fix: make MockFile.Exists handle empty string

src/System.IO.Abstractions.TestingHelpers/MockFile.cs

@@ -203,8 +203,24 @@ public override bool Exists(string path)
                 return false;
             }
 
-            var file = mockFileDataAccessor.GetFile(path);
-            return file != null && !file.IsDirectory;
+            if (path.Trim() == string.Empty)
+            {
+                return false;
+            }
+
+            try
+            {
+                mockFileDataAccessor.PathVerifier.IsLegalAbsoluteOrRelative(path, nameof(path));
+
+                var file = mockFileDataAccessor.GetFile(path);
+                return file != null && !file.IsDirectory;
+            }
+            catch (ArgumentException) { }
+            catch (NotSupportedException) { }
+            catch (IOException) { }
+            catch (UnauthorizedAccessException) { }
+
+            return false;
         }
 
         /// <inheritdoc />

tests/System.IO.Abstractions.TestingHelpers.Tests/MockFileExistsTests.cs

@@ -88,6 +88,32 @@ public void MockFile_Exists_ShouldReturnFalseForNullPath()
             Assert.IsFalse(result);
         }
 
+        [Test]
+        public void MockFile_Exists_ShouldReturnFalseForEmptyStringPath()
+        {
+            // Arrange
+            var fileSystem = new MockFileSystem();
+
+            // Act
+            var result = fileSystem.File.Exists(string.Empty);
+
+            // Assert
+            Assert.IsFalse(result);
+        }
+
+        [Test]
+        public void MockFile_Exists_ShouldReturnFalseForInvalidCharactersInPath()
+        {
+            // Arrange
+            var fileSystem = new MockFileSystem();
+
+            // Act
+            var result = fileSystem.File.Exists(@"C:""*/:<>?|abc");
+
+            // Assert
+            Assert.IsFalse(result);
+        }
+
         [Test]
         public void MockFile_Exists_ShouldReturnFalseForDirectories()
         {