoft.DotNet.Cli.Utils
             var commandCandidates = new List<CommandCandidate>();
 
             var assemblyCommandCandidates = GetCommandCandidates(
-                commandName, 
+                commandName,
-                dependencyContext, 
+                dependencyContext,
                 CommandCandidateType.RuntimeCommandCandidate);
             var nativeCommandCandidates = GetCommandCandidates(
-                commandName, 
+                commandName,
                 dependencyContext,
                 CommandCandidateType.NativeCommandCandidate);
 
@@ -110,7 +99,7 @@ namespace Microsoft.DotNet.Cli.Utils
         }
 
         private IEnumerable<CommandCandidate> GetCommandCandidates(
-            string commandName, 
+            string commandName,
             DependencyContext dependencyContext,
             CommandCandidateType commandCandidateType)
         {
@@ -133,7 +122,7 @@ namespace Microsoft.DotNet.Cli.Utils
                                     commandName,
                                     runtimeAssetGroups,
                                     runtimeLibrary.Name,
-                                    runtimeLibrary.Version));            
+                                    runtimeLibrary.Version));
             }
 
             return commandCandidates;
@@ -141,14 +130,14 @@ namespace Microsoft.DotNet.Cli.Utils
 
         private IEnumerable<CommandCandidate> GetCommandCandidatesFromRuntimeAssetGroups(
             string commandName,
-            IEnumerable<RuntimeAssetGroup> runtimeAssetGroups, 
+            IEnumerable<RuntimeAssetGroup> runtimeAssetGroups,
             string PackageName,
             string PackageVersion)
         {
             var candidateAssetGroups = runtimeAssetGroups
                 .Where(r => r.Runtime == string.Empty)
-                .Where(a => 
+                .Where(a =>
-                    a.AssetPaths.Any(p => 
+                    a.AssetPaths.Any(p =>
                         Path.GetFileNameWithoutExtension(p).Equals(commandName, StringComparison.OrdinalIgnoreCase)));
 
             var commandCandidates = new List<CommandCandidate>();
@@ -190,9 +179,9 @@ namespace Microsoft.DotNet.Cli.Utils
         }
 
         private CommandSpec CreateCommandSpecUsingMuxerIfPortable(
-            string commandPath, 
+            string commandPath,
-            IEnumerable<string> commandArgs, 
+            IEnumerable<string> commandArgs,
-            string depsJsonFile, 
+            string depsJsonFile,
             CommandResolutionStrategy commandResolutionStrategy,
             string nugetPackagesRoot,
             bool isPortable)
@@ -248,9 +237,9 @@ namespace Microsoft.DotNet.Cli.Utils
             public string GetAbsoluteCommandPath(string nugetPackageRoot)
             {
                 return Path.Combine(
-                    nugetPackageRoot.Replace('/', Path.DirectorySeparatorChar), 
+                    nugetPackageRoot.Replace('/', Path.DirectorySeparatorChar),
-                    PackageName.Replace('/', Path.DirectorySeparatorChar), 
+                    PackageName.Replace('/', Path.DirectorySeparatorChar),
-                    PackageVersion.Replace('/', Path.DirectorySeparatorChar), 
+                    PackageVersion.Replace('/', Path.DirectorySeparatorChar),
                     RelativeCommandPath.Replace('/', Path.DirectorySeparatorChar));
             }
         }

src/Microsoft.DotNet.Cli.Utils/CommandResolution/GenericPlatformCommandSpecFactory.cs

@@ -1,13 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {

src/Microsoft.DotNet.Cli.Utils/CommandResolution/IPlatformCommandSpecFactory.cs

@@ -1,13 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {

src/Microsoft.DotNet.Cli.Utils/CommandResolution/OutputPathCommandResolver.cs

@@ -1,13 +1,8 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Runtime.InteropServices;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -78,7 +73,7 @@ namespace Microsoft.DotNet.Cli.Utils
             var projectContext = ProjectContext.Create(
                 projectRootPath,
                 framework,
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers());
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers());
 
             if (projectContext.RuntimeIdentifier == null)
             {

src/Microsoft.DotNet.Cli.Utils/CommandResolution/PathCommandResolver.cs

@@ -1,19 +1,8 @@
-using System;
+namespace Microsoft.DotNet.Cli.Utils
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
-
-namespace Microsoft.DotNet.Cli.Utils
 {
     public class PathCommandResolver : AbstractPathBasedCommandResolver
     {
-        public PathCommandResolver(IEnvironmentProvider environment, 
+        public PathCommandResolver(IEnvironmentProvider environment,
             IPlatformCommandSpecFactory commandSpecFactory) : base(environment, commandSpecFactory) { }
 
         internal override string ResolveCommandPath(CommandResolverArguments commandResolverArguments)

src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectDependenciesCommandResolver.cs

@@ -2,9 +2,9 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.Cli.Utils
@@ -128,7 +128,7 @@ namespace Microsoft.DotNet.Cli.Utils
             return ProjectContext.Create(
                 projectRootPath,
                 framework,
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers());
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers());
 
         }
 

src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectPathCommandResolver.cs

@@ -1,19 +1,8 @@
-using System;
+namespace Microsoft.DotNet.Cli.Utils
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
-
-namespace Microsoft.DotNet.Cli.Utils
 {
     public class ProjectPathCommandResolver : AbstractPathBasedCommandResolver
     {
-        public ProjectPathCommandResolver(IEnvironmentProvider environment, 
+        public ProjectPathCommandResolver(IEnvironmentProvider environment,
             IPlatformCommandSpecFactory commandSpecFactory) : base(environment, commandSpecFactory) { }
 
         internal override string ResolveCommandPath(CommandResolverArguments commandResolverArguments)
@@ -24,7 +13,7 @@ namespace Microsoft.DotNet.Cli.Utils
             }
 
             return _environment.GetCommandPathFromRootPath(
-                commandResolverArguments.ProjectDirectory, 
+                commandResolverArguments.ProjectDirectory,
                 commandResolverArguments.CommandName,
                 commandResolverArguments.InferredExtensions.OrEmptyIfNull());
         }

src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectToolsCommandResolver.cs

@@ -2,29 +2,24 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.DotNet.ProjectModel.Compilation;
 using Microsoft.Extensions.DependencyModel;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
-using NuGet.Packaging;
-using NuGet.ProjectModel;
-
-using LockFile = Microsoft.DotNet.ProjectModel.Graph.LockFile;
 using FileFormatException = Microsoft.DotNet.ProjectModel.FileFormatException;
+using LockFile = Microsoft.DotNet.ProjectModel.Graph.LockFile;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
     public class ProjectToolsCommandResolver : ICommandResolver
     {
         private static readonly NuGetFramework s_toolPackageFramework = FrameworkConstants.CommonFrameworks.NetCoreApp10;
-        
+
-        private static readonly CommandResolutionStrategy s_commandResolutionStrategy = 
+        private static readonly CommandResolutionStrategy s_commandResolutionStrategy =
             CommandResolutionStrategy.ProjectToolsPackage;
 
-        private static readonly string s_currentRuntimeIdentifier = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+        private static readonly string s_currentRuntimeIdentifier = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
 
 
         private List<string> _allowedCommandExtensions;
@@ -34,7 +29,7 @@ namespace Microsoft.DotNet.Cli.Utils
         {
             _packagedCommandSpecFactory = packagedCommandSpecFactory;
 
-            _allowedCommandExtensions = new List<string>() 
+            _allowedCommandExtensions = new List<string>()
             {
                 FileNameSuffixes.DotNet.DynamicLib
             };
@@ -47,15 +42,15 @@ namespace Microsoft.DotNet.Cli.Utils
             {
                 return null;
             }
-            
+
             return ResolveFromProjectTools(
-                commandResolverArguments.CommandName, 
+                commandResolverArguments.CommandName,
                 commandResolverArguments.CommandArguments.OrEmptyIfNull(),
                 commandResolverArguments.ProjectDirectory);
         }
 
         private CommandSpec ResolveFromProjectTools(
-            string commandName, 
+            string commandName,
             IEnumerable<string> args,
             string projectDirectory)
         {
@@ -70,7 +65,7 @@ namespace Microsoft.DotNet.Cli.Utils
 
             return ResolveCommandSpecFromAllToolLibraries(
                 toolsLibraries,
-                commandName, 
+                commandName,
                 args,
                 projectContext);
         }
@@ -101,7 +96,7 @@ namespace Microsoft.DotNet.Cli.Utils
             ProjectContext projectContext)
         {
             var nugetPackagesRoot = projectContext.PackagesDirectory;
-            
+
             var lockFile = GetToolLockFile(toolLibraryRange, nugetPackagesRoot);
 
             var toolLibrary = lockFile.Targets
@@ -112,10 +107,10 @@ namespace Microsoft.DotNet.Cli.Utils
             {
                 return null;
             }
-            
+
             var depsFileRoot = Path.GetDirectoryName(lockFile.LockFilePath);
             var depsFilePath = GetToolDepsFilePath(toolLibraryRange, lockFile, depsFileRoot);
-            
+
             return _packagedCommandSpecFactory.CreateCommandSpecFromLibrary(
                     toolLibrary,
                     commandName,
@@ -159,8 +154,8 @@ namespace Microsoft.DotNet.Cli.Utils
             var toolPathCalculator = new ToolPathCalculator(nugetPackagesRoot);
 
             return toolPathCalculator.GetBestLockFilePath(
-                toolLibrary.Name, 
+                toolLibrary.Name,
-                toolLibrary.VersionRange, 
+                toolLibrary.VersionRange,
                 s_toolPackageFramework);
         }
 
@@ -182,8 +177,8 @@ namespace Microsoft.DotNet.Cli.Utils
         }
 
         private string GetToolDepsFilePath(
-            LibraryRange toolLibrary, 
+            LibraryRange toolLibrary,
-            LockFile toolLockFile, 
+            LockFile toolLockFile,
             string depsPathRoot)
         {
             var depsJsonPath = Path.Combine(
@@ -196,7 +191,7 @@ namespace Microsoft.DotNet.Cli.Utils
         }
 
         private void EnsureToolJsonDepsFileExists(
-            LockFile toolLockFile, 
+            LockFile toolLockFile,
             string depsPath)
         {
             if (!File.Exists(depsPath))
@@ -207,7 +202,7 @@ namespace Microsoft.DotNet.Cli.Utils
 
         // Need to unit test this, so public
         public void GenerateDepsJsonFile(
-            LockFile toolLockFile, 
+            LockFile toolLockFile,
             string depsPath)
         {
             Reporter.Verbose.WriteLine($"Generating deps.json at: {depsPath}");
@@ -220,11 +215,11 @@ namespace Microsoft.DotNet.Cli.Utils
             var exporter = projectContext.CreateExporter(Constants.DefaultConfiguration);
 
             var dependencyContext = new DependencyContextBuilder()
-                .Build(null, 
+                .Build(null,
-                    null, 
+                    null,
                     exporter.GetAllExports(),
-                    true, 
+                    true,
-                    s_toolPackageFramework, 
+                    s_toolPackageFramework,
                     string.Empty);
 
             var tempDepsFile = Path.GetTempFileName();
@@ -250,7 +245,7 @@ namespace Microsoft.DotNet.Cli.Utils
                     File.Delete(tempDepsFile);
                 }
                 catch (Exception e2)
-                { 
+                {
                     Reporter.Verbose.WriteLine($"unable to delete temporary deps.json file: {e2.Message}");
                 }
             }

src/Microsoft.DotNet.Cli.Utils/CommandResolution/RootedCommandResolver.cs

@@ -1,13 +1,4 @@
-using System;
+using System.IO;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {

src/Microsoft.DotNet.Cli.Utils/CommandResolution/ScriptCommandResolverPolicy.cs

@@ -1,13 +1,4 @@
-using System;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -18,7 +9,7 @@ namespace Microsoft.DotNet.Cli.Utils
             var environment = new EnvironmentProvider();
 
             var platformCommandSpecFactory = default(IPlatformCommandSpecFactory);
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
                 platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
             }

src/Microsoft.DotNet.Cli.Utils/CommandResolution/WindowsExePreferredCommandSpecFactory.cs

@@ -2,12 +2,6 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
-using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -36,7 +30,7 @@ namespace Microsoft.DotNet.Cli.Utils
                 }
             }
 
-            return useCmdWrapper 
+            return useCmdWrapper
                 ? CreateCommandSpecWrappedWithCmd(commandPath, args, resolutionStrategy)
                 : CreateCommandSpecFromExecutable(commandPath, args, resolutionStrategy);
         }

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

@@ -1,24 +1,18 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
-using NuGet.Packaging;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
     internal static class CommandResolver
     {
         public static CommandSpec TryResolveCommandSpec(
-            string commandName, 
+            string commandName,
-            IEnumerable<string> args, 
+            IEnumerable<string> args,
-            NuGetFramework framework = null, 
+            NuGetFramework framework = null,
-            string configuration=Constants.DefaultConfiguration, 
+            string configuration = Constants.DefaultConfiguration,
-            string outputPath=null)
+            string outputPath = null)
         {
             var commandResolverArgs = new CommandResolverArguments
             {
@@ -29,16 +23,16 @@ namespace Microsoft.DotNet.Cli.Utils
                 Configuration = configuration,
                 OutputPath = outputPath
             };
-            
+
             var defaultCommandResolver = DefaultCommandResolverPolicy.Create();
-            
+
             return defaultCommandResolver.Resolve(commandResolverArgs);
         }
-        
+
         public static CommandSpec TryResolveScriptCommandSpec(
-            string commandName, 
+            string commandName,
-            IEnumerable<string> args, 
+            IEnumerable<string> args,
-            Project project, 
+            Project project,
             string[] inferredExtensionList)
         {
             var commandResolverArgs = new CommandResolverArguments
@@ -50,7 +44,7 @@ namespace Microsoft.DotNet.Cli.Utils
             };
 
             var scriptCommandResolver = ScriptCommandResolverPolicy.Create();
-            
+
             return scriptCommandResolver.Resolve(commandResolverArgs);
         }
     }

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

@@ -1,13 +1,13 @@
 // 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 Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
     public static class Constants
     {
-        private static Platform CurrentPlatform => PlatformServices.Default.Runtime.OperatingSystemPlatform;
+        private static Platform CurrentPlatform => RuntimeEnvironment.OperatingSystemPlatform;
         public const string DefaultConfiguration = "Debug";
 
         public static readonly string ProjectFileName = "project.json";

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

@@ -1,7 +1,5 @@
 using System;
 using System.IO;
-using System.Reflection;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {

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

@@ -4,7 +4,7 @@
 using System;
 using System.IO;
 using System.Reflection;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -22,7 +22,7 @@ namespace Microsoft.DotNet.Cli.Utils
         {
             var content = File.ReadAllText(DotnetFiles.VersionFile);
             content += Environment.NewLine;
-            content += PlatformServices.Default.Runtime.GetRuntimeIdentifier();
+            content += RuntimeEnvironment.GetRuntimeIdentifier();
             return content;
         }
     }

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

@@ -1,9 +1,4 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {

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

@@ -2,8 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
+using Microsoft.DotNet.InternalAbstractions;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -19,7 +18,7 @@ namespace Microsoft.DotNet.Cli.Utils
                 if (_executableExtensions == null)
                 {
 
-                    _executableExtensions = PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows
+                    _executableExtensions = RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows
                         ? Environment.GetEnvironmentVariable("PATHEXT")
                             .Split(';')
                             .Select(e => e.ToLower().Trim('"'))
@@ -36,7 +35,7 @@ namespace Microsoft.DotNet.Cli.Utils
             {
                 if (_searchPaths == null)
                 {
-                    var searchPaths = new List<string> { PlatformServices.Default.Application.ApplicationBasePath };
+                    var searchPaths = new List<string> { ApplicationEnvironment.ApplicationBasePath };
 
                     searchPaths.AddRange(Environment
                         .GetEnvironmentVariable("PATH")

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

@@ -1,9 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {

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

@@ -1,7 +1,5 @@
 using System;
 using System.IO;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Diagnostics;
 using System.Reflection;
 
 namespace Microsoft.DotNet.Cli.Utils

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

@@ -3,7 +3,7 @@
 
 using System;
 using System.IO;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Tools.Common
 {
@@ -98,7 +98,7 @@ namespace Microsoft.DotNet.Tools.Common
             }
 
             StringComparison compare;
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
                 compare = StringComparison.OrdinalIgnoreCase;
                 // check if paths are on the same volume
@@ -216,7 +216,7 @@ namespace Microsoft.DotNet.Tools.Common
         {
             var comparison = StringComparison.Ordinal;
 
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
                 comparison = StringComparison.OrdinalIgnoreCase;
             }

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

@@ -2,7 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System.Collections.Generic;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.Cli.Utils
@@ -100,7 +100,7 @@ namespace Microsoft.DotNet.Cli.Utils
             if (framework.IsDesktop())
             {
                 IPlatformCommandSpecFactory platformCommandSpecFactory = null;
-                if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+                if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
                 {
                     platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
                 }

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

@@ -1,9 +1,6 @@
 // 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 Microsoft.Extensions.PlatformAbstractions;
-
 namespace Microsoft.DotNet.Cli.Utils
 {
     // Stupid-simple console manager

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

@@ -1,10 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using Microsoft.DotNet.Cli.Utils.CommandParsing;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Cli.Utils
 {
@@ -48,7 +47,7 @@ namespace Microsoft.DotNet.Cli.Utils
 
         private static string[] DetermineInferredScriptExtensions()
         {
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
                 return new string[] { "", ".cmd" };
             }

src/Microsoft.DotNet.InternalAbstractions/ApplicationEnvironment.cs

@@ -0,0 +1,25 @@
+// 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.IO;
+
+namespace Microsoft.DotNet.InternalAbstractions
+{
+    public static class ApplicationEnvironment
+    {
+        public static string ApplicationBasePath { get; } = GetApplicationBasePath();
+
+        private static string GetApplicationBasePath()
+        {
+            var basePath =
+#if NET451
+                (string)AppDomain.CurrentDomain.GetData("APP_CONTEXT_BASE_DIRECTORY") ??
+                AppDomain.CurrentDomain.BaseDirectory;
+#else
+                AppContext.BaseDirectory;
+#endif
+            return Path.GetFullPath(basePath);
+        }
+    }
+}

src/Microsoft.DotNet.InternalAbstractions/Native/NativeMethods.Darwin.cs

@@ -0,0 +1,55 @@
+// 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;
+
+namespace Microsoft.DotNet.InternalAbstractions.Native
+{
+    internal static partial class NativeMethods
+    {
+        public static class Darwin
+        {
+            private const int CTL_KERN = 1;
+            private const int KERN_OSRELEASE = 2;
+
+            public unsafe static string GetKernelRelease()
+            {
+                const uint BUFFER_LENGTH = 32;
+
+                var name = stackalloc int[2];
+                name[0] = CTL_KERN;
+                name[1] = KERN_OSRELEASE;
+
+                var buf = stackalloc byte[(int)BUFFER_LENGTH];
+                var len = stackalloc uint[1];
+                *len = BUFFER_LENGTH;
+
+                try
+                {
+                    // If the buffer isn't big enough, it seems sysctl still returns 0 and just sets len to the
+                    // necessary buffer size. This appears to be contrary to the man page, but it's easy to detect
+                    // by simply checking len against the buffer length.
+                    if (sysctl(name, 2, buf, len, IntPtr.Zero, 0) == 0 && *len < BUFFER_LENGTH)
+                    {
+                        return Marshal.PtrToStringAnsi((IntPtr)buf, (int)*len);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    throw new PlatformNotSupportedException("Error reading Darwin Kernel Version", ex);
+                }
+                throw new PlatformNotSupportedException("Unknown error reading Darwin Kernel Version");
+            }
+
+            [DllImport("libc")]
+            private unsafe static extern int sysctl(
+                int* name,
+                uint namelen,
+                byte* oldp,
+                uint* oldlenp,
+                IntPtr newp,
+                uint newlen);
+        }
+    }
+}

src/Microsoft.DotNet.InternalAbstractions/Native/NativeMethods.Unix.cs

@@ -0,0 +1,39 @@
+// 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.
+
+#if NET451
+
+using System;
+using System.Runtime.InteropServices;
+
+namespace Microsoft.DotNet.InternalAbstractions.Native
+{
+    internal static partial class NativeMethods
+    {
+        public static class Unix
+        {
+            public unsafe static string GetUname()
+            {
+                // Utsname shouldn't be larger than 2K
+                var buf = stackalloc byte[2048];
+
+                try
+                {
+                    if (uname((IntPtr)buf) == 0)
+                    {
+                        return Marshal.PtrToStringAnsi((IntPtr)buf);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    throw new PlatformNotSupportedException("Error reading Unix name", ex);
+                }
+                throw new PlatformNotSupportedException("Unknown error reading Unix name");
+            }
+
+            [DllImport("libc")]
+            private static extern int uname(IntPtr utsname);
+        }
+    }
+}
+#endif

src/Microsoft.DotNet.InternalAbstractions/Native/NativeMethods.Windows.cs

@@ -0,0 +1,43 @@
+// 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.Runtime.InteropServices;
+
+namespace Microsoft.DotNet.InternalAbstractions.Native
+{
+    internal static partial class NativeMethods
+    {
+        public static class Windows
+        {
+            [StructLayout(LayoutKind.Sequential)]
+            internal struct RTL_OSVERSIONINFOEX
+            {
+                internal uint dwOSVersionInfoSize;
+                internal uint dwMajorVersion;
+                internal uint dwMinorVersion;
+                internal uint dwBuildNumber;
+                internal uint dwPlatformId;
+                [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
+                internal string szCSDVersion;
+            }
+
+            // This call avoids the shimming Windows does to report old versions
+            [DllImport("ntdll")]
+            private static extern int RtlGetVersion(out RTL_OSVERSIONINFOEX lpVersionInformation);
+
+            internal static string RtlGetVersion()
+            {
+                RTL_OSVERSIONINFOEX osvi = new RTL_OSVERSIONINFOEX();
+                osvi.dwOSVersionInfoSize = (uint)Marshal.SizeOf(osvi);
+                if (RtlGetVersion(out osvi) == 0)
+                {
+                    return $"{osvi.dwMajorVersion}.{osvi.dwMinorVersion}.{osvi.dwBuildNumber}";
+                }
+                else
+                {
+                    return null;
+                }
+            }
+        }
+    }
+}

src/Microsoft.DotNet.InternalAbstractions/Native/PlatformApis.cs

@@ -0,0 +1,171 @@
+// 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.IO;
+using System.Runtime.InteropServices;
+
+namespace Microsoft.DotNet.InternalAbstractions.Native
+{
+    internal static class PlatformApis
+    {
+        private class DistroInfo
+        {
+            public string Id;
+            public string VersionId;
+        }
+
+        private static readonly Lazy<Platform> _platform = new Lazy<Platform>(DetermineOSPlatform);
+        private static readonly Lazy<DistroInfo> _distroInfo = new Lazy<DistroInfo>(LoadDistroInfo);
+
+        public static string GetOSName()
+        {
+            switch (GetOSPlatform())
+            {
+                case Platform.Windows:
+                    return "Windows";
+                case Platform.Linux:
+                    return GetDistroId() ?? "Linux";
+                case Platform.Darwin:
+                    return "Mac OS X";
+                default:
+                    return "Unknown";
+            }
+        }
+
+        public static string GetOSVersion()
+        {
+            switch (GetOSPlatform())
+            {
+                case Platform.Windows:
+                    return NativeMethods.Windows.RtlGetVersion() ?? string.Empty;
+                case Platform.Linux:
+                    return GetDistroVersionId() ?? string.Empty;
+                case Platform.Darwin:
+                    return GetDarwinVersion() ?? string.Empty;
+                default:
+                    return string.Empty;
+            }
+        }
+
+        private static string GetDarwinVersion()
+        {
+            Version version;
+            var kernelRelease = NativeMethods.Darwin.GetKernelRelease();
+            if (!Version.TryParse(kernelRelease, out version) || version.Major < 5)
+            {
+                // 10.0 covers all versions prior to Darwin 5
+                // Similarly, if the version is not a valid version number, but we have still detected that it is Darwin, we just assume
+                // it is OS X 10.0
+                return "10.0";
+            }
+            else
+            {
+                // Mac OS X 10.1 mapped to Darwin 5.x, and the mapping continues that way
+                // So just subtract 4 from the Darwin version.
+                // https://en.wikipedia.org/wiki/Darwin_%28operating_system%29
+                return $"10.{version.Major - 4}";
+            }
+        }
+
+        public static Platform GetOSPlatform()
+        {
+            return _platform.Value;
+        }
+
+        private static string GetDistroId()
+        {
+            return _distroInfo.Value?.Id;
+        }
+
+        private static string GetDistroVersionId()
+        {
+            return _distroInfo.Value?.VersionId;
+        }
+
+        private static DistroInfo LoadDistroInfo()
+        {
+            // Sample os-release file:
+            //   NAME="Ubuntu"
+            //   VERSION = "14.04.3 LTS, Trusty Tahr"
+            //   ID = ubuntu
+            //   ID_LIKE = debian
+            //   PRETTY_NAME = "Ubuntu 14.04.3 LTS"
+            //   VERSION_ID = "14.04"
+            //   HOME_URL = "http://www.ubuntu.com/"
+            //   SUPPORT_URL = "http://help.ubuntu.com/"
+            //   BUG_REPORT_URL = "http://bugs.launchpad.net/ubuntu/"
+            // We use ID and VERSION_ID
+
+            if (File.Exists("/etc/os-release"))
+            {
+                var lines = File.ReadAllLines("/etc/os-release");
+                var result = new DistroInfo();
+                foreach (var line in lines)
+                {
+                    if (line.StartsWith("ID=", StringComparison.Ordinal))
+                    {
+                        result.Id = line.Substring(3).Trim('"', '\'');
+                    }
+                    else if (line.StartsWith("VERSION_ID=", StringComparison.Ordinal))
+                    {
+                        result.VersionId = line.Substring(11).Trim('"', '\'');
+                    }
+                }
+                return result;
+            }
+            return null;
+        }
+
+        // I could probably have just done one method signature and put the #if inside the body but the implementations
+        // are just completely different so I wanted to make that clear by putting the whole thing inside the #if.
+#if NET451
+        private static Platform DetermineOSPlatform()
+        {
+            var platform = (int)Environment.OSVersion.Platform;
+            var isWindows = (platform != 4) && (platform != 6) && (platform != 128);
+
+            if (isWindows)
+            {
+                return Platform.Windows;
+            }
+            else
+            {
+                try
+                {
+                    var uname = NativeMethods.Unix.GetUname();
+                    if (string.Equals(uname, "Darwin", StringComparison.OrdinalIgnoreCase))
+                    {
+                        return Platform.Darwin;
+                    }
+                    if (string.Equals(uname, "Linux", StringComparison.OrdinalIgnoreCase))
+                    {
+                        return Platform.Linux;
+                    }
+                }
+                catch
+                {
+                }
+                return Platform.Unknown;
+            }
+        }
+#else
+        private static Platform DetermineOSPlatform()
+        {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                return Platform.Windows;
+            }
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+            {
+                return Platform.Linux;
+            }
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+            {
+                return Platform.Darwin;
+            }
+            return Platform.Unknown;
+        }
+#endif
+    }
+}

src/Microsoft.DotNet.InternalAbstractions/Platform.cs

@@ -0,0 +1,13 @@
+// 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.
+
+namespace Microsoft.DotNet.InternalAbstractions
+{
+    public enum Platform
+    {
+        Unknown = 0,
+        Windows = 1,
+        Linux = 2,
+        Darwin = 3
+    }
+}

src/Microsoft.DotNet.InternalAbstractions/RuntimeEnvironment.cs

@@ -0,0 +1,104 @@
+// 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 Microsoft.DotNet.InternalAbstractions.Native;
+
+namespace Microsoft.DotNet.InternalAbstractions
+{
+    public static class RuntimeEnvironment
+    {
+        private static readonly string OverrideEnvironmentVariableName = "DOTNET_RUNTIME_ID";
+
+        public static Platform OperatingSystemPlatform { get; } = PlatformApis.GetOSPlatform();
+
+        public static string OperatingSystemVersion { get; } = PlatformApis.GetOSVersion();
+
+        public static string OperatingSystem { get; } = PlatformApis.GetOSName();
+
+        public static string RuntimeArchitecture { get; } = GetArch();
+
+        private static string GetArch()
+        {
+#if NET451
+            return Environment.Is64BitProcess ? "x64" : "x86";
+#else
+            return IntPtr.Size == 8 ? "x64" : "x86";
+#endif
+        }
+
+        public static string GetRuntimeIdentifier()
+        {
+            return
+                Environment.GetEnvironmentVariable(OverrideEnvironmentVariableName) ??
+                (GetRIDOS() + GetRIDVersion() + GetRIDArch());
+        }
+
+        private static string GetRIDArch()
+        {
+            if (!string.IsNullOrEmpty(RuntimeArchitecture))
+            {
+                return $"-{RuntimeArchitecture.ToLowerInvariant()}";
+            }
+            return string.Empty;
+        }
+
+        private static string GetRIDVersion()
+        {
+            // Windows RIDs do not separate OS name and version by "." due to legacy
+            // Others do, that's why we have the "." prefix on them below
+            switch (OperatingSystemPlatform)
+            {
+                case Platform.Windows:
+                    return GetWindowsProductVersion();
+                case Platform.Linux:
+                    return $".{OperatingSystemVersion}";
+                case Platform.Darwin:
+                    return $".{OperatingSystemVersion}";
+                default:
+                    return string.Empty; // Unknown Platform? Unknown Version!
+            }
+        }
+
+        private static string GetWindowsProductVersion()
+        {
+            var ver = Version.Parse(OperatingSystemVersion);
+            if (ver.Major == 6)
+            {
+                if (ver.Minor == 1)
+                {
+                    return "7";
+                }
+                else if (ver.Minor == 2)
+                {
+                    return "8";
+                }
+                else if (ver.Minor == 3)
+                {
+                    return "81";
+                }
+            }
+            else if (ver.Major == 10 && ver.Minor == 0)
+            {
+                // Not sure if there will be  10.x (where x > 0) or even 11, so let's be defensive.
+                return "10";
+            }
+            return string.Empty; // Unknown version
+        }
+
+        private static string GetRIDOS()
+        {
+            switch (OperatingSystemPlatform)
+            {
+                case Platform.Windows:
+                    return "win";
+                case Platform.Linux:
+                    return OperatingSystem.ToLowerInvariant();
+                case Platform.Darwin:
+                    return "osx";
+                default:
+                    return "unknown";
+            }
+        }
+    }
+}

src/Microsoft.DotNet.InternalAbstractions/project.json

@@ -7,14 +7,23 @@
   },
   "compilationOptions": {
     "warningsAsErrors": true,
-    "keyFile": "../../tools/Key.snk"
+    "keyFile": "../../tools/Key.snk",
-  },
+    "allowUnsafe": true
-  "dependencies": {
-    "Microsoft.Extensions.PlatformAbstractions": "1.0.0-rc2-20581"
   },
   "frameworks": {
-    "net451": {},
+    "net451": { },
-    "netstandard1.3": {}
+    "netstandard1.3": {
+      "dependencies": {
+        "System.AppContext": "4.1.0-rc2-24027",
+        "System.Collections": "4.0.11-rc2-24027",
+        "System.IO": "4.1.0-rc2-24027",
+        "System.IO.FileSystem": "4.0.1-rc2-24027",
+        "System.Reflection.TypeExtensions": "4.1.0-rc2-24027",
+        "System.Runtime.Extensions": "4.1.0-rc2-24027",
+        "System.Runtime.InteropServices": "4.1.0-rc2-24027",
+        "System.Runtime.InteropServices.RuntimeInformation": "4.0.0-rc2-24027"
+      }
+    }
   },
-  "scripts": {}
+  "scripts": { }
 }

src/Microsoft.DotNet.ProjectModel.Workspaces/ProjectJsonWorkspace.cs

@@ -12,9 +12,9 @@ using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Text;
 using Microsoft.DotNet.Cli.Compiler.Common;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel.Compilation;
 using Microsoft.DotNet.ProjectModel.Files;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.ProjectModel.Workspaces
@@ -225,7 +225,7 @@ namespace Microsoft.DotNet.ProjectModel.Workspaces
             {
                 keyFile = Path.GetFullPath(Path.Combine(projectDirectory, compilerOptions.KeyFile));
 
-                if (PlatformServices.Default.Runtime.OperatingSystemPlatform != Extensions.PlatformAbstractions.Platform.Windows || useOssSigning)
+                if (RuntimeEnvironment.OperatingSystemPlatform != InternalAbstractions.Platform.Windows || useOssSigning)
                 {
                     return options.WithCryptoPublicKey(
                         SnkUtils.ExtractPublicKey(File.ReadAllBytes(keyFile)));

src/Microsoft.DotNet.ProjectModel/FileNameSuffixes.cs

@@ -1,5 +1,5 @@
 using System;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.ProjectModel
 {
@@ -13,7 +13,7 @@ namespace Microsoft.DotNet.ProjectModel
         {
             get
             {
-                switch (PlatformServices.Default.Runtime.OperatingSystemPlatform)
+                switch (RuntimeEnvironment.OperatingSystemPlatform)
                 {
                     case Platform.Windows:
                         return Windows;

src/Microsoft.DotNet.ProjectModel/ProjectContextBuilder.cs

@@ -6,10 +6,10 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel.Graph;
 using Microsoft.DotNet.ProjectModel.Resolution;
 using Microsoft.Extensions.Internal;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.ProjectModel
@@ -267,7 +267,7 @@ namespace Microsoft.DotNet.ProjectModel
             {
                 // we got a ridless target for desktop so turning portable mode on
                 isPortable = true;
-                var legacyRuntime = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+                var legacyRuntime = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
                 if (RuntimeIdentifiers.Contains(legacyRuntime))
                 {
                     runtime = legacyRuntime;

src/Microsoft.DotNet.ProjectModel/Resolution/FrameworkReferenceResolver.cs

@@ -7,11 +7,10 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Runtime.Versioning;
-using System.Threading.Tasks;
 using System.Xml.Linq;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel.Utilities;
 using Microsoft.Extensions.DependencyModel.Resolution;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.ProjectModel.Resolution
@@ -63,7 +62,7 @@ namespace Microsoft.DotNet.ProjectModel.Resolution
                 return referenceAssembliesPath;
             }
 
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform != Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
                 // There is no reference assemblies path outside of windows
                 // The environment variable can be used to specify one
@@ -210,7 +209,7 @@ namespace Microsoft.DotNet.ProjectModel.Resolution
         private static FrameworkInformation GetFrameworkInformation(NuGetFramework targetFramework, string referenceAssembliesPath)
         {
             // Check for legacy frameworks
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows &&
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows &&
                 targetFramework.IsDesktop() &&
                 targetFramework.Version <= new Version(3, 5, 0, 0))
             {

src/Microsoft.DotNet.ProjectModel/RuntimeEnvironmentRidExtensions.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Microsoft.Extensions.PlatformAbstractions
+namespace Microsoft.DotNet.InternalAbstractions
 {
     // This is to support some legacy stuff.
     // dnu restore (and thus dotnet restore) always uses win7-x64 as the Windows restore target,
@@ -12,11 +12,11 @@ namespace Microsoft.Extensions.PlatformAbstractions
     public static class RuntimeEnvironmentRidExtensions
     {
         // Work around NuGet/Home#1941
-        public static IEnumerable<string> GetOverrideRestoreRuntimeIdentifiers(this IRuntimeEnvironment env)
+        public static IEnumerable<string> GetOverrideRestoreRuntimeIdentifiers()
         {
-            if (env.OperatingSystemPlatform != Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
-                yield return env.GetRuntimeIdentifier();
+                yield return RuntimeEnvironment.GetRuntimeIdentifier();
             }
             else
             {
@@ -26,44 +26,44 @@ namespace Microsoft.Extensions.PlatformAbstractions
         }
 
         // Gets the identfier that is used for restore by default (this is different from the actual RID, but only on Windows)
-        public static string GetLegacyRestoreRuntimeIdentifier(this IRuntimeEnvironment env)
+        public static string GetLegacyRestoreRuntimeIdentifier()
         {
-            if (env.OperatingSystemPlatform != Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
-                return env.GetRuntimeIdentifier();
+                return RuntimeEnvironment.GetRuntimeIdentifier();
             }
             else
             {
-                var arch = env.RuntimeArchitecture.ToLowerInvariant();
+                var arch = RuntimeEnvironment.RuntimeArchitecture.ToLowerInvariant();
                 return "win7-" + arch;
             }
         }
 
-        public static IEnumerable<string> GetAllCandidateRuntimeIdentifiers(this IRuntimeEnvironment env)
+        public static IEnumerable<string> GetAllCandidateRuntimeIdentifiers()
         {
-            if (env.OperatingSystemPlatform != Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
-                yield return env.GetRuntimeIdentifier();
+                yield return RuntimeEnvironment.GetRuntimeIdentifier();
             }
             else
             {
-                var arch = env.RuntimeArchitecture.ToLowerInvariant();
+                var arch = RuntimeEnvironment.RuntimeArchitecture.ToLowerInvariant();
-                if (env.OperatingSystemVersion.StartsWith("6.1", StringComparison.Ordinal))
+                if (RuntimeEnvironment.OperatingSystemVersion.StartsWith("6.1", StringComparison.Ordinal))
                 {
                     yield return "win7-" + arch;
                 }
-                else if (env.OperatingSystemVersion.StartsWith("6.2", StringComparison.Ordinal))
+                else if (RuntimeEnvironment.OperatingSystemVersion.StartsWith("6.2", StringComparison.Ordinal))
                 {
                     yield return "win8-" + arch;
                     yield return "win7-" + arch;
                 }
-                else if (env.OperatingSystemVersion.StartsWith("6.3", StringComparison.Ordinal))
+                else if (RuntimeEnvironment.OperatingSystemVersion.StartsWith("6.3", StringComparison.Ordinal))
                 {
                     yield return "win81-" + arch;
                     yield return "win8-" + arch;
                     yield return "win7-" + arch;
                 }
-                else if (env.OperatingSystemVersion.StartsWith("10.0", StringComparison.Ordinal))
+                else if (RuntimeEnvironment.OperatingSystemVersion.StartsWith("10.0", StringComparison.Ordinal))
                 {
                     yield return "win10-" + arch;
                     yield return "win81-" + arch;

src/Microsoft.DotNet.ProjectModel/Utilities/PathUtility.cs

@@ -3,7 +3,7 @@
 
 using System;
 using System.IO;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.ProjectModel.Utilities
 {
@@ -84,7 +84,7 @@ namespace Microsoft.DotNet.ProjectModel.Utilities
             }
 
             StringComparison compare;
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
                 compare = StringComparison.OrdinalIgnoreCase;
                 // check if paths are on the same volume

src/Microsoft.Extensions.DependencyModel/DependencyContext.cs

@@ -2,11 +2,9 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
-using System.IO;
-using System.Reflection;
 using System.Collections.Generic;
 using System.Linq;
-using Microsoft.Extensions.PlatformAbstractions;
+using System.Reflection;
 
 namespace Microsoft.Extensions.DependencyModel
 {

src/Microsoft.Extensions.DependencyModel/DependencyContextWriter.cs

@@ -6,7 +6,6 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
-using Microsoft.Extensions.PlatformAbstractions;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 

src/Microsoft.Extensions.DependencyModel/Resolution/AppBaseCompilationAssemblyResolver.cs

@@ -4,8 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Reflection;
+using Microsoft.DotNet.InternalAbstractions;
-using Microsoft.Extensions.PlatformAbstractions;
 using Microsoft.Extensions.EnvironmentAbstractions;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
@@ -25,7 +24,7 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
         }
 
         internal AppBaseCompilationAssemblyResolver(IFileSystem fileSystem)
-            : this(fileSystem, PlatformServices.Default.Application.ApplicationBasePath)
+            : this(fileSystem, ApplicationEnvironment.ApplicationBasePath)
         {
         }
 

src/Microsoft.Extensions.DependencyModel/Resolution/DotNetReferenceAssembliesPathResolver.cs

@@ -1,10 +1,8 @@
 // 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 Microsoft.DotNet.InternalAbstractions;
-using System.IO;
 using Microsoft.Extensions.EnvironmentAbstractions;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
 {
@@ -12,7 +10,7 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
     {
         public static readonly string DotNetReferenceAssembliesPathEnv = "DOTNET_REFERENCE_ASSEMBLIES_PATH";
 
-        internal static string Resolve(IEnvironment envirnment, IFileSystem fileSystem, IRuntimeEnvironment runtimeEnvironment)
+        internal static string Resolve(IEnvironment envirnment, IFileSystem fileSystem)
         {
             var path = envirnment.GetEnvironmentVariable(DotNetReferenceAssembliesPathEnv);
             if (!string.IsNullOrEmpty(path))
@@ -20,17 +18,17 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
                 return path;
             }
 
-            return GetDefaultDotNetReferenceAssembliesPath(fileSystem, runtimeEnvironment);
+            return GetDefaultDotNetReferenceAssembliesPath(fileSystem);
         }
 
         public static string Resolve()
         {
-            return Resolve(EnvironmentWrapper.Default, FileSystemWrapper.Default, PlatformServices.Default.Runtime);
+            return Resolve(EnvironmentWrapper.Default, FileSystemWrapper.Default);
         }
 
-        private static string GetDefaultDotNetReferenceAssembliesPath(IFileSystem fileSystem, IRuntimeEnvironment runtimeEnvironment)
+        private static string GetDefaultDotNetReferenceAssembliesPath(IFileSystem fileSystem)
         {
-            var os = runtimeEnvironment.OperatingSystemPlatform;
+            var os = RuntimeEnvironment.OperatingSystemPlatform;
 
             if (os == Platform.Windows)
             {

src/Microsoft.Extensions.DependencyModel/Resolution/PackageCompilationAssemblyResolver.cs

@@ -4,7 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.Extensions.EnvironmentAbstractions;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
@@ -15,7 +15,7 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
         private readonly string _nugetPackageDirectory;
 
         public PackageCompilationAssemblyResolver()
-            : this(EnvironmentWrapper.Default, PlatformServices.Default.Runtime, FileSystemWrapper.Default)
+            : this(EnvironmentWrapper.Default, FileSystemWrapper.Default)
         {
         }
 
@@ -25,9 +25,8 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
         }
 
         internal PackageCompilationAssemblyResolver(IEnvironment environment,
-            IRuntimeEnvironment runtimeEnvironment,
             IFileSystem fileSystem)
-            : this(fileSystem, GetDefaultPackageDirectory(runtimeEnvironment, environment))
+            : this(fileSystem, GetDefaultPackageDirectory(environment))
         {
         }
 
@@ -37,7 +36,10 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
             _nugetPackageDirectory = nugetPackageDirectory;
         }
 
-        internal static string GetDefaultPackageDirectory(IRuntimeEnvironment runtimeEnvironment, IEnvironment environment)
+        private static string GetDefaultPackageDirectory(IEnvironment environment) => 
+            GetDefaultPackageDirectory(RuntimeEnvironment.OperatingSystemPlatform, environment);
+
+        internal static string GetDefaultPackageDirectory(Platform osPlatform, IEnvironment environment)
         {
             var packageDirectory = environment.GetEnvironmentVariable("NUGET_PACKAGES");
 
@@ -47,7 +49,7 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
             }
 
             string basePath;
-            if (runtimeEnvironment.OperatingSystemPlatform == Platform.Windows)
+            if (osPlatform == Platform.Windows)
             {
                 basePath = environment.GetEnvironmentVariable("USERPROFILE");
             }

src/Microsoft.Extensions.DependencyModel/Resolution/ReferenceAssemblyPathResolver.cs

@@ -4,7 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.Extensions.EnvironmentAbstractions;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
@@ -16,7 +16,7 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
         private readonly string[] _fallbackSearchPaths;
 
         public ReferenceAssemblyPathResolver()
-            : this(FileSystemWrapper.Default, PlatformServices.Default.Runtime, EnvironmentWrapper.Default)
+            : this(FileSystemWrapper.Default, EnvironmentWrapper.Default)
         {
         }
 
@@ -25,10 +25,10 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
         {
         }
 
-        internal ReferenceAssemblyPathResolver(IFileSystem fileSystem, IRuntimeEnvironment runtimeEnvironment, IEnvironment environment)
+        internal ReferenceAssemblyPathResolver(IFileSystem fileSystem, IEnvironment environment)
             : this(fileSystem,
-                GetDefaultReferenceAssembliesPath(runtimeEnvironment, fileSystem, environment),
+                GetDefaultReferenceAssembliesPath(fileSystem, RuntimeEnvironment.OperatingSystemPlatform, environment),
-                GetFallbackSearchPaths(fileSystem, runtimeEnvironment, environment))
+                GetFallbackSearchPaths(fileSystem, RuntimeEnvironment.OperatingSystemPlatform, environment))
         {
         }
 
@@ -85,9 +85,9 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
             return false;
         }
 
-        internal static string[] GetFallbackSearchPaths(IFileSystem fileSystem, IRuntimeEnvironment runtimeEnvironment, IEnvironment environment)
+        internal static string[] GetFallbackSearchPaths(IFileSystem fileSystem, Platform platform, IEnvironment environment)
         {
-            if (runtimeEnvironment.OperatingSystemPlatform != Platform.Windows)
+            if (platform != Platform.Windows)
             {
                 return new string[0];
             }
@@ -101,16 +101,16 @@ namespace Microsoft.Extensions.DependencyModel.Resolution
             return new[] { net20Dir };
         }
 
-        internal static string GetDefaultReferenceAssembliesPath(IRuntimeEnvironment runtimeEnvironment, IFileSystem fileSystem, IEnvironment environment)
+        internal static string GetDefaultReferenceAssembliesPath(IFileSystem fileSystem, Platform platform, IEnvironment environment)
         {
             // Allow setting the reference assemblies path via an environment variable
-            var referenceAssembliesPath = DotNetReferenceAssembliesPathResolver.Resolve(environment, fileSystem, runtimeEnvironment); 
+            var referenceAssembliesPath = DotNetReferenceAssembliesPathResolver.Resolve(environment, fileSystem); 
             if (!string.IsNullOrEmpty(referenceAssembliesPath))
             {
                 return referenceAssembliesPath;
             }
 
-            if (runtimeEnvironment.OperatingSystemPlatform != Platform.Windows)
+            if (platform != Platform.Windows)
             {
                 // There is no reference assemblies path outside of windows
                 // The environment variable can be used to specify one

src/Microsoft.Extensions.DependencyModel/project.json

@@ -26,7 +26,8 @@
       "imports": "portable-net45+wp80+win8+wpa81+dnxcore50",
       "dependencies": {
         "System.Diagnostics.Debug": "4.0.11-rc2-24027",
-        "System.Dynamic.Runtime": "4.0.11-rc2-24027"
+        "System.Dynamic.Runtime": "4.0.11-rc2-24027",
+        "System.Linq": "4.1.0-rc2-24027"
       }
     }
   },

src/Microsoft.Extensions.Testing.Abstractions/project.json

@@ -14,6 +14,7 @@
     "Newtonsoft.Json": "7.0.1",
     "Microsoft.DotNet.ProjectModel": "1.0.0-*",
     "Microsoft.Extensions.Logging.Abstractions": "1.0.0-rc2-20581",
+    "Microsoft.Extensions.PlatformAbstractions": "1.0.0-rc2-20581",
     "Microsoft.DiaSymReader": "1.0.6",
     "Microsoft.DiaSymReader.Native": "1.3.3"
   },

src/dotnet/Program.cs

@@ -7,6 +7,7 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel.Server;
 using Microsoft.DotNet.Tools.Build;
 using Microsoft.DotNet.Tools.Compiler;
@@ -17,7 +18,6 @@ using Microsoft.DotNet.Tools.Publish;
 using Microsoft.DotNet.Tools.Restore;
 using Microsoft.DotNet.Tools.Run;
 using Microsoft.DotNet.Tools.Test;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.Cli
@@ -186,12 +186,11 @@ namespace Microsoft.DotNet.Cli
             Reporter.Output.WriteLine($" Version:     {Product.Version}");
             Reporter.Output.WriteLine($" Commit Sha:  {commitSha}");
             Reporter.Output.WriteLine();
-            var runtimeEnvironment = PlatformServices.Default.Runtime;
             Reporter.Output.WriteLine("Runtime Environment:");
-            Reporter.Output.WriteLine($" OS Name:     {runtimeEnvironment.OperatingSystem}");
+            Reporter.Output.WriteLine($" OS Name:     {RuntimeEnvironment.OperatingSystem}");
-            Reporter.Output.WriteLine($" OS Version:  {runtimeEnvironment.OperatingSystemVersion}");
+            Reporter.Output.WriteLine($" OS Version:  {RuntimeEnvironment.OperatingSystemVersion}");
-            Reporter.Output.WriteLine($" OS Platform: {runtimeEnvironment.OperatingSystemPlatform}");
+            Reporter.Output.WriteLine($" OS Platform: {RuntimeEnvironment.OperatingSystemPlatform}");
-            Reporter.Output.WriteLine($" RID:         {runtimeEnvironment.GetRuntimeIdentifier()}");
+            Reporter.Output.WriteLine($" RID:         {RuntimeEnvironment.GetRuntimeIdentifier()}");
         }
 
         private static bool IsArg(string candidate, string longName)

src/dotnet/Telemetry.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using Microsoft.ApplicationInsights;
 using Microsoft.DotNet.Cli.Utils;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Diagnostics;
 
 namespace Microsoft.DotNet.Cli
 {
@@ -41,13 +41,13 @@ namespace Microsoft.DotNet.Cli
                     _client.InstrumentationKey = InstrumentationKey;
                     _client.Context.Session.Id = Guid.NewGuid().ToString();
 
-                    var runtimeEnvironment = PlatformServices.Default.Runtime;
+
-                    _client.Context.Device.OperatingSystem = runtimeEnvironment.OperatingSystem;
+                _client.Context.Device.OperatingSystem = RuntimeEnvironment.OperatingSystem;
 
                     _commonProperties = new Dictionary<string, string>();
-                    _commonProperties.Add(OSVersion, runtimeEnvironment.OperatingSystemVersion);
+                _commonProperties.Add(OSVersion, RuntimeEnvironment.OperatingSystemVersion);
-                    _commonProperties.Add(OSPlatform, runtimeEnvironment.OperatingSystemPlatform.ToString());
+                _commonProperties.Add(OSPlatform, RuntimeEnvironment.OperatingSystemPlatform.ToString());
-                    _commonProperties.Add(RuntimeId, runtimeEnvironment.GetRuntimeIdentifier());
+                _commonProperties.Add(RuntimeId, RuntimeEnvironment.GetRuntimeIdentifier());
                     _commonProperties.Add(ProductVersion, Product.Version);
                     _commonMeasurements = new Dictionary<string, double>();
                 }

src/dotnet/commands/dotnet-build/BuildCommandApp.cs

@@ -4,8 +4,8 @@
 using System.Collections.Generic;
 using Microsoft.DotNet.Cli.CommandLine;
 using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 // This class is responsible with defining the arguments for the Compile verb.
@@ -121,7 +121,7 @@ namespace Microsoft.DotNet.Tools.Compiler
                 IEnumerable<NuGetFramework> frameworks = null;
                 if (_frameworkOption.HasValue())
                 {
-                    frameworks = new [] { NuGetFramework.Parse(_frameworkOption.Value()) };
+                    frameworks = new[] { NuGetFramework.Parse(_frameworkOption.Value()) };
                 }
                 var success = execute(files, frameworks, this);
 
@@ -136,7 +136,7 @@ namespace Microsoft.DotNet.Tools.Compiler
             var rids = new List<string>();
             if (string.IsNullOrEmpty(RuntimeValue))
             {
-                return PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers();
+                return RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers();
             }
             else
             {

src/dotnet/commands/dotnet-build/DotnetProjectBuilder.cs

@@ -2,15 +2,12 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using Microsoft.DotNet.Cli;
 using Microsoft.DotNet.Cli.Compiler.Common;
 using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.Tools.Compiler;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Tools.Build
 {
@@ -23,7 +20,7 @@ namespace Microsoft.DotNet.Tools.Build
         private readonly DotNetCommandFactory _commandFactory;
         private readonly IncrementalManager _incrementalManager;
 
-        public DotNetProjectBuilder(BuildCommandApp args): base(args.ShouldSkipDependencies)
+        public DotNetProjectBuilder(BuildCommandApp args) : base(args.ShouldSkipDependencies)
         {
             _args = args;
 

src/dotnet/commands/dotnet-build/IncrementalManager.cs

@@ -7,12 +7,7 @@ using System.IO;
 using System.Linq;
 using Microsoft.DotNet.Cli.Compiler.Common;
 using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.ProjectModel.Utilities;
 using Microsoft.DotNet.Tools.Compiler;
-using Microsoft.Extensions.PlatformAbstractions;
-using Microsoft.DotNet.ProjectModel.Compilation;
-using NuGet.Protocol.Core.Types;
 
 namespace Microsoft.DotNet.Tools.Build
 {

src/dotnet/commands/dotnet-publish/PublishCommand.cs

@@ -8,13 +8,13 @@ using System.Linq;
 using Microsoft.DotNet.Cli.Compiler.Common;
 using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.Files;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.ProjectModel.Compilation;
 using Microsoft.DotNet.ProjectModel.Files;
 using Microsoft.DotNet.ProjectModel.Graph;
 using Microsoft.DotNet.ProjectModel.Utilities;
 using Microsoft.DotNet.Tools.Common;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.Tools.Publish
@@ -150,10 +150,10 @@ namespace Microsoft.DotNet.Tools.Publish
                 var runtimeAssetsToCopy = export.RuntimeAssets.Where(a => ShouldCopyExportRuntimeAsset(context, buildOutputPaths, export, a));
                 runtimeAssetsToCopy.StructuredCopyTo(outputPath, outputPaths.IntermediateOutputDirectoryPath);
 
-                foreach(var resourceAsset in export.ResourceAssemblies)
+                foreach (var resourceAsset in export.ResourceAssemblies)
                 {
                     var dir = Path.Combine(outputPath, resourceAsset.Locale);
-                    if(!Directory.Exists(dir))
+                    if (!Directory.Exists(dir))
                     {
                         Directory.CreateDirectory(dir);
                     }
@@ -291,7 +291,7 @@ namespace Microsoft.DotNet.Tools.Publish
             foreach (var dependency in dependencies)
             {
                 var export = exports[dependency.Name];
-                if(export.Library.Identity.Version.Equals(dependency.VersionRange.MinVersion))
+                if (export.Library.Identity.Version.Equals(dependency.VersionRange.MinVersion))
                 {
                     exclusionList.Add(export.Library.Identity.Name);
                     CollectDependencies(exports, export.Library.Dependencies, exclusionList);
@@ -454,7 +454,7 @@ namespace Microsoft.DotNet.Tools.Publish
                 contexts.Where(c => Equals(c.TargetFramework, framework));
 
             var rids = string.IsNullOrEmpty(runtime) ?
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers() :
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers() :
                 new[] { runtime };
 
             return contexts.Select(c => Workspace.GetRuntimeContext(c, rids));

src/dotnet/commands/dotnet-restore/Program.cs

@@ -5,13 +5,13 @@ using System;
 using System.Linq;
 using Microsoft.DotNet.Cli.CommandLine;
 using Microsoft.DotNet.Cli.Utils;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 
 namespace Microsoft.DotNet.Tools.Restore
 {
     public partial class RestoreCommand
     {
-        private static readonly string DefaultRid = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+        private static readonly string DefaultRid = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
 
         public static int Run(string[] args)
         {
@@ -28,7 +28,7 @@ namespace Microsoft.DotNet.Tools.Restore
             // "--verbosity" switch that goes BEFORE the command
             var quiet = args.Any(s => s.Equals("--quiet", StringComparison.OrdinalIgnoreCase));
             args = args.Where(s => !s.Equals("--quiet", StringComparison.OrdinalIgnoreCase)).ToArray();
-            
+
             app.OnExecute(() =>
             {
                 try

src/dotnet/commands/dotnet-run/RunCommand.cs

@@ -7,8 +7,8 @@ using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
 using NuGet.Frameworks;
 
 namespace Microsoft.DotNet.Tools.Run
@@ -70,7 +70,7 @@ namespace Microsoft.DotNet.Tools.Run
 
             var frameworkContexts = _workspace.GetProjectContextCollection(Project).FrameworkOnlyContexts;
 
-            var rids = PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers();
+            var rids = RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers();
 
             ProjectContext frameworkContext;
             if (Framework == null)

src/dotnet/commands/dotnet-test/Program.cs

@@ -6,8 +6,8 @@ using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Tools.Test
 {
@@ -44,7 +44,7 @@ namespace Microsoft.DotNet.Tools.Test
                 var projectPath = GetProjectPath(dotnetTestParams.ProjectPath);
                 var runtimeIdentifiers = !string.IsNullOrEmpty(dotnetTestParams.Runtime) ?
                     new[] { dotnetTestParams.Runtime } :
-                    PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers();
+                    RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers();
                 var exitCode = 0;
 
                 // Create a workspace

test/ArgumentForwardingTests/ArgumentForwardingTests.cs

@@ -11,7 +11,6 @@ using Xunit;
 using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
 using System.Diagnostics;
 using FluentAssertions;
 

test/EndToEnd/EndToEndTest.cs

@@ -5,10 +5,9 @@ using System;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
 using Xunit;
-using System.Diagnostics;
 
 namespace Microsoft.DotNet.Tests.EndToEnd
 {
@@ -152,7 +151,7 @@ namespace Microsoft.DotNet.Tests.EndToEnd
                 .Should()
                 .Pass();
         }
-        
+
         [Fact]
         public void TestDotnetPack()
         {
@@ -169,7 +168,7 @@ namespace Microsoft.DotNet.Tests.EndToEnd
             var publishCommand = new PublishCommand(TestProject, output: OutputDirectory);
             publishCommand.Execute().Should().Pass();
 
-            TestExecutable(OutputDirectory, publishCommand.GetPortableOutputName(), s_expectedOutput);    
+            TestExecutable(OutputDirectory, publishCommand.GetPortableOutputName(), s_expectedOutput);
         }
 
         [Fact]
@@ -196,7 +195,7 @@ namespace Microsoft.DotNet.Tests.EndToEnd
             TestProject = Path.Combine(TestDirectory, "project.json");
             OutputDirectory = Path.Combine(TestDirectory, s_outputdirName);
 
-            Rid = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+            Rid = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
         }
 
         private static void SetupStaticTestProject()
@@ -208,7 +207,7 @@ namespace Microsoft.DotNet.Tests.EndToEnd
             {
                 Directory.Delete(RestoredTestProjectDirectory, true);
             }
-            catch(Exception) {}
+            catch (Exception) { }
 
             Directory.CreateDirectory(RestoredTestProjectDirectory);
 
@@ -227,7 +226,7 @@ namespace Microsoft.DotNet.Tests.EndToEnd
         private bool IsNativeCompilationSupported()
         {
             bool isSupported = true;
-            var platform = PlatformServices.Default.Runtime.OperatingSystem.ToLower();
+            var platform = RuntimeEnvironment.OperatingSystem.ToLower();
             switch (platform)
             {
                 case "centos":

test/Microsoft.DotNet.Cli.Utils.Tests/GivenACompositeCommandResolver.cs

@@ -1,21 +1,11 @@
 // 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.Collections.Generic;
-using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
-using NuGet.Frameworks;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Moq;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {

test/Microsoft.DotNet.Cli.Utils.Tests/GivenADefaultCommandResolver.cs

@@ -1,21 +1,10 @@
 // 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.Collections.Generic;
-using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
 using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
-using NuGet.Frameworks;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAPathCommandResolver.cs

@@ -1,218 +0,0 @@
-// 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.Collections.Generic;
-using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
-using FluentAssertions;
-using NuGet.Frameworks;
-
-namespace Microsoft.DotNet.Cli.Utils.Tests
-{
-    public class GivenAPathCommandResolver
-    {
-        private static readonly string s_testDirectory = Path.Combine(AppContext.BaseDirectory, "pathTestDirectory");
-
-        [Fact]
-        public void It_returns_null_when_CommandName_is_null()
-        {
-            var pathCommandResolver = SetupPlatformPathCommandResolver();
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = null,
-                CommandArguments = null
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().BeNull();
-        }
-
-        [Fact]
-        public void It_returns_null_when_CommandName_does_not_exist_in_PATH()
-        {
-            var emptyPathEnvironmentMock = new Mock<IEnvironmentProvider>();
-            emptyPathEnvironmentMock.Setup(e => e
-                .GetCommandPath(It.IsAny<string>(), It.IsAny<string[]>()))
-                .Returns((string)null);
-
-            var pathCommandResolver = SetupPlatformPathCommandResolver(emptyPathEnvironmentMock.Object);
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = "nonexistent-command",
-                CommandArguments = null
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().BeNull();
-        }
-
-        [Fact]
-        public void It_returns_a_CommandSpec_with_CommandName_as_FileName_when_CommandName_exists_in_PATH()
-        {
-            var testCommandPath = CommandResolverTestUtils.CreateNonRunnableTestCommand(
-                s_testDirectory, 
-                "pathtestcommand1", 
-                ".exe");
-
-            var staticPathEnvironmentMock = new Mock<IEnvironmentProvider>();
-            staticPathEnvironmentMock.Setup(e => e
-                .GetCommandPath(It.IsAny<string>(), It.IsAny<string[]>()))
-                .Returns(testCommandPath); 
-
-            var pathCommandResolver = SetupPlatformPathCommandResolver(staticPathEnvironmentMock.Object, forceGeneric: true);
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = Path.GetFileNameWithoutExtension(testCommandPath),
-                CommandArguments = null
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().NotBeNull();
-
-            var commandFile = Path.GetFileNameWithoutExtension(result.Path);
-
-            commandFile.Should().Be(Path.GetFileNameWithoutExtension(testCommandPath));
-        }
-
-        [Fact]
-        public void It_escapes_CommandArguments_when_returning_a_CommandSpec()
-        {
-            var testCommandPath = CommandResolverTestUtils.CreateNonRunnableTestCommand(
-                s_testDirectory, 
-                "pathtestcommand1", 
-                ".exe");
-
-            var staticPathEnvironmentMock = new Mock<IEnvironmentProvider>();
-            staticPathEnvironmentMock.Setup(e => e
-                .GetCommandPath(It.IsAny<string>(), It.IsAny<string[]>()))
-                .Returns(testCommandPath); 
-
-            var pathCommandResolver = SetupPlatformPathCommandResolver(staticPathEnvironmentMock.Object, forceGeneric: true);
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = Path.GetFileNameWithoutExtension(testCommandPath),
-                CommandArguments = new [] {"arg with space"}
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().NotBeNull();
-            result.Args.Should().Be("\"arg with space\"");
-        }
-
-        [Fact]
-        public void It_returns_a_CommandSpec_with_Args_as_stringEmpty_when_returning_a_CommandSpec_and_CommandArguments_are_null()
-        {
-            var testCommandPath = CommandResolverTestUtils.CreateNonRunnableTestCommand(
-                s_testDirectory, 
-                "pathtestcommand1", 
-                ".exe");
-
-            var staticPathEnvironmentMock = new Mock<IEnvironmentProvider>();
-            staticPathEnvironmentMock.Setup(e => e
-                .GetCommandPath(It.IsAny<string>(), It.IsAny<string[]>()))
-                .Returns(testCommandPath); 
-
-            var pathCommandResolver = SetupPlatformPathCommandResolver(staticPathEnvironmentMock.Object, forceGeneric: true);
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = Path.GetFileNameWithoutExtension(testCommandPath),
-                CommandArguments = null
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().NotBeNull();
-            result.Args.Should().Be(string.Empty);
-        }
-
-        [Fact]
-        public void It_prefers_EXE_over_CMD_when_two_command_candidates_exist_and_using_WindowsExePreferredCommandSpecFactory()
-        {
-            var environment = new EnvironmentProvider(new [] {".exe", ".cmd"}, new[] { s_testDirectory });
-            var platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
-
-            var pathCommandResolver = new PathCommandResolver(environment, platformCommandSpecFactory);
-
-            CommandResolverTestUtils.CreateNonRunnableTestCommand(s_testDirectory, "extensionPreferenceCommand", ".exe");
-            CommandResolverTestUtils.CreateNonRunnableTestCommand(s_testDirectory, "extensionPreferenceCommand", ".cmd");
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = "extensionPreferenceCommand",
-                CommandArguments = null
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().NotBeNull();
-
-            var commandFile = Path.GetFileName(result.Path);
-            commandFile.Should().Be("extensionPreferenceCommand.exe");
-        }
-
-        [Fact]
-        public void It_wraps_command_with_CMD_EXE_when_command_has_CMD_Extension_and_using_WindowsExePreferredCommandSpecFactory()
-        {
-            var environment = new EnvironmentProvider(new [] {".cmd"}, new[] { s_testDirectory });
-            var platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
-
-            var pathCommandResolver = new PathCommandResolver(environment, platformCommandSpecFactory);
-
-            var testCommandPath = 
-                CommandResolverTestUtils.CreateNonRunnableTestCommand(s_testDirectory, "cmdWrapCommand", ".cmd");
-
-            var commandResolverArguments = new CommandResolverArguments()
-            {
-                CommandName = "cmdWrapCommand",
-                CommandArguments = null
-            };
-
-            var result = pathCommandResolver.Resolve(commandResolverArguments);
-
-            result.Should().NotBeNull();
-
-            var commandFile = Path.GetFileName(result.Path);
-            commandFile.Should().Be("cmd.exe");
-
-            result.Args.Should().Contain(testCommandPath);
-        }
-
-        private PathCommandResolver SetupPlatformPathCommandResolver(
-            IEnvironmentProvider environment = null, 
-            bool forceGeneric = false)
-        {
-            environment = environment ?? new EnvironmentProvider();
-
-            IPlatformCommandSpecFactory platformCommandSpecFactory = new GenericPlatformCommandSpecFactory();
-
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows
-                && !forceGeneric)
-            {
-                platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
-            }
-
-            var pathCommandResolver = new PathCommandResolver(environment, platformCommandSpecFactory);
-
-            return pathCommandResolver;
-        }
-    }
-}

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAProjectDependenciesCommandFactory.cs

@@ -1,22 +1,13 @@
 // 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.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using Microsoft.DotNet.TestFramework;
-using System.Threading;
 using FluentAssertions;
+using Microsoft.DotNet.ProjectModel;
+using Microsoft.DotNet.TestFramework;
+using Microsoft.DotNet.Tools.Test.Utilities;
 using NuGet.Frameworks;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAProjectDependencyCommandResolver.cs

@@ -2,27 +2,20 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
+using FluentAssertions;
-using System.Text;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
-using FluentAssertions;
 using NuGet.Frameworks;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {
     public class GivenAProjectDependenciesCommandResolver
     {
 
-        private static readonly string s_liveProjectDirectory = 
+        private static readonly string s_liveProjectDirectory =
             Path.Combine(AppContext.BaseDirectory, "TestAssets/TestProjects/AppWithDirectDependency");
 
         [Fact]
@@ -33,7 +26,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = null,
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = "/some/directory",
                 Configuration = "Debug",
                 Framework = FrameworkConstants.CommonFrameworks.NetCoreApp10
@@ -52,7 +45,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "command",
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = null,
                 Configuration = "Debug",
                 Framework = FrameworkConstants.CommonFrameworks.NetCoreApp10
@@ -71,7 +64,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "command",
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = s_liveProjectDirectory,
                 Configuration = "Debug",
                 Framework = null
@@ -90,7 +83,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "command",
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = s_liveProjectDirectory,
                 Configuration = null,
                 Framework = FrameworkConstants.CommonFrameworks.NetCoreApp10
@@ -153,7 +146,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "dotnet-hello",
-                CommandArguments = new [] { "arg with space"},
+                CommandArguments = new[] { "arg with space" },
                 ProjectDirectory = s_liveProjectDirectory,
                 Configuration = "Debug",
                 Framework = FrameworkConstants.CommonFrameworks.NetCoreApp10
@@ -203,7 +196,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var projectContext = ProjectContext.Create(
                 s_liveProjectDirectory,
                 FrameworkConstants.CommonFrameworks.NetCoreApp10,
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers());
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers());
 
             var depsFilePath =
                 projectContext.GetOutputPaths("Debug", outputPath: AppContext.BaseDirectory).RuntimeFiles.DepsJson;
@@ -232,7 +225,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var projectContext = ProjectContext.Create(
                 s_liveProjectDirectory,
                 FrameworkConstants.CommonFrameworks.NetCoreApp10,
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers());
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers());
 
             var depsFilePath =
                 projectContext.GetOutputPaths("Debug", AppContext.BaseDirectory).RuntimeFiles.DepsJson;
@@ -260,7 +253,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var result = projectDependenciesCommandResolver.Resolve(commandResolverArguments);
 
             result.Should().NotBeNull();
-            
+
             result.Args.Should().Contain("dotnet-hello");
         }
 

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAProjectPathCommandResolver.cs

@@ -2,20 +2,11 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
-using NuGet.Frameworks;
+using Microsoft.DotNet.InternalAbstractions;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {
@@ -31,7 +22,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = null,
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = "/some/directory"
             };
 
@@ -48,7 +39,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "command",
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = null
             };
 
@@ -130,7 +121,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "projectpathtestcommand1",
-                CommandArguments = new [] { "arg with space"},
+                CommandArguments = new[] { "arg with space" },
                 ProjectDirectory = s_testProjectDirectory
             };
 
@@ -143,7 +134,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
         [Fact]
         public void It_resolves_commands_with_extensions_defined_in_InferredExtensions()
         {
-            var extensions = new string[] {".sh", ".cmd", ".foo", ".exe"};
+            var extensions = new string[] { ".sh", ".cmd", ".foo", ".exe" };
             var projectPathCommandResolver = SetupPlatformProjectPathCommandResolver(forceGeneric: true);
 
             foreach (var extension in extensions)
@@ -166,7 +157,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
 
                 var commandFileName = Path.GetFileName(result.Path);
                 commandFileName.Should().Be("projectpathexttest" + extension);
-            }            
+            }
         }
 
         [Fact]
@@ -218,12 +209,12 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
 
         public void It_wraps_command_with_CMD_EXE_when_command_has_CMD_Extension_and_using_WindowsExePreferredCommandSpecFactory()
         {
-            var environment = new EnvironmentProvider(new [] {".cmd"});
+            var environment = new EnvironmentProvider(new[] { ".cmd" });
             var platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
 
             var pathCommandResolver = new PathCommandResolver(environment, platformCommandSpecFactory);
 
-            var testCommandPath = 
+            var testCommandPath =
                 CommandResolverTestUtils.CreateNonRunnableTestCommand(s_testProjectDirectory, "cmdWrapCommand", ".cmd");
 
             var commandResolverArguments = new CommandResolverArguments()
@@ -250,7 +241,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
 
             IPlatformCommandSpecFactory platformCommandSpecFactory = new GenericPlatformCommandSpecFactory();
 
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows
                 && !forceGeneric)
             {
                 platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAProjectToolsCommandResolver.cs

@@ -2,27 +2,15 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
 using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
+using Microsoft.DotNet.ProjectModel;
+using Microsoft.DotNet.ProjectModel.Graph;
+using Microsoft.DotNet.Tools.Test.Utilities;
 using NuGet.Frameworks;
 using NuGet.Versioning;
-using NuGet.ProjectModel;
+using Xunit;
-using Microsoft.DotNet.ProjectModel.Graph;
-using Microsoft.DotNet.ProjectModel.Compilation;
-using NuGet.ProjectModel;
-
-using LockFile = Microsoft.DotNet.ProjectModel.Graph.LockFile;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {
@@ -30,7 +18,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
     {
         private static readonly NuGetFramework s_toolPackageFramework = FrameworkConstants.CommonFrameworks.NetCoreApp10;
 
-        private static readonly string s_liveProjectDirectory = 
+        private static readonly string s_liveProjectDirectory =
             Path.Combine(AppContext.BaseDirectory, "TestAssets/TestProjects/AppWithToolDependency");
 
         [Fact]
@@ -41,7 +29,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = null,
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = "/some/directory"
             };
 
@@ -58,7 +46,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "command",
-                CommandArguments = new string[] {""},
+                CommandArguments = new string[] { "" },
                 ProjectDirectory = null
             };
 
@@ -115,7 +103,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "dotnet-portable",
-                CommandArguments = new [] { "arg with space"},
+                CommandArguments = new[] { "arg with space" },
                 ProjectDirectory = s_liveProjectDirectory
             };
 
@@ -140,7 +128,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var result = projectToolsCommandResolver.Resolve(commandResolverArguments);
 
             result.Should().NotBeNull();
-            
+
             var commandPath = result.Args.Trim('"');
             commandPath.Should().Contain("dotnet-portable.dll");
         }
@@ -163,8 +151,8 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var toolPathCalculator = new ToolPathCalculator(nugetPackagesRoot);
 
             var lockFilePath = toolPathCalculator.GetLockFilePath(
-                "dotnet-portable", 
+                "dotnet-portable",
-                new NuGetVersion("1.0.0"), 
+                new NuGetVersion("1.0.0"),
                 s_toolPackageFramework);
 
             var directory = Path.GetDirectoryName(lockFilePath);
@@ -181,7 +169,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var result = projectToolsCommandResolver.Resolve(commandResolverArguments);
             result.Should().NotBeNull();
 
-            
+
             depsJsonFile = Directory
                 .EnumerateFiles(directory)
                 .FirstOrDefault(p => Path.GetFileName(p).EndsWith(FileNameSuffixes.DepsJson));
@@ -198,8 +186,8 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var toolPathCalculator = new ToolPathCalculator(nugetPackagesRoot);
 
             var lockFilePath = toolPathCalculator.GetLockFilePath(
-                "dotnet-portable", 
+                "dotnet-portable",
-                new NuGetVersion("1.0.0"), 
+                new NuGetVersion("1.0.0"),
                 s_toolPackageFramework);
 
             var lockFile = LockFileReader.Read(lockFilePath, designTime: false);

test/Microsoft.DotNet.Cli.Utils.Tests/GivenARootedCommandResolver.cs

@@ -1,21 +1,9 @@
 // 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.Collections.Generic;
-using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
-using NuGet.Frameworks;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {
@@ -78,7 +66,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "/some/rooted/path",
-                CommandArguments = new [] { "arg with space"}
+                CommandArguments = new[] { "arg with space" }
             };
 
             var result = rootedCommandResolver.Resolve(commandResolverArguments);

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAScriptCommandResolver.cs

@@ -1,21 +1,10 @@
 // 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.Collections.Generic;
-using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
-using System.Text;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
-using NuGet.Frameworks;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {
@@ -33,7 +22,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             resolvers.Select(r => r.GetType())
                 .Should()
                 .ContainInOrder(
-                    new []{
+                    new[]{
                         typeof(RootedCommandResolver),
                         typeof(MuxerCommandResolver),
                         typeof(ProjectPathCommandResolver),

test/Microsoft.DotNet.Cli.Utils.Tests/GivenAnAppBaseCommandResolver.cs

@@ -2,20 +2,11 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Linq;
-using Xunit;
-using Moq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
-using System.Threading;
 using FluentAssertions;
-using NuGet.Frameworks;
+using Microsoft.DotNet.InternalAbstractions;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
 
 namespace Microsoft.DotNet.Cli.Utils.Tests
 {
@@ -107,7 +98,7 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
             var commandResolverArguments = new CommandResolverArguments()
             {
                 CommandName = "appbasetestcommand1",
-                CommandArguments = new [] { "arg with space"}
+                CommandArguments = new[] { "arg with space" }
             };
 
             var result = appBaseCommandResolver.Resolve(commandResolverArguments);
@@ -163,12 +154,12 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
 
         public void It_wraps_command_with_CMD_EXE_when_command_has_CMD_Extension_and_using_WindowsExePreferredCommandSpecFactory()
         {
-            var environment = new EnvironmentProvider(new [] {".cmd"});
+            var environment = new EnvironmentProvider(new[] { ".cmd" });
             var platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();
 
             var pathCommandResolver = new PathCommandResolver(environment, platformCommandSpecFactory);
 
-            var testCommandPath = 
+            var testCommandPath =
                 CommandResolverTestUtils.CreateNonRunnableTestCommand(AppContext.BaseDirectory, "cmdWrapCommand", ".cmd");
 
             var commandResolverArguments = new CommandResolverArguments()
@@ -193,9 +184,9 @@ namespace Microsoft.DotNet.Cli.Utils.Tests
         {
             environment = environment ?? new EnvironmentProvider();
 
-            IPlatformCommandSpecFactory platformCommandSpecFactory  = new GenericPlatformCommandSpecFactory();
+            IPlatformCommandSpecFactory platformCommandSpecFactory = new GenericPlatformCommandSpecFactory();
 
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform == Platform.Windows
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows
                 && !forceGeneric)
             {
                 platformCommandSpecFactory = new WindowsExePreferredCommandSpecFactory();

test/Microsoft.DotNet.Cli.Utils.Tests/StreamForwarderTests.cs

@@ -4,20 +4,16 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
-using System.Text;
-using Xunit;
 using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
+using Xunit;
-using System.Threading;
 
 namespace StreamForwarderTests
 {
     public class StreamForwarderTests : TestBase
     {
-        private static readonly string s_rid = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+        private static readonly string s_rid = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
         private static readonly string s_testProjectRoot = Path.Combine(AppContext.BaseDirectory, "TestAssets", "TestProjects");
 
         private TempDirectory _root;
@@ -57,7 +53,7 @@ namespace StreamForwarderTests
         [InlineData("123")]
         [InlineData("123\n")]
         public void TestNoForwardingNoCapture(string inputStr)
-        {   
+        {
             TestCapturingAndForwardingHelper(ForwardOptions.None, inputStr, null, new string[0]);
         }
 
@@ -65,11 +61,11 @@ namespace StreamForwarderTests
         [MemberData("ForwardingTheoryVariations")]
         public void TestForwardingOnly(string inputStr, string[] expectedWrites)
         {
-            for(int i = 0; i < expectedWrites.Length; ++i)
+            for (int i = 0; i < expectedWrites.Length; ++i)
             {
                 expectedWrites[i] += Environment.NewLine;
             }
-            
+
             TestCapturingAndForwardingHelper(ForwardOptions.WriteLine, inputStr, null, expectedWrites);
         }
 
@@ -77,13 +73,13 @@ namespace StreamForwarderTests
         [MemberData("ForwardingTheoryVariations")]
         public void TestCaptureOnly(string inputStr, string[] expectedWrites)
         {
-            for(int i = 0; i < expectedWrites.Length; ++i)
+            for (int i = 0; i < expectedWrites.Length; ++i)
             {
                 expectedWrites[i] += Environment.NewLine;
             }
 
             var expectedCaptured = string.Join("", expectedWrites);
-            
+
             TestCapturingAndForwardingHelper(ForwardOptions.Capture, inputStr, expectedCaptured, new string[0]);
         }
 
@@ -91,7 +87,7 @@ namespace StreamForwarderTests
         [MemberData("ForwardingTheoryVariations")]
         public void TestCaptureAndForwardingTogether(string inputStr, string[] expectedWrites)
         {
-            for(int i = 0; i < expectedWrites.Length; ++i)
+            for (int i = 0; i < expectedWrites.Length; ++i)
             {
                 expectedWrites[i] += Environment.NewLine;
             }

test/Microsoft.DotNet.Tools.Tests.Utilities/Commands/PublishCommand.cs

@@ -1,13 +1,13 @@
 // 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 Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
+using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
+using Microsoft.DotNet.ProjectModel;
 
 namespace Microsoft.DotNet.Tools.Test.Utilities
 {
@@ -69,10 +69,10 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
             string config = string.IsNullOrEmpty(_config) ? "Debug" : _config;
             string framework = string.IsNullOrEmpty(_framework) ?
                 _project.GetTargetFrameworks().First().FrameworkName.GetShortFolderName() : _framework;
-            
+
             if (!portable)
             {
-                var runtime = string.IsNullOrEmpty(_runtime) ? PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier() : _runtime;
+                var runtime = string.IsNullOrEmpty(_runtime) ? RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier() : _runtime;
                 return Path.Combine(config, framework, runtime, PublishSubfolderName);
             }
             else
@@ -120,7 +120,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
         private string RuntimeOption => string.IsNullOrEmpty(_runtime) ? "" : $"-r {_runtime}";
         private string OutputOption => string.IsNullOrEmpty(_output) ? "" : $"-o \"{_output}\"";
         private string ConfigOption => string.IsNullOrEmpty(_config) ? "" : $"-c {_output}";
-        private string NoBuildFlag => _noBuild ? "--no-build" :"";
+        private string NoBuildFlag => _noBuild ? "--no-build" : "";
         private string BuildBasePathOption => string.IsNullOrEmpty(_buidBasePathDirectory) ? "" : $"-b {_buidBasePathDirectory}";
     }
 }

test/Microsoft.DotNet.Tools.Tests.Utilities/WindowsOnlyFactAttribute.cs

@@ -1,7 +1,7 @@
 // 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 Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.InternalAbstractions;
 using Xunit;
 
 namespace Microsoft.DotNet.Tools.Test.Utilities
@@ -10,7 +10,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
     {
         public WindowsOnlyFactAttribute()
         {
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform != Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
                 this.Skip = "This test requires windows to run";
             }
@@ -21,7 +21,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
     {
         public WindowsOnlyTheoryAttribute()
         {
-            if (PlatformServices.Default.Runtime.OperatingSystemPlatform != Platform.Windows)
+            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
                 this.Skip = "This test requires windows to run";
             }

test/Microsoft.Extensions.DependencyModel.Tests/PackageResolverTest.cs

@@ -5,11 +5,9 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using FluentAssertions;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.Extensions.DependencyModel.Resolution;
-using Microsoft.Extensions.PlatformAbstractions;
-using Moq;
 using Xunit;
-
 using F = Microsoft.Extensions.DependencyModel.Tests.TestLibraryFactory;
 
 namespace Microsoft.Extensions.DependencyModel.Tests
@@ -21,13 +19,11 @@ namespace Microsoft.Extensions.DependencyModel.Tests
         [Fact]
         public void SholdUseEnvironmentVariableToGetDefaultLocation()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("NUGET_PACKAGES", PackagesPath)
                 .Build();
 
-            var result = PackageCompilationAssemblyResolver.GetDefaultPackageDirectory(runtime.Object, environment);
+            var result = PackageCompilationAssemblyResolver.GetDefaultPackageDirectory(Platform.Unknown, environment);
             result.Should().Be(PackagesPath);
         }
 
@@ -35,28 +31,22 @@ namespace Microsoft.Extensions.DependencyModel.Tests
         [Fact]
         public void SholdUseNugetUnderUserProfileOnWindows()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Windows);
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("USERPROFILE", "User Profile")
                 .Build();
 
-            var result = PackageCompilationAssemblyResolver.GetDefaultPackageDirectory(runtime.Object, environment);
+            var result = PackageCompilationAssemblyResolver.GetDefaultPackageDirectory(Platform.Windows, environment);
             result.Should().Be(Path.Combine("User Profile", ".nuget", "packages"));
         }
 
         [Fact]
         public void SholdUseNugetUnderHomeOnNonWindows()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Linux);
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("HOME", "User Home")
                 .Build();
 
-            var result = PackageCompilationAssemblyResolver.GetDefaultPackageDirectory(runtime.Object, environment);
+            var result = PackageCompilationAssemblyResolver.GetDefaultPackageDirectory(Platform.Linux, environment);
             result.Should().Be(Path.Combine("User Home", ".nuget", "packages"));
         }
 

test/Microsoft.Extensions.DependencyModel.Tests/ReferenceAssemblyResolverTests.cs

@@ -5,11 +5,9 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using FluentAssertions;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.Extensions.DependencyModel.Resolution;
-using Microsoft.Extensions.PlatformAbstractions;
-using Moq;
 using Xunit;
-
 using F = Microsoft.Extensions.DependencyModel.Tests.TestLibraryFactory;
 
 
@@ -34,53 +32,41 @@ namespace Microsoft.Extensions.DependencyModel.Tests
         [Fact]
         public void UsesEnvironmentVariableForDefaultPath()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Windows);
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("DOTNET_REFERENCE_ASSEMBLIES_PATH", ReferencePath)
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(runtime.Object, FileSystemMockBuilder.Empty, environment);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Windows, environment);
             result.Should().Be(ReferencePath);
         }
 
         [Fact]
         public void LooksOnlyOnEnvironmentVariableOnNonWindows()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Linux, EnvironmentMockBuilder.Empty);
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Linux);
-
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(runtime.Object, FileSystemMockBuilder.Empty, EnvironmentMockBuilder.Empty);
             result.Should().BeNull();
         }
 
         [Fact]
         public void ReturnsProgramFiles86AsDefaultLocationOnWin64()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Windows);
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("ProgramFiles(x86)", "Program Files (x86)")
                 .AddVariable("ProgramFiles", "Program Files")
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(runtime.Object, FileSystemMockBuilder.Empty, environment);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Windows, environment);
             result.Should().Be(Path.Combine("Program Files (x86)", "Reference Assemblies", "Microsoft", "Framework"));
         }
 
         [Fact]
         public void ReturnsProgramFilesAsDefaultLocationOnWin32()
         {
-            var runtime = new Mock<IRuntimeEnvironment>();
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Windows);
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("ProgramFiles", "Program Files")
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(runtime.Object, FileSystemMockBuilder.Empty, environment);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Windows, environment);
             result.Should().Be(Path.Combine("Program Files", "Reference Assemblies", "Microsoft", "Framework"));
         }
 
@@ -92,14 +78,11 @@ namespace Microsoft.Extensions.DependencyModel.Tests
                 .AddFiles(net20Path, "some.dll")
                 .Build();
 
-            var runtime = new Mock<IRuntimeEnvironment>();
-            runtime.SetupGet(r => r.OperatingSystemPlatform).Returns(Platform.Windows);
-
             var environment = EnvironmentMockBuilder.Create()
                 .AddVariable("WINDIR", "Windows")
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetFallbackSearchPaths(fileSystem, runtime.Object, environment);
+            var result = ReferenceAssemblyPathResolver.GetFallbackSearchPaths(fileSystem, Platform.Windows, environment);
             result.Should().Contain(net20Path);
         }
 

test/Performance/HelloWorld.cs

@@ -3,13 +3,8 @@
 
 using System;
 using System.IO;
-using System.Linq;
-using System.Runtime.InteropServices;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
 using Microsoft.Xunit.Performance;
-using Xunit;
-using System.Diagnostics;
 
 namespace Microsoft.DotNet.Tests.Performance
 {

test/binding-redirects.Tests/BindingRedirectTests.cs

@@ -6,14 +6,10 @@ using System.Collections.Generic;
 using System.Configuration;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
 using System.Xml.Linq;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.DotNet.TestFramework;
-using Microsoft.Extensions.PlatformAbstractions;
-using Xunit;
 using FluentAssertions;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
 
 namespace Microsoft.DotNet.Tests
 {

test/binding-redirects.Tests/TestSetupFixture.cs

@@ -1,16 +1,10 @@
 // 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.Collections.Generic;
 using System.IO;
-using System.Linq;
+using Microsoft.DotNet.InternalAbstractions;
-using System.Runtime.InteropServices;
-using Microsoft.DotNet.Cli.Utils;
-using Microsoft.DotNet.Tools.Test.Utilities;
 using Microsoft.DotNet.TestFramework;
-using Microsoft.Extensions.PlatformAbstractions;
+using Microsoft.DotNet.Tools.Test.Utilities;
-using Xunit;
 
 namespace Microsoft.DotNet.Tests
 {
@@ -21,7 +15,7 @@ namespace Microsoft.DotNet.Tests
         private const string AppWithConfig = "AppWithRedirectsAndConfig";
         private const string AppWithoutConfig = "AppWithRedirectsNoConfig";
 
-        private string _Runtime = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+        private string _Runtime = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
         private string _desktopProjectsRoot = Path.Combine(RepoRoot, "TestAssets", "DesktopTestProjects");
         private string _buildRelativePath;
         private string _appWithConfigProjectRoot;

test/dotnet-build.Tests/BuildOutputTests.cs

@@ -6,9 +6,9 @@ using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 using FluentAssertions;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
 using Newtonsoft.Json.Linq;
 using NuGet.Frameworks;
 using Xunit;
@@ -69,7 +69,7 @@ namespace Microsoft.DotNet.Tools.Builder.Tests
             var contexts = ProjectContext.CreateContextForEachFramework(
                 _testAppDirDirInfo.FullName,
                 null,
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers());
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers());
             _runtime = contexts.FirstOrDefault(c => !string.IsNullOrEmpty(c.RuntimeIdentifier))?.RuntimeIdentifier;
         }
 
@@ -177,9 +177,9 @@ namespace Microsoft.DotNet.Tools.Builder.Tests
         }
 
         [Theory]
-//        [InlineData("net20", false, true)]
+        //        [InlineData("net20", false, true)]
-//        [InlineData("net40", true, true)]
+        //        [InlineData("net40", true, true)]
-//        [InlineData("net461", true, true)]
+        //        [InlineData("net461", true, true)]
         [InlineData("netstandard1.5", true, false)]
         public void MultipleFrameworks_ShouldHaveValidTargetFrameworkAttribute(string frameworkName, bool shouldHaveTargetFrameworkAttribute, bool windowsOnly)
         {

test/dotnet-build.Tests/BuildStandAloneTests.cs

@@ -2,14 +2,14 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System.IO;
-using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.DotNet.ProjectModel;
-using Microsoft.Extensions.PlatformAbstractions;
-using Xunit;
 using System.Linq;
-using Microsoft.DotNet.TestFramework;
-using Newtonsoft.Json.Linq;
 using FluentAssertions;
+using Microsoft.DotNet.InternalAbstractions;
+using Microsoft.DotNet.ProjectModel;
+using Microsoft.DotNet.TestFramework;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Newtonsoft.Json.Linq;
+using Xunit;
 
 namespace Microsoft.DotNet.Tools.Builder.Tests
 {
@@ -72,7 +72,7 @@ namespace Microsoft.DotNet.Tools.Builder.Tests
             var contexts = ProjectContext.CreateContextForEachFramework(
                 projectPath,
                 null,
-                PlatformServices.Default.Runtime.GetAllCandidateRuntimeIdentifiers());
+                RuntimeEnvironmentRidExtensions.GetAllCandidateRuntimeIdentifiers());
 
             var runtime = contexts.FirstOrDefault(c => !string.IsNullOrEmpty(c.RuntimeIdentifier))?.RuntimeIdentifier;
 

test/dotnet-compile.UnitTests/GivenThatICareAboutScriptVariablesFromAManagedCompiler.cs

@@ -4,14 +4,13 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using FluentAssertions;
+using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.ProjectModel;
 using Moq;
 using NuGet.Frameworks;
 using Xunit;
-using Microsoft.DotNet.Cli.Utils;
-using FluentAssertions;
-using System.Linq;
-using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.DotNet.Tools.Compiler.Tests
 {
@@ -70,7 +69,7 @@ namespace Microsoft.DotNet.Tools.Compiler.Tests
         [Fact]
         public void It_passes_a_RuntimeOutputDir_variable_to_the_pre_compile_scripts_if_rid_is_set_in_the_ProjectContext()
         {
-            var rid = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+            var rid = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
             var fixture = ScriptVariablesFixture.GetFixtureWithRids(rid);
             fixture.PreCompileScriptVariables.Should().ContainKey("compile:RuntimeOutputDir");
             fixture.PreCompileScriptVariables["compile:RuntimeOutputDir"].Should().Be(fixture.RuntimeOutputDir);
@@ -129,7 +128,7 @@ namespace Microsoft.DotNet.Tools.Compiler.Tests
         [Fact]
         public void It_passes_a_RuntimeOutputDir_variable_to_the_post_compile_scripts_if_rid_is_set_in_the_ProjectContext()
         {
-            var rid = PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier();
+            var rid = RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier();
             var fixture = ScriptVariablesFixture.GetFixtureWithRids(rid);
             fixture.PostCompileScriptVariables.Should().ContainKey("compile:RuntimeOutputDir");
             fixture.PostCompileScriptVariables["compile:RuntimeOutputDir"].Should().Be(fixture.RuntimeOutputDir);

test/dotnet-publish.Tests/PublishDesktopTests.cs

@@ -1,14 +1,11 @@
-using System.Diagnostics;
+using System.IO;
-using System.IO;
-using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
 using FluentAssertions;
-using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.InternalAbstractions;
 using Microsoft.DotNet.TestFramework;
 using Microsoft.DotNet.Tools.Test.Utilities;
-using Microsoft.Extensions.PlatformAbstractions;
 using Xunit;
 
 namespace Microsoft.DotNet.Tools.Publish.Tests
@@ -28,7 +25,7 @@ namespace Microsoft.DotNet.Tools.Publish.Tests
         [InlineData("win7-x86", "the-win-x86-version.txt")]
         public async Task DesktopApp_WithDependencyOnNativePackage_ProducesExpectedOutput(string runtime, string expectedOutputName)
         {
-            if(string.IsNullOrEmpty(expectedOutputName))
+            if (string.IsNullOrEmpty(expectedOutputName))
             {
                 expectedOutputName = $"the-win-{RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant()}-version.txt";
             }
@@ -57,7 +54,7 @@ namespace Microsoft.DotNet.Tools.Publish.Tests
         [InlineData("KestrelDesktop", "http://localhost:20207", "win7-x86", "libuv.dll", false)]
         public async Task DesktopApp_WithKestrel_WorksWhenPublished(string project, string url, string runtime, string libuvName, bool forceRunnable)
         {
-            var runnable = forceRunnable || string.IsNullOrEmpty(runtime) || (PlatformServices.Default.Runtime.GetLegacyRestoreRuntimeIdentifier().Contains(runtime));
+            var runnable = forceRunnable || string.IsNullOrEmpty(runtime) || (RuntimeEnvironmentRidExtensions.GetLegacyRestoreRuntimeIdentifier().Contains(runtime));
 
             var testInstance = GetTestInstance()
                 .WithLockFiles();