Fix FSUtils.FileNameCorrection

Unit tests and fixes

ZeroLevel.UnitTests/FSUtilsTest.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using Xunit;
+using ZeroLevel.Services.FileSystem;
+
+namespace ZeroLevel.UnitTests
+{
+    public class FSUtilsTest
+    {
+        [Fact]
+        public void FileNameCorrectionTest()
+        {
+            // Arrange            
+            var validNames = new List<string> { "CON1", "a.cOn.a", "$PRN", "LPT10", "lpt10.txt", "COM11.ee" };
+            var invalidNames = new List<string> { "CON", "cOn", "PRN", "LPT4", "LPT4.", "LPT4.txt", "COM1.ee" };
+            var invalidRootNames = new List<string> { "$mft", "$mftmirr", "$logfile", "$volume", "$attrdef", "$bitmap", "$boot", "$badclus", "$secure", "$upcase", "$extend", "$quota", "$objid", "$reparse" };
+            // Act
+
+            // Assert
+            foreach (var validName in validNames)
+            {
+                Assert.Equal(validName, FSUtils.FileNameCorrection(validName));
+            }
+            foreach (var invalidName in invalidNames)
+            {
+                Assert.NotEqual(invalidName, FSUtils.FileNameCorrection(invalidName));
+            }
+            foreach (var invalidName in invalidRootNames)
+            {
+                Assert.NotEqual(invalidName, FSUtils.FileNameCorrection(invalidName, true));
+            }
+        }
+    }
+}

ZeroLevel/Services/FileSystem/FSUtils.cs

@@ -58,6 +58,8 @@ namespace ZeroLevel.Services.FileSystem
         private static string _invalid_filename_characters = new string(Path.GetInvalidFileNameChars());
         private static HashSet<string> _invalidRootFileNames = new HashSet<string> { "$mft", "$mftmirr", "$logfile", "$volume", "$attrdef", "$bitmap", "$boot", "$badclus", "$secure", "$upcase", "$extend", "$quota", "$objid", "$reparse" };
         private static bool StartWithInvalidWindowsPrefix(string name)
+        {
+            if (name.Length >= 3)
             {
                 switch (name[0])
                 {
@@ -71,7 +73,7 @@ namespace ZeroLevel.Services.FileSystem
                                 {
                                     case 'x':
                                     case 'X':
-                                    return name[3] == '.';  // AUX.
+                                        return name.Length == 3 || name[3] == '.';  // AUX.
                                 }
                                 break;
                         }
@@ -86,10 +88,10 @@ namespace ZeroLevel.Services.FileSystem
                                 {
                                     case 'n':
                                     case 'N':
-                                    return name[3] == '.';  // CON.
+                                        return name.Length == 3 || name[3] == '.';  // CON.
                                     case 'm':
                                     case 'M':
-                                    return char.IsDigit(name[3]) && name[4] == '.'; // COM0 - COM9
+                                        return name.Length >= 4 && char.IsDigit(name[3]) && (name.Length == 4 || name[4] == '.'); // COM0 - COM9
                                 }
                                 break;
                         }
@@ -104,7 +106,7 @@ namespace ZeroLevel.Services.FileSystem
                                 {
                                     case 't':
                                     case 'T':
-                                    return char.IsDigit(name[3]) && name[4] == '.'; // LPT0 - LPT9
+                                        return name.Length >= 4 && char.IsDigit(name[3]) && (name.Length == 4 || name[4] == '.'); // LPT0 - LPT9
                                 }
                                 break;
                         }
@@ -119,7 +121,7 @@ namespace ZeroLevel.Services.FileSystem
                                 {
                                     case 'n':
                                     case 'N':
-                                    return name[3] == '.';  // PRN.
+                                        return name.Length == 3 || name[3] == '.';  // PRN.
                                 }
                                 break;
                         }
@@ -134,12 +136,13 @@ namespace ZeroLevel.Services.FileSystem
                                 {
                                     case 'l':
                                     case 'L':
-                                    return name[3] == '.';  // NUL.
+                                        return name.Length == 3 || name[3] == '.';  // NUL.
                                 }
                                 break;
                         }
                         break;
                 }
+            }
             return false;
         }