Fix some System.IO.PathTests on Desktop to support legacy path behavior (#19012)

* Fix System.IO.PathTests

3 files changed, 6 insertions, 101 deletions

diff --git a/src/System.IO.FileSystem/tests/PathFeatures.cs b/src/System.IO.FileSystem/tests/PathFeatures.cs
deleted file mode 100644
index 7062d9ee1a..0000000000
--- a/src/System.IO.FileSystem/tests/PathFeatures.cs
+++ /dev/null
@@ -1,99 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Reflection;
-using System.Runtime.InteropServices;
-
-namespace System.IO
-{
-    public static class PathFeatures
-    {
-        private enum State
-        {
-            Uninitialized,
-            True,
-            False
-        }
-
-        // Note that this class is using APIs that allow it to run on all platforms (including Core 5.0)
-        // That is why we have .GetTypeInfo(), don't use the Registry, etc...
-
-        private static State s_osEnabled;
-        private static State s_onCore;
-
-        /// <summary>
-        /// Returns true if you can use long paths, including long DOS style paths (e.g. over 260 without \\?\).
-        /// </summary>
-        public static bool AreAllLongPathsAvailable()
-        {
-            // We have support built-in for all platforms in Core
-            if (RunningOnCoreLib)
-                return true;
-
-            // Otherwise we're running on Windows, see if we've got the capability in .NET, and that the feature is enabled in the OS
-            return !AreLongPathsBlocked() && AreOsLongPathsEnabled();
-        }
-
-        public static bool IsUsingLegacyPathNormalization()
-        {
-            return HasLegacyIoBehavior("UseLegacyPathHandling");
-        }
-
-        /// <summary>
-        /// Returns true if > MAX_PATH (260) character paths are blocked.
-        /// Note that this doesn't reflect that you can actually use long paths without device syntax when on Windows.
-        /// Use AreAllLongPathsAvailable() to see that you can use long DOS style paths if on Windows.
-        /// </summary>
-        public static bool AreLongPathsBlocked()
-        {
-            return HasLegacyIoBehavior("BlockLongPaths");
-        }
-
-        private static bool HasLegacyIoBehavior(string propertyName)
-        {
-            // Core doesn't have legacy behaviors
-            if (RunningOnCoreLib)
-                return false;
-
-            Type t = typeof(object).GetTypeInfo().Assembly.GetType("System.AppContextSwitches");
-            var p = t.GetProperty(propertyName, BindingFlags.Static | BindingFlags.Public);
-
-            // If the switch actually exists use it, otherwise we predate the switch and are effectively on
-            return (bool)(p?.GetValue(null) ?? true);
-        }
-
-        private static bool RunningOnCoreLib
-        {
-            get
-            {
-                // Not particularly elegant
-                if (s_onCore == State.Uninitialized)
-                    s_onCore = typeof(object).GetTypeInfo().Assembly.GetName().Name == "System.Private.CoreLib" ? State.True : State.False;
-
-                return s_onCore == State.True;
-            }
-        }
-
-        private static bool AreOsLongPathsEnabled()
-        {
-            if (s_osEnabled == State.Uninitialized)
-            {
-                // No official way to check yet this is good enough for tests
-                try
-                {
-                    s_osEnabled = RtlAreLongPathsEnabled() ? State.True : State.False;
-                }
-                catch
-                {
-                    s_osEnabled = State.False;
-                }
-            }
-
-            return s_osEnabled == State.True;
-        }
-
-        [DllImport("ntdll", ExactSpelling = true)]
-        private static extern bool RtlAreLongPathsEnabled();
-    }
-}
diff --git a/src/System.IO.FileSystem/tests/Performance/System.IO.FileSystem.Performance.Tests.csproj b/src/System.IO.FileSystem/tests/Performance/System.IO.FileSystem.Performance.Tests.csproj
index 7df96f1f2d..2d9fd50a0f 100644
--- a/src/System.IO.FileSystem/tests/Performance/System.IO.FileSystem.Performance.Tests.csproj
+++ b/src/System.IO.FileSystem/tests/Performance/System.IO.FileSystem.Performance.Tests.csproj
@@ -16,7 +16,6 @@
     <Compile Include="..\PortedCommon\ReparsePointUtilities.cs" />
     <Compile Include="..\TestData.cs" />
     <Compile Include="..\FileSystemTest.cs" />
-    <Compile Include="..\PathFeatures.cs" />
     <Compile Include="Perf.Directory.cs" />
     <Compile Include="Perf.File.cs" />
     <Compile Include="Perf.FileInfo.cs" />
@@ -27,6 +26,9 @@
     <Compile Include="$(CommonTestPath)\System\IO\FileCleanupTestBase.cs">
       <Link>Common\System\IO\FileCleanupTestBase.cs</Link>
     </Compile>
+    <Compile Include="$(CommonTestPath)\System\IO\PathFeatures.cs">
+      <Link>Common\System\IO\PathFeatures.cs</Link>
+    </Compile>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(CommonPath)\..\perf\PerfRunner\PerfRunner.csproj">
diff --git a/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj b/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
index d265aaf3a2..109b8c4975 100644
--- a/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
+++ b/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
@@ -97,7 +97,6 @@
     <Compile Include="File\Move.cs" />
     <Compile Include="File\ReadWriteAllText.cs" />
     <Compile Include="File\ReadWriteAllLines.cs" />
-    <Compile Include="PathFeatures.cs" />
     <Compile Include="TestData.cs" />
     <Compile Include="UnseekableFileStream.cs" />
     <Compile Include="FSAssert.cs" />
@@ -160,6 +159,9 @@
     <Compile Include="$(CommonTestPath)\System\IO\TempFile.cs">
       <Link>Common\System\IO\TempFile.cs</Link>
     </Compile>
+    <Compile Include="$(CommonTestPath)\System\IO\PathFeatures.cs">
+      <Link>Common\System\IO\PathFeatures.cs</Link>
+    </Compile>
     <Compile Include="$(CommonTestPath)\System\PlatformDetection.cs">
       <Link>Common\System\PlatformDetection.cs</Link>
     </Compile>