From 7acfee357058469e1133bcb09d3142fda947b1e4 Mon Sep 17 00:00:00 2001
From: Eric Erhardt <eric.erhardt@microsoft.com>
Date: Fri, 1 Mar 2019 11:46:42 -0600
Subject: [PATCH] Remove DependencyModel's dependency on PlatformAbstractions
 (dotnet/core-setup#5218)

* Remove DependencyModel's dependency on PlatformAbstractions

Working towards dotnet/core-setup#5213


Commit migrated from https://github.com/dotnet/core-setup/commit/e43465a759f9d887aa8d605faeaf4508c581f2db
---
 .../ApplicationEnvironment.cs                 | 25 +++++++++
 .../EnvironmentWrapper.cs                     |  6 ++
 .../IEnvironment.cs                           |  1 +
 ...icrosoft.Extensions.DependencyModel.csproj | 14 ++---
 .../AppBaseCompilationAssemblyResolver.cs     |  1 -
 .../DotNetReferenceAssembliesPathResolver.cs  |  8 +--
 .../PackageCompilationAssemblyResolver.cs     | 55 +++++++++----------
 .../ReferenceAssemblyPathResolver.cs          | 13 ++---
 .../EnvironmentMockBuilder.cs                 | 18 +++++-
 .../PackageResolverTest.cs                    | 11 ++--
 .../ReferenceAssemblyResolverTests.cs         | 14 +++--
 11 files changed, 103 insertions(+), 63 deletions(-)
 create mode 100644 src/installer/managed/Microsoft.Extensions.DependencyModel/ApplicationEnvironment.cs

diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/ApplicationEnvironment.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/ApplicationEnvironment.cs
new file mode 100644
index 0000000000000..2a7e528893a3c
--- /dev/null
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/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.Extensions.DependencyModel
+{
+    internal static class ApplicationEnvironment
+    {
+        public static string ApplicationBasePath { get; } = GetApplicationBasePath();
+
+        private static string GetApplicationBasePath()
+        {
+            string basePath =
+#if NET451
+                (string)AppDomain.CurrentDomain.GetData("APP_CONTEXT_BASE_DIRECTORY") ??
+                AppDomain.CurrentDomain.BaseDirectory;
+#else
+                AppContext.BaseDirectory;
+#endif
+            return Path.GetFullPath(basePath);
+        }
+    }
+}
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/EnvironmentWrapper.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/EnvironmentWrapper.cs
index c8254b1a6c305..8b657e9d8110d 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/EnvironmentWrapper.cs
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/EnvironmentWrapper.cs
@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
+using System.Runtime.InteropServices;
 
 namespace Microsoft.Extensions.DependencyModel
 {
@@ -13,5 +14,10 @@ public string GetEnvironmentVariable(string name)
         {
             return Environment.GetEnvironmentVariable(name);
         }
+
+        public bool IsWindows()
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+        }
     }
 }
\ No newline at end of file
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/IEnvironment.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/IEnvironment.cs
index c468709cc51ef..d22e00a18ea92 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/IEnvironment.cs
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/IEnvironment.cs
@@ -6,5 +6,6 @@ namespace Microsoft.Extensions.DependencyModel
     internal interface IEnvironment
     {
         string GetEnvironmentVariable(string name);
+        bool IsWindows();
     }
 }
\ No newline at end of file
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/Microsoft.Extensions.DependencyModel.csproj b/src/installer/managed/Microsoft.Extensions.DependencyModel/Microsoft.Extensions.DependencyModel.csproj
index 2cddc4e727f2f..a23f5324de677 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/Microsoft.Extensions.DependencyModel.csproj
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/Microsoft.Extensions.DependencyModel.csproj
@@ -8,6 +8,10 @@
     <LangVersion>7.3</LangVersion>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="..\Microsoft.DotNet.PlatformAbstractions\HashCodeCombiner.cs" />
+  </ItemGroup>
+  
   <Choose>
     <!--
     Since we added a target for netstandard2.0 so users aren't forced to download the 1.x dependencies,
@@ -39,6 +43,7 @@
     <Otherwise>
       <ItemGroup>
         <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
+        <PackageReference Include="System.Runtime.InteropServices.RuntimeInformation" Version="4.0.0" />
       </ItemGroup>
       <ItemGroup>
         <Compile Remove="ArrayBufferWriter.cs" />
@@ -50,16 +55,11 @@
     </Otherwise>
   </Choose>
 
-  <ItemGroup>
-    <ProjectReference Include="..\Microsoft.DotNet.PlatformAbstractions\Microsoft.DotNet.PlatformAbstractions.csproj" />
-  </ItemGroup>
-
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' Or '$(TargetFramework)' == 'netstandard1.6' ">
+    <PackageReference Include="System.AppContext" Version="4.1.0" />
     <PackageReference Include="System.Diagnostics.Debug" Version="4.0.11" />
     <PackageReference Include="System.Dynamic.Runtime" Version="4.0.11" />
-    <PackageReference Include="System.Linq" Version="4.1.0" />
-    <PackageReference Include="System.Diagnostics.Debug" Version="4.0.11" />
-    <PackageReference Include="System.Dynamic.Runtime" Version="4.0.11" />
+    <PackageReference Include="System.IO.FileSystem" Version="4.0.1" />
     <PackageReference Include="System.Linq" Version="4.1.0" />
   </ItemGroup>
 
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/AppBaseCompilationAssemblyResolver.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/AppBaseCompilationAssemblyResolver.cs
index 7cbafacbf28ed..e9e52c2adef5a 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/AppBaseCompilationAssemblyResolver.cs
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/AppBaseCompilationAssemblyResolver.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Microsoft.DotNet.PlatformAbstractions;
 
 #if !NETSTANDARD1_3
 
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/DotNetReferenceAssembliesPathResolver.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/DotNetReferenceAssembliesPathResolver.cs
index 98ee12a23ae3c..ebdae06237cee 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/DotNetReferenceAssembliesPathResolver.cs
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/DotNetReferenceAssembliesPathResolver.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.DotNet.PlatformAbstractions;
+using System.Runtime.InteropServices;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
 {
@@ -27,14 +27,12 @@ public static string Resolve()
 
         private static string GetDefaultDotNetReferenceAssembliesPath(IFileSystem fileSystem)
         {
-            var os = RuntimeEnvironment.OperatingSystemPlatform;
-
-            if (os == Platform.Windows)
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
                 return null;
             }
 
-            if (os == Platform.Darwin &&
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX) &&
                 fileSystem.Directory.Exists("/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/xbuild-frameworks"))
             {
                 return "/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/xbuild-frameworks";
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/PackageCompilationAssemblyResolver.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/PackageCompilationAssemblyResolver.cs
index 82976ae605ac9..7e3a9b50d5350 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/PackageCompilationAssemblyResolver.cs
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/PackageCompilationAssemblyResolver.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Microsoft.DotNet.PlatformAbstractions;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
 {
@@ -35,10 +34,7 @@ internal PackageCompilationAssemblyResolver(IFileSystem fileSystem, string[] nug
             _nugetPackageDirectories = nugetPackageDirectories;
         }
 
-        private static string[] GetDefaultProbeDirectories(IEnvironment environment) =>
-            GetDefaultProbeDirectories(RuntimeEnvironment.OperatingSystemPlatform, environment);
-
-        internal static string[] GetDefaultProbeDirectories(Platform osPlatform, IEnvironment environment)
+        internal static string[] GetDefaultProbeDirectories(IEnvironment environment)
         {
 #if !NETSTANDARD1_3            
 #if NETSTANDARD1_6
@@ -47,38 +43,37 @@ internal static string[] GetDefaultProbeDirectories(Platform osPlatform, IEnviro
             var probeDirectories = AppDomain.CurrentDomain.GetData("PROBING_DIRECTORIES");
 #endif
 
-           var listOfDirectories = probeDirectories as string;
+            var listOfDirectories = probeDirectories as string;
 
-           if (!string.IsNullOrEmpty(listOfDirectories))
-           {
-               return listOfDirectories.Split(new char [] { Path.PathSeparator }, StringSplitOptions.RemoveEmptyEntries );
-           }
+            if (!string.IsNullOrEmpty(listOfDirectories))
+            {
+                return listOfDirectories.Split(new char[] { Path.PathSeparator }, StringSplitOptions.RemoveEmptyEntries);
+            }
 #endif
 
-           var packageDirectory = environment.GetEnvironmentVariable("NUGET_PACKAGES");
+            var packageDirectory = environment.GetEnvironmentVariable("NUGET_PACKAGES");
 
-           if (!string.IsNullOrEmpty(packageDirectory))
-           {
-               return new string[] { packageDirectory };
-           }
-
-           string basePath;
-           if (osPlatform == Platform.Windows)
-           {
-               basePath = environment.GetEnvironmentVariable("USERPROFILE");
-           }
-           else
-           {
-               basePath = environment.GetEnvironmentVariable("HOME");
-           }
+            if (!string.IsNullOrEmpty(packageDirectory))
+            {
+                return new string[] { packageDirectory };
+            }
 
-           if (string.IsNullOrEmpty(basePath))
-           {
-               return new string[] { string.Empty };
-           }
+            string basePath;
+            if (environment.IsWindows())
+            {
+                basePath = environment.GetEnvironmentVariable("USERPROFILE");
+            }
+            else
+            {
+                basePath = environment.GetEnvironmentVariable("HOME");
+            }
 
-           return new string[] { Path.Combine(basePath, ".nuget", "packages") };
+            if (string.IsNullOrEmpty(basePath))
+            {
+                return new string[] { string.Empty };
+            }
 
+            return new string[] { Path.Combine(basePath, ".nuget", "packages") };
         }
 
         public bool TryResolveAssemblyPaths(CompilationLibrary library, List<string> assemblies)
diff --git a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/ReferenceAssemblyPathResolver.cs b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/ReferenceAssemblyPathResolver.cs
index bcbb088a48f77..c491ca9fc2ca2 100644
--- a/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/ReferenceAssemblyPathResolver.cs
+++ b/src/installer/managed/Microsoft.Extensions.DependencyModel/Resolution/ReferenceAssemblyPathResolver.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Microsoft.DotNet.PlatformAbstractions;
 
 namespace Microsoft.Extensions.DependencyModel.Resolution
 {
@@ -26,8 +25,8 @@ public ReferenceAssemblyPathResolver(string defaultReferenceAssembliesPath, stri
 
         internal ReferenceAssemblyPathResolver(IFileSystem fileSystem, IEnvironment environment)
             : this(fileSystem,
-                GetDefaultReferenceAssembliesPath(fileSystem, RuntimeEnvironment.OperatingSystemPlatform, environment),
-                GetFallbackSearchPaths(fileSystem, RuntimeEnvironment.OperatingSystemPlatform, environment))
+                GetDefaultReferenceAssembliesPath(fileSystem, environment),
+                GetFallbackSearchPaths(fileSystem, environment))
         {
         }
 
@@ -84,9 +83,9 @@ private bool TryResolveReferenceAssembly(string path, out string fullPath)
             return false;
         }
 
-        internal static string[] GetFallbackSearchPaths(IFileSystem fileSystem, Platform platform, IEnvironment environment)
+        internal static string[] GetFallbackSearchPaths(IFileSystem fileSystem, IEnvironment environment)
         {
-            if (platform != Platform.Windows)
+            if (!environment.IsWindows())
             {
                 return new string[0];
             }
@@ -100,7 +99,7 @@ internal static string[] GetFallbackSearchPaths(IFileSystem fileSystem, Platform
             return new[] { net20Dir };
         }
 
-        internal static string GetDefaultReferenceAssembliesPath(IFileSystem fileSystem, Platform platform, IEnvironment environment)
+        internal static string GetDefaultReferenceAssembliesPath(IFileSystem fileSystem, IEnvironment environment)
         {
             // Allow setting the reference assemblies path via an environment variable
             var referenceAssembliesPath = DotNetReferenceAssembliesPathResolver.Resolve(environment, fileSystem); 
@@ -109,7 +108,7 @@ internal static string GetDefaultReferenceAssembliesPath(IFileSystem fileSystem,
                 return referenceAssembliesPath;
             }
 
-            if (platform != Platform.Windows)
+            if (!environment.IsWindows())
             {
                 // There is no reference assemblies path outside of windows
                 // The environment variable can be used to specify one
diff --git a/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/EnvironmentMockBuilder.cs b/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/EnvironmentMockBuilder.cs
index 55e55065cb823..340ab91bc3292 100644
--- a/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/EnvironmentMockBuilder.cs
+++ b/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/EnvironmentMockBuilder.cs
@@ -9,6 +9,7 @@ namespace Microsoft.Extensions.DependencyModel.Tests
     public class EnvironmentMockBuilder
     {
         private Dictionary<string, string> _variables = new Dictionary<string, string>();
+        private bool _isWindows;
 
         internal static IEnvironment Empty { get; } = Create().Build();
 
@@ -23,18 +24,26 @@ public EnvironmentMockBuilder AddVariable(string name, string value)
             return this;
         }
 
+        public EnvironmentMockBuilder SetIsWindows(bool value)
+        {
+            _isWindows = value;
+            return this;
+        }
+
         internal IEnvironment Build()
         {
-            return new EnvironmentMock(_variables);
+            return new EnvironmentMock(_variables, _isWindows);
         }
 
         private class EnvironmentMock : IEnvironment
         {
             private Dictionary<string, string> _variables;
+            private bool _isWindows;
 
-            public EnvironmentMock(Dictionary<string, string> variables)
+            public EnvironmentMock(Dictionary<string, string> variables, bool isWindows)
             {
                 _variables = variables;
+                _isWindows = isWindows;
             }
 
             public string GetEnvironmentVariable(string name)
@@ -43,6 +52,11 @@ public string GetEnvironmentVariable(string name)
                 _variables.TryGetValue(name, out value);
                 return value;
             }
+
+            public bool IsWindows()
+            {
+                return _isWindows;
+            }
         }
     }
 }
diff --git a/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/PackageResolverTest.cs b/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/PackageResolverTest.cs
index fbf3e0eb4f828..e9e6b41c2a4cc 100644
--- a/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/PackageResolverTest.cs
+++ b/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/PackageResolverTest.cs
@@ -1,12 +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 FluentAssertions;
-using Microsoft.DotNet.PlatformAbstractions;
-using Microsoft.Extensions.DependencyModel;
 using Microsoft.Extensions.DependencyModel.Resolution;
 using Xunit;
 using F = Microsoft.Extensions.DependencyModel.Tests.TestLibraryFactory;
@@ -24,7 +21,7 @@ public void ShouldUseEnvironmentVariableToGetDefaultLocation()
                 .AddVariable("NUGET_PACKAGES", PackagesPath)
                 .Build();
 
-            var result = PackageCompilationAssemblyResolver.GetDefaultProbeDirectories(Platform.Unknown, environment);
+            var result = PackageCompilationAssemblyResolver.GetDefaultProbeDirectories(environment);
             // The host for .NET Core 2.0 always sets the PROBING_DIRECTORIES property on the AppContext. Because of that,
             // no additional package directories should be returned from this, even if they are set as environment variables.
             result.Should().NotContain(PackagesPath);
@@ -35,10 +32,11 @@ public void ShouldUseEnvironmentVariableToGetDefaultLocation()
         public void ShouldUseNugetUnderUserProfileOnWindows()
         {
             var environment = EnvironmentMockBuilder.Create()
+                .SetIsWindows(true)
                 .AddVariable("USERPROFILE", "User Profile")
                 .Build();
 
-            var result = PackageCompilationAssemblyResolver.GetDefaultProbeDirectories(Platform.Windows, environment);
+            var result = PackageCompilationAssemblyResolver.GetDefaultProbeDirectories(environment);
             // The host for .NET Core 2.0 always sets the PROBING_DIRECTORIES property on the AppContext. Because of that,
             // no additional package directories should be returned from this, even if they are set as environment variables.
             result.Should().NotContain(Path.Combine("User Profile", ".nuget", "packages"));
@@ -48,10 +46,11 @@ public void ShouldUseNugetUnderUserProfileOnWindows()
         public void ShouldUseNugetUnderHomeOnNonWindows()
         {
             var environment = EnvironmentMockBuilder.Create()
+                .SetIsWindows(false)
                 .AddVariable("HOME", "User Home")
                 .Build();
 
-            var result = PackageCompilationAssemblyResolver.GetDefaultProbeDirectories(Platform.Linux, environment);
+            var result = PackageCompilationAssemblyResolver.GetDefaultProbeDirectories(environment);
             // The host for .NET Core 2.0 always sets the PROBING_DIRECTORIES property on the AppContext. Because of that,
             // no additional package directories should be returned from this, even if they are set as environment variables.
             result.Should().NotContain(Path.Combine("User Home", ".nuget", "packages"));
diff --git a/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/ReferenceAssemblyResolverTests.cs b/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/ReferenceAssemblyResolverTests.cs
index 9b48ed2066e4d..a389665b99266 100644
--- a/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/ReferenceAssemblyResolverTests.cs
+++ b/src/installer/test/Microsoft.Extensions.DependencyModel.Tests/ReferenceAssemblyResolverTests.cs
@@ -34,17 +34,18 @@ public void SkipsNonReferenceAssembly()
         public void UsesEnvironmentVariableForDefaultPath()
         {
             var environment = EnvironmentMockBuilder.Create()
+                .SetIsWindows(true)
                 .AddVariable("DOTNET_REFERENCE_ASSEMBLIES_PATH", ReferencePath)
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Windows, environment);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, environment);
             result.Should().Be(ReferencePath);
         }
 
         [Fact]
         public void LooksOnlyOnEnvironmentVariableOnNonWindows()
         {
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Linux, EnvironmentMockBuilder.Empty);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, EnvironmentMockBuilder.Empty);
             result.Should().BeNull();
         }
 
@@ -52,11 +53,12 @@ public void LooksOnlyOnEnvironmentVariableOnNonWindows()
         public void ReturnsProgramFiles86AsDefaultLocationOnWin64()
         {
             var environment = EnvironmentMockBuilder.Create()
+                .SetIsWindows(true)
                 .AddVariable("ProgramFiles(x86)", "Program Files (x86)")
                 .AddVariable("ProgramFiles", "Program Files")
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Windows, environment);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, environment);
             result.Should().Be(Path.Combine("Program Files (x86)", "Reference Assemblies", "Microsoft", "Framework"));
         }
 
@@ -64,10 +66,11 @@ public void ReturnsProgramFiles86AsDefaultLocationOnWin64()
         public void ReturnsProgramFilesAsDefaultLocationOnWin32()
         {
             var environment = EnvironmentMockBuilder.Create()
+                .SetIsWindows(true)
                 .AddVariable("ProgramFiles", "Program Files")
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, Platform.Windows, environment);
+            var result = ReferenceAssemblyPathResolver.GetDefaultReferenceAssembliesPath(FileSystemMockBuilder.Empty, environment);
             result.Should().Be(Path.Combine("Program Files", "Reference Assemblies", "Microsoft", "Framework"));
         }
 
@@ -80,10 +83,11 @@ public void ReturnNet20PathAsFallbackOnWindows()
                 .Build();
 
             var environment = EnvironmentMockBuilder.Create()
+                .SetIsWindows(true)
                 .AddVariable("WINDIR", "Windows")
                 .Build();
 
-            var result = ReferenceAssemblyPathResolver.GetFallbackSearchPaths(fileSystem, Platform.Windows, environment);
+            var result = ReferenceAssemblyPathResolver.GetFallbackSearchPaths(fileSystem, environment);
             result.Should().Contain(net20Path);
         }