More FileSystem tests (#27955)

- Fix #27244 validation
- Add more enumerable tests

Fixes #27244

Author: JeremyKuhne

src/System.IO.FileSystem/tests/Enumeration/ErrorHandlingTests.netcoreapp.cs

@@ -16,27 +16,55 @@ public IgnoreErrors(string directory)
             { }
 
             public int ErrorCount { get; private set; }
+            public string DirectoryFinished { get; private set; }
 
             protected override string TransformEntry(ref FileSystemEntry entry)
-            {
-                throw new NotImplementedException();
-            }
+                => entry.FileName.ToString();
 
             protected override bool ContinueOnError(int error)
             {
                 ErrorCount++;
                 return true;
             }
+
+            protected override void OnDirectoryFinished(ReadOnlySpan<char> directory)
+                => DirectoryFinished = directory.ToString();
         }
 
         [Fact]
         public void OpenErrorDoesNotHappenAgainOnMoveNext()
         {
+            // What we're checking for here is that we don't try to enumerate when we
+            // couldn't even open the root directory (e.g. open the handle again, try
+            // to get data, etc.)
             using (IgnoreErrors ie = new IgnoreErrors(Path.GetRandomFileName()))
             {
                 Assert.Equal(1, ie.ErrorCount);
                 Assert.False(ie.MoveNext());
                 Assert.Equal(1, ie.ErrorCount);
+
+                // Since we didn't start, the directory shouldn't finish.
+                Assert.Null(ie.DirectoryFinished);
+            }
+        }
+
+        [Fact]
+        public void DeleteDirectoryAfterOpening()
+        {
+            // We shouldn't prevent the directory from being deleted, even though we've
+            // opened (and are holding) the handle. On Windows this means we've opened
+            // the handle with file share of delete.
+            DirectoryInfo info = Directory.CreateDirectory(GetTestFilePath());
+            using (IgnoreErrors ie = new IgnoreErrors(info.FullName))
+            {
+                Assert.Equal(0, ie.ErrorCount);
+                Directory.Delete(info.FullName);
+                Assert.False(ie.MoveNext());
+
+                // This doesn't cause an error as the directory is still valid until the
+                // the enumerator is closed (as we have an open handle)
+                Assert.Equal(0, ie.ErrorCount);
+                Assert.Equal(info.FullName, ie.DirectoryFinished);
             }
         }
     }

…meration/Win32MatcherTests.netcoreapp.cs …ration/FileSystemNameTests.netcoreapp.cssrc/System.IO.FileSystem/tests/Enumeration/Win32MatcherTests.netcoreapp.cs renamed to src/System.IO.FileSystem/tests/Enumeration/FileSystemNameTests.netcoreapp.cs src/System.IO.FileSystem/tests/Enumeration/Win32MatcherTests.netcoreapp.cs renamed to src/System.IO.FileSystem/tests/Enumeration/FileSystemNameTests.netcoreapp.cs

@@ -7,7 +7,7 @@
 
 namespace System.IO.Tests
 {
-    public class Win32MatcherTests
+    public class FileSystemNameTests
     {
         [Theory,
             MemberData(nameof(SimpleMatchData)),

src/System.IO.FileSystem/tests/Enumeration/RootTests.netcoreapp.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System.IO.Enumeration;
-using System.Linq;
 using Xunit;
 
 namespace System.IO.Tests.Enumeration
@@ -32,11 +31,11 @@ protected override bool ShouldRecurseIntoEntry(ref FileSystemEntry entry)
             }
         }
 
-        [ActiveIssue(27244)]
         [Fact]
         public void CanRecurseFromRoot()
         {
             string root = Path.GetPathRoot(Path.GetTempPath());
+
             using (var recursed = new DirectoryRecursed(root, new EnumerationOptions { AttributesToSkip = FileAttributes.System, RecurseSubdirectories = true }))
             {
                 while (recursed.MoveNext())
@@ -47,9 +46,10 @@ public void CanRecurseFromRoot()
                         return;
                     }
 
-                    // Should not get back a full path without a single separator (C:\foo.txt or /foo.txt)
-                    int count = recursed.Current.Count(c => c == Path.DirectorySeparatorChar);
-                    Assert.True(count <= 1, $"expected to find just one separator in '{recursed.Current}'");
+                    // Should start with the root and shouldn't have a separator after the root
+                    Assert.StartsWith(root, recursed.Current);
+                    Assert.True(recursed.Current.LastIndexOf(Path.DirectorySeparatorChar) < root.Length,
+                        $"should have no separators pasth the root '{root}' in in '{recursed.Current}'");
                 }
 
                 Assert.NotNull(recursed.LastDirectory);

src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj

@@ -56,7 +56,7 @@
     <Compile Include="Enumeration\ConstructionTests.netcoreapp.cs" />
     <Compile Include="Enumeration\SpecialDirectoryTests.netcoreapp.cs" />
     <Compile Include="Enumeration\SkipAttributeTests.netcoreapp.cs" />
-    <Compile Include="Enumeration\Win32MatcherTests.netcoreapp.cs" />
+    <Compile Include="Enumeration\FileSystemNameTests.netcoreapp.cs" />
     <Compile Include="Enumeration\MatchCasingTests.netcoreapp.cs" />
     <Compile Include="Enumeration\TrimmedPaths.netcoreapp.cs" />
     <Compile Include="Enumeration\ErrorHandlingTests.netcoreapp.cs" />