Keeping the old behavior with trailing separator

Reverted the changes to PhysicalFilesWatcher
and added back the trailing separator behavior
as per code review suggestion

Fix #62606

src/libraries/Microsoft.Extensions.FileProviders.Physical/src/PhysicalFilesWatcher.cs

@@ -340,15 +340,6 @@ private void OnFileSystemEntryChange(string fullPath)
         {
             try
             {
-                // this can happen when the fullPath matches the root directory path
-                // but the root path is always created with a trailing slash
-                // this was masked by a side effect (bug) in RenamedEventArgs that was appending the trailing slash to fullPath value
-                // that behavior was changed with the fix for https://github.com/dotnet/runtime/issues/62606
-                if (fullPath.Length < _root.Length)
-                {
-                    return;
-                }
-
                 var fileSystemInfo = new FileInfo(fullPath);
                 if (FileSystemInfoHelper.IsExcluded(fileSystemInfo, _filters))
                 {

src/libraries/System.IO.FileSystem.Watcher/src/System.IO.FileSystem.Watcher.csproj

@@ -25,10 +25,12 @@
     <Compile Include="System\IO\WaitForChangedResult.cs" />
     <Compile Include="$(CommonPath)System\IO\PathInternal.CaseSensitivity.cs"
              Link="Common\System\IO\PathInternal.CaseSensitivity.cs" />
-  </ItemGroup>
-  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
+    <Compile Include="$(CommonPath)System\IO\PathInternal.cs"
+            Link="Common\System\IO\PathInternal.cs" />
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs"
              Link="Common\System\Text\ValueStringBuilder.cs" />
+  </ItemGroup>
+  <ItemGroup Condition=" '$(TargetsWindows)' == 'true'">
     <Compile Include="$(CommonPath)System\IO\PathInternal.Windows.cs"
              Link="Common\System\IO\PathInternal.Windows.cs" />
     <Compile Include="$(CommonPath)Interop\Windows\Interop.Libraries.cs"

src/libraries/System.IO.FileSystem.Watcher/src/System/IO/FileSystemEventArgs.cs

@@ -20,6 +20,11 @@ public FileSystemEventArgs(WatcherChangeTypes changeType, string directory, stri
             _changeType = changeType;
             _name = name;
             _fullPath = Path.Join(Path.GetFullPath(directory), name);
+
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                _fullPath = PathInternal.EnsureTrailingSeparator(_fullPath);
+            }
         }
 
         /// <devdoc>

src/libraries/System.IO.FileSystem.Watcher/src/System/IO/RenamedEventArgs.cs

@@ -19,6 +19,11 @@ public RenamedEventArgs(WatcherChangeTypes changeType, string directory, string?
         {
             _oldName = oldName;
             _oldFullPath = Path.Join(Path.GetFullPath(directory), oldName);
+
+            if (string.IsNullOrWhiteSpace(oldName))
+            {
+                _oldFullPath = PathInternal.EnsureTrailingSeparator(_oldFullPath);
+            }
         }
 
         /// <devdoc>

src/libraries/System.IO.FileSystem.Watcher/tests/Args.FileSystemEventArgs.cs

@@ -81,10 +81,12 @@ public static void FileSystemEventArgs_ctor_RelativePathFromCurrentDirectoryInGi
         [Theory]
         [InlineData("bar", "")]
         [InlineData("bar", null)]
-        public static void FileSystemEventArgs_ctor_When_EmptyFileName_Then_FullPathReturnsTheDirectoryFullPath(string directory, string name)
+        public static void FileSystemEventArgs_ctor_When_EmptyFileName_Then_FullPathReturnsTheDirectoryFullPath_WithTrailingSeparator(string directory, string name)
         {
             FileSystemEventArgs args = new FileSystemEventArgs(WatcherChangeTypes.All, directory, name);
 
+            directory = PathInternal.EnsureTrailingSeparator(directory);
+
             Assert.Equal(PathInternal.EnsureTrailingSeparator(Directory.GetCurrentDirectory()) + directory, args.FullPath);
         }
 

src/libraries/System.IO.FileSystem.Watcher/tests/Args.RenamedEventArgs.cs

@@ -31,8 +31,6 @@ public static void RenamedEventArgs_ctor_OldFullPath_DirectoryIsAnAbsolutePath_W
             RenamedEventArgs args = new RenamedEventArgs(WatcherChangeTypes.All, directory, name, oldName);
 
             Assert.Equal(expectedOldFullPath, args.OldFullPath);
-            Assert.Equal(name, args.Name);
-            Assert.Equal(oldName, args.OldName);
         }
 
         [Theory]
@@ -86,10 +84,12 @@ public static void RenamedEventArgs_ctor_OldFullPath_DirectoryIsRelativePathFrom
         [InlineData( "bar", "", "")]
         [InlineData( "bar", null, null)]
         [InlineData( "bar", "foo.txt", null)]
-        public static void RenamedEventArgs_ctor_When_EmptyOldFileName_Then_OldFullPathReturnsTheDirectoryFullPath(string directory, string name, string oldName)
+        public static void RenamedEventArgs_ctor_When_EmptyOldFileName_Then_OldFullPathReturnsTheDirectoryFullPath_WithTrailingSeparator(string directory, string name, string oldName)
         {
             RenamedEventArgs args = new RenamedEventArgs(WatcherChangeTypes.All, directory, name, oldName);
 
+            directory = PathInternal.EnsureTrailingSeparator(directory);
+
             Assert.Equal(PathInternal.EnsureTrailingSeparator(Directory.GetCurrentDirectory()) + directory, args.OldFullPath);
         }