Add tests for trailing spaces/periods and embedded whitespace scenarios

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

Author: Copilot

src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Copy.cs

@@ -496,6 +496,50 @@ public void WindowsCopyWithProblematicNames(string sourceFileName, string destFi
             Assert.True(File.Exists(sourcePath));
             Assert.True(File.Exists(destPath));
         }
+
+        [ConditionalTheory(nameof(UsingNewNormalization))]
+        [InlineData("trailing ", "destination")]
+        [InlineData("source", "trailing ")]
+        [InlineData("trailing.", "destination")]
+        [InlineData("source", "trailing.")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsCopyWithTrailingSpacePeriod_ViaExtendedSyntax(string sourceFileName, string destFileName)
+        {
+            // Files with trailing spaces/periods require \\?\ syntax on Windows
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string sourcePath = Path.Combine(testDir.FullName, sourceFileName);
+            string destPath = Path.Combine(testDir.FullName, destFileName);
+            
+            // Create source with extended syntax if needed
+            string sourceToCreate = sourceFileName.TrimEnd(' ', '.') != sourceFileName ? @"\\?\" + sourcePath : sourcePath;
+            File.Create(sourceToCreate).Dispose();
+            
+            // Copy with extended syntax if needed
+            string sourceToCopy = sourceFileName.TrimEnd(' ', '.') != sourceFileName ? @"\\?\" + sourcePath : sourcePath;
+            string destToCopy = destFileName.TrimEnd(' ', '.') != destFileName ? @"\\?\" + destPath : destPath;
+            
+            Copy(sourceToCopy, destToCopy);
+            
+            Assert.True(File.Exists(sourceToCopy));
+            Assert.True(File.Exists(destToCopy));
+        }
+
+        [Theory]
+        [InlineData("name with spaces", "dest with spaces")]
+        [InlineData("name.with.periods", "dest.with.periods")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsCopyEmbeddedSpacesPeriods(string sourceFileName, string destFileName)
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string sourcePath = Path.Combine(testDir.FullName, sourceFileName);
+            string destPath = Path.Combine(testDir.FullName, destFileName);
+
+            File.Create(sourcePath).Dispose();
+            Copy(sourcePath, destPath);
+
+            Assert.True(File.Exists(sourcePath));
+            Assert.True(File.Exists(destPath));
+        }
     }
 
     /// <summary>

src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Create.cs

@@ -431,6 +431,63 @@ public void WindowsLeadingDot(string fileName)
             }
         }
 
+        [ConditionalTheory(nameof(UsingNewNormalization))]
+        [InlineData("trailing ")]
+        [InlineData("trailing  ")]
+        [InlineData("trailing.")]
+        [InlineData("trailing..")]
+        [InlineData("trailing .")]
+        [InlineData("trailing. ")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsTrailingSpacePeriod_CreateViaExtendedSyntax(string fileName)
+        {
+            // Files with trailing spaces/periods require \\?\ syntax on Windows
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            string extendedPath = @"\\?\" + filePath;
+            
+            using (Create(extendedPath))
+            {
+                Assert.True(File.Exists(extendedPath));
+            }
+            
+            // Verify we can find it via enumeration
+            string[] files = Directory.GetFiles(testDir.FullName);
+            Assert.Contains(files, f => Path.GetFileName(f) == fileName);
+        }
+
+        [Theory]
+        [InlineData("name with spaces")]
+        [InlineData("name  with  multiple  spaces")]
+        [InlineData("name.with.periods")]
+        [InlineData("name with spaces.txt")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsEmbeddedSpacesPeriods(string fileName)
+        {
+            // Embedded spaces and periods should work fine
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            using (Create(filePath))
+            {
+                Assert.True(File.Exists(filePath));
+            }
+        }
+
+        [Theory]
+        [InlineData("name with spaces")]
+        [InlineData("name.with.periods")]
+        [InlineData("name\twith\ttabs")]
+        [PlatformSpecific(TestPlatforms.AnyUnix)]
+        public void UnixEmbeddedSpecialChars(string fileName)
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            using (Create(filePath))
+            {
+                Assert.True(File.Exists(filePath));
+            }
+        }
+
         #endregion
     }
 

src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Delete.cs

@@ -250,6 +250,40 @@ public void WindowsDeleteProblematicNames(string fileName)
             Assert.False(File.Exists(filePath));
         }
 
+        [ConditionalTheory(nameof(UsingNewNormalization))]
+        [InlineData("trailing ")]
+        [InlineData("trailing  ")]
+        [InlineData("trailing.")]
+        [InlineData("trailing..")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsDeleteTrailingSpacePeriod_ViaExtendedSyntax(string fileName)
+        {
+            // Files with trailing spaces/periods require \\?\ syntax on Windows
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            string extendedPath = @"\\?\" + filePath;
+            
+            File.Create(extendedPath).Dispose();
+            Assert.True(File.Exists(extendedPath));
+            
+            Delete(extendedPath);
+            Assert.False(File.Exists(extendedPath));
+        }
+
+        [Theory]
+        [InlineData("name with spaces")]
+        [InlineData("name.with.periods")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsDeleteEmbeddedSpacesPeriods(string fileName)
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            File.Create(filePath).Dispose();
+            Assert.True(File.Exists(filePath));
+            Delete(filePath);
+            Assert.False(File.Exists(filePath));
+        }
+
         #endregion
     }
 }

src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Exists.cs

@@ -273,6 +273,38 @@ public void WindowsExistsProblematicNames(string fileName)
             Assert.True(Exists(filePath));
         }
 
+        [ConditionalTheory(nameof(UsingNewNormalization))]
+        [InlineData("trailing ")]
+        [InlineData("trailing  ")]
+        [InlineData("trailing.")]
+        [InlineData("trailing..")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsExistsTrailingSpacePeriod_ViaExtendedSyntax(string fileName)
+        {
+            // Files with trailing spaces/periods require \\?\ syntax on Windows
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            string extendedPath = @"\\?\" + filePath;
+            
+            File.Create(extendedPath).Dispose();
+            Assert.True(Exists(extendedPath));
+            
+            // Without extended syntax, the trailing space/period is trimmed
+            Assert.False(Exists(filePath));
+        }
+
+        [Theory]
+        [InlineData("name with spaces")]
+        [InlineData("name.with.periods")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsExistsEmbeddedSpacesPeriods(string fileName)
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string filePath = Path.Combine(testDir.FullName, fileName);
+            File.Create(filePath).Dispose();
+            Assert.True(Exists(filePath));
+        }
+
         #endregion
     }
 

src/libraries/System.Runtime/tests/System.IO.FileSystem.Tests/File/Move.cs

@@ -467,5 +467,49 @@ public void WindowsMoveWithProblematicNames(string sourceFileName, string destFi
             Assert.False(File.Exists(srcPath));
             Assert.True(File.Exists(destPath));
         }
+
+        [ConditionalTheory(nameof(UsingNewNormalization))]
+        [InlineData("trailing ", "destination")]
+        [InlineData("source", "trailing ")]
+        [InlineData("trailing.", "destination")]
+        [InlineData("source", "trailing.")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsMoveWithTrailingSpacePeriod_ViaExtendedSyntax(string sourceFileName, string destFileName)
+        {
+            // Files with trailing spaces/periods require \\?\ syntax on Windows
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string srcPath = Path.Combine(testDir.FullName, sourceFileName);
+            string destPath = Path.Combine(testDir.FullName, destFileName);
+            
+            // Create source with extended syntax if needed
+            string sourceToCreate = sourceFileName.TrimEnd(' ', '.') != sourceFileName ? @"\\?\" + srcPath : srcPath;
+            File.Create(sourceToCreate).Dispose();
+            
+            // Move with extended syntax if needed
+            string sourceToMove = sourceFileName.TrimEnd(' ', '.') != sourceFileName ? @"\\?\" + srcPath : srcPath;
+            string destToMove = destFileName.TrimEnd(' ', '.') != destFileName ? @"\\?\" + destPath : destPath;
+            
+            Move(sourceToMove, destToMove);
+            
+            Assert.False(File.Exists(sourceToMove));
+            Assert.True(File.Exists(destToMove));
+        }
+
+        [Theory]
+        [InlineData("name with spaces", "dest with spaces")]
+        [InlineData("name.with.periods", "dest.with.periods")]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void WindowsMoveEmbeddedSpacesPeriods(string sourceFileName, string destFileName)
+        {
+            DirectoryInfo testDir = Directory.CreateDirectory(GetTestFilePath());
+            string srcPath = Path.Combine(testDir.FullName, sourceFileName);
+            string destPath = Path.Combine(testDir.FullName, destFileName);
+
+            File.Create(srcPath).Dispose();
+            Move(srcPath, destPath);
+
+            Assert.False(File.Exists(srcPath));
+            Assert.True(File.Exists(destPath));
+        }
     }
 }