Make final API review changes to file enumeration (#27318)

* Make final API review changes to file enumeration

Tweak stack array initialization to just zero the first element in matcher algorithm.

cc: @danmosemsft @terrajobst

* Don't null out the native name to track conversion

4 files changed, 34 insertions, 8 deletions

diff --git a/src/System.IO.FileSystem/tests/Enumeration/AttributeTests.netcoreapp.cs b/src/System.IO.FileSystem/tests/Enumeration/AttributeTests.netcoreapp.cs
index d35783713f..2ba62dfb42 100644
--- a/src/System.IO.FileSystem/tests/Enumeration/AttributeTests.netcoreapp.cs
+++ b/src/System.IO.FileSystem/tests/Enumeration/AttributeTests.netcoreapp.cs
@@ -2,6 +2,7 @@
 // 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.Collections.Generic;
 using System.IO.Enumeration;
 using Xunit;
 
@@ -111,5 +112,30 @@ namespace System.IO.Tests.Enumeration
                 Assert.False(enumerator.MoveNext());
             }
         }
+
+        [Fact]
+        public void IsHiddenAttribute()
+        {
+            DirectoryInfo testDirectory = Directory.CreateDirectory(GetTestFilePath());
+            FileInfo fileOne = new FileInfo(Path.Combine(testDirectory.FullName, GetTestFileName()));
+
+            // Put a period in front to make it hidden on Unix
+            FileInfo fileTwo = new FileInfo(Path.Combine(testDirectory.FullName, "." + GetTestFileName()));
+
+            fileOne.Create().Dispose();
+            fileTwo.Create().Dispose();
+            if (PlatformDetection.IsWindows)
+                fileTwo.Attributes = fileTwo.Attributes | FileAttributes.Hidden;
+
+            IEnumerable<string> enumerable = new FileSystemEnumerable<string>(
+                testDirectory.FullName,
+                (ref FileSystemEntry entry) => entry.ToFullPath(),
+                new EnumerationOptions() { AttributesToSkip = 0 })
+            {
+                ShouldIncludePredicate = (ref FileSystemEntry entry) => entry.IsHidden
+            };
+
+            Assert.Equal(new string[] { fileTwo.FullName }, enumerable);
+        }
     }
 }
diff --git a/src/System.IO.FileSystem/tests/Enumeration/PatternTransformTests.netcoreapp.cs b/src/System.IO.FileSystem/tests/Enumeration/PatternTransformTests.netcoreapp.cs
index d9e8b5330d..9cb33e5853 100644
--- a/src/System.IO.FileSystem/tests/Enumeration/PatternTransformTests.netcoreapp.cs
+++ b/src/System.IO.FileSystem/tests/Enumeration/PatternTransformTests.netcoreapp.cs
@@ -32,7 +32,7 @@ namespace System.IO.Tests.Enumeration
             string[] results = GetFiles(testDirectory.FullName, pattern);
             FSAssert.EqualWhenOrdered(new string[] { fileOne.FullName, fileTwo.FullName }, results);
 
-            results = GetFiles(testDirectory.FullName, pattern, new EnumerationOptions { MatchType = MatchType.Dos });
+            results = GetFiles(testDirectory.FullName, pattern, new EnumerationOptions { MatchType = MatchType.Win32 });
             FSAssert.EqualWhenOrdered(new string[] { fileOne.FullName, fileTwo.FullName }, results);
         }
 
diff --git a/src/System.IO.FileSystem/tests/Enumeration/DosMatcherTests.netcoreapp.cs b/src/System.IO.FileSystem/tests/Enumeration/Win32MatcherTests.netcoreapp.cs
index 508f0f6bf9..bc1d529969 100644
--- a/src/System.IO.FileSystem/tests/Enumeration/DosMatcherTests.netcoreapp.cs
+++ b/src/System.IO.FileSystem/tests/Enumeration/Win32MatcherTests.netcoreapp.cs
@@ -7,15 +7,15 @@ using Xunit;
 
 namespace System.IO.Tests
 {
-    public class DosMatcherTests
+    public class Win32MatcherTests
     {
-        [Theory, MemberData(nameof(DosMatchData)), MemberData(nameof(EscapedDosMatchData))]
-        public static void DosMatch(string expression, string name, bool ignoreCase, bool expected)
+        [Theory, MemberData(nameof(Win32MatchData)), MemberData(nameof(EscapedWin32MatchData))]
+        public static void Win32Match(string expression, string name, bool ignoreCase, bool expected)
         {
-            Assert.Equal(expected, FileSystemName.MatchesDosExpression(expression, name.AsSpan(), ignoreCase));
+            Assert.Equal(expected, FileSystemName.MatchesWin32Expression(expression, name.AsSpan(), ignoreCase));
         }
 
-        public static TheoryData<string, string, bool, bool> EscapedDosMatchData => new TheoryData<string, string, bool, bool>
+        public static TheoryData<string, string, bool, bool> EscapedWin32MatchData => new TheoryData<string, string, bool, bool>
         {
             // Trailing escape matches as it is considered "invisible"
             { "\\", "\\", false, true },
@@ -43,7 +43,7 @@ namespace System.IO.Tests
             { "\\\"", "\"", true, true },
         };
 
-        public static TheoryData<string, string, bool, bool> DosMatchData => new TheoryData<string, string, bool, bool>
+        public static TheoryData<string, string, bool, bool> Win32MatchData => new TheoryData<string, string, bool, bool>
         {
             { null, "", false, false },
             { null, "", true, false },
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 672d5642dc..5ff308577c 100644
--- a/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
+++ b/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\DosMatcherTests.netcoreapp.cs" />
+    <Compile Include="Enumeration\Win32MatcherTests.netcoreapp.cs" />
     <Compile Include="Enumeration\MatchCasingTests.netcoreapp.cs" />
     <Compile Include="Enumeration\TrimmedPaths.netcoreapp.cs" />
     <Compile Include="Enumeration\ErrorHandlingTests.netcoreapp.cs" />