Expect UnauthorizedAccessException in tvOS if extracting fifo from tar without elevation (#71175)

* Add ConditionalFact to 'unelevated' tests to ensure they are not executed in elevated mode.

* Fix test that was incorrectly executed async

src/libraries/System.Formats.Tar/tests/TarFile/TarFile.ExtractToDirectory.File.Tests.Unix.cs

@@ -9,7 +9,7 @@ namespace System.Formats.Tar.Tests
 {
     public partial class TarFile_ExtractToDirectory_File_Tests : TarTestsBase
     {
-        [Fact]
+        [ConditionalFact(nameof(IsUnixButNotSuperUser))]
         public void Extract_SpecialFiles_Unix_Unelevated_ThrowsUnauthorizedAccess()
         {
             string originalFileName = GetTarFilePath(CompressionMethod.Uncompressed, TestTarFormat.ustar, "specialfiles");

src/libraries/System.Formats.Tar/tests/TarFile/TarFile.ExtractToDirectoryAsync.File.Tests.Unix.cs

@@ -10,7 +10,7 @@ namespace System.Formats.Tar.Tests
 {
     public partial class TarFile_ExtractToDirectoryAsync_File_Tests : TarTestsBase
     {
-        [Fact]
+        [ConditionalFact(nameof(IsUnixButNotSuperUser))]
         public async Task Extract_SpecialFiles_Unix_Unelevated_ThrowsUnauthorizedAccess_Async()
         {
             using (TempDirectory root = new TempDirectory())

src/libraries/System.Formats.Tar/tests/TarReader/TarReader.TarEntry.ExtractToFile.Tests.Unix.cs

@@ -10,36 +10,35 @@ namespace System.Formats.Tar.Tests
     public partial class TarReader_TarEntry_ExtractToFile_Tests : TarTestsBase
     {
         [PlatformSpecific(TestPlatforms.AnyUnix & ~TestPlatforms.tvOS)] // https://github.com/dotnet/runtime/issues/68360
-        [Fact]
-        public async Task SpecialFile_Unelevated_Throws_Async()
+        [ConditionalFact(nameof(IsUnixButNotSuperUser))]
+        public void SpecialFile_Unelevated_Throws()
         {
             using TempDirectory root = new TempDirectory();
             using MemoryStream ms = GetTarMemoryStream(CompressionMethod.Uncompressed, TestTarFormat.ustar, "specialfiles");
 
-            TarReader reader = new TarReader(ms);
-            await using (reader)
+            using (TarReader reader = new TarReader(ms))
             {
                 string path = Path.Join(root.Path, "output");
 
                 // Block device requires elevation for writing
-                PosixTarEntry blockDevice = await reader.GetNextEntryAsync() as PosixTarEntry;
+                PosixTarEntry blockDevice = reader.GetNextEntry() as PosixTarEntry;
                 Assert.NotNull(blockDevice);
-                await Assert.ThrowsAsync<UnauthorizedAccessException>(() => blockDevice.ExtractToFileAsync(path, overwrite: false));
+                Assert.Throws<UnauthorizedAccessException>(() => blockDevice.ExtractToFile(path, overwrite: false));
                 Assert.False(File.Exists(path));
 
                 // Character device requires elevation for writing
-                PosixTarEntry characterDevice = await reader.GetNextEntryAsync() as PosixTarEntry;
+                PosixTarEntry characterDevice = reader.GetNextEntry() as PosixTarEntry;
                 Assert.NotNull(characterDevice);
-                await Assert.ThrowsAsync<UnauthorizedAccessException>(() => characterDevice.ExtractToFileAsync(path, overwrite: false));
+                Assert.Throws<UnauthorizedAccessException>(() => characterDevice.ExtractToFile(path, overwrite: false));
                 Assert.False(File.Exists(path));
 
                 // Fifo does not require elevation, should succeed
-                PosixTarEntry fifo = await reader.GetNextEntryAsync() as PosixTarEntry;
+                PosixTarEntry fifo = reader.GetNextEntry() as PosixTarEntry;
                 Assert.NotNull(fifo);
-                await fifo.ExtractToFileAsync(path, overwrite: false);
+                fifo.ExtractToFile(path, overwrite: false);
                 Assert.True(File.Exists(path));
 
-                Assert.Null(await reader.GetNextEntryAsync());
+                Assert.Null(reader.GetNextEntry());
             }
         }
     }

src/libraries/System.Formats.Tar/tests/TarReader/TarReader.TarEntry.ExtractToFileAsync.Tests.Unix.cs

@@ -10,7 +10,7 @@ namespace System.Formats.Tar.Tests
     public partial class TarReader_TarEntry_ExtractToFileAsync_Tests : TarTestsBase
     {
         [PlatformSpecific(TestPlatforms.AnyUnix & ~TestPlatforms.tvOS)] // https://github.com/dotnet/runtime/issues/68360
-        [Fact]
+        [ConditionalFact(nameof(IsUnixButNotSuperUser))]
         public async Task SpecialFile_Unelevated_Throws_Async()
         {
             using (TempDirectory root = new TempDirectory())

src/libraries/System.Formats.Tar/tests/TarTestsBase.cs

@@ -101,6 +101,8 @@ public enum TestTarFormat
         }
         protected static bool IsRemoteExecutorSupportedAndOnUnixAndSuperUser => RemoteExecutor.IsSupported && PlatformDetection.IsUnixAndSuperUser;
 
+        protected static bool IsUnixButNotSuperUser => !PlatformDetection.IsWindows && !PlatformDetection.IsSuperUser;
+
         protected static string GetTestCaseUnarchivedFolderPath(string testCaseName) =>
             Path.Join(Directory.GetCurrentDirectory(), "unarchived", testCaseName);