MockDirectory.Move should throw when target cannot be parsed (#573)

Fixes #551

Author: pianomanjh

System.IO.Abstractions.TestingHelpers.Tests/MockDirectoryTests.cs

@@ -1903,5 +1903,69 @@ public void MockDirectory_SetCreationTime_ShouldNotThrowWithoutTrailingBackslash
             fs.Directory.SetCreationTime(path, DateTime.Now);
             fs.Directory.Delete(path);
         }
+
+        [Test]
+        [TestCase(@"c:\temp2\fd\df")]
+        [TestCase(@"c:\temp2\fd\")]
+        [TestCase(@"c:\temp2\fd\..\fd")]
+        [TestCase(@"c:\temp2\fd")]
+        [TestCase(@".\..\temp2\fd\df")]
+        [TestCase(@".\..\temp2\fd\df\..")]
+        [TestCase(@".\..\temp2\fd\df\..\")]
+        [TestCase(@"..\temp2\fd\")]
+        [TestCase(@".\temp2\fd")]
+        [TestCase(@"\temp2\fd")]
+        [TestCase(@"temp2\fd")]
+        public void Move_Directory_Throws_When_Target_Directory_Without_First_Order_Path_Is_Missing(
+            string targetDirName)
+        {
+            // Arange
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                {XFS.Path(@"c:\temp\exists\foldertomove"), new MockDirectoryData()}
+            });
+
+            string folderToMove = XFS.Path(@"c:\temp\exists\foldertomove");
+            targetDirName = XFS.Path(targetDirName);
+
+            // Act
+            Assert.Throws<DirectoryNotFoundException>(() =>
+                fileSystem.Directory.Move(folderToMove, targetDirName));
+
+            // Assert
+            Assert.IsFalse(fileSystem.Directory.Exists(targetDirName));
+        }
+
+        [Test]
+        [TestCase(@"c:\temp2\")]
+        [TestCase(@"c:\temp2")]
+        [TestCase(@"c:\temp2\..\temp2")]
+        [TestCase(@".\..\temp2")]
+        [TestCase(@".\..\temp2\..\temp2")]
+        [TestCase(@".\..\temp2\fd\df\..\..")]
+        [TestCase(@".\..\temp2\fd\df\..\..\")]
+        [TestCase(@"..\temp2")]
+        [TestCase(@".\temp2")]
+        [TestCase(@"\temp2")]
+        [TestCase(@"temp2")]
+        public void Move_Directory_DoesNotThrow_When_Target_Directory_With_First_Order_Path_Is_Missing(
+            string targetDirName)
+        {
+            // Arange
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                {XFS.Path(@"c:\temp\exists\foldertomove"), new MockDirectoryData()}
+            });
+
+            string folderToMove = XFS.Path(@"c:\temp\exists\foldertomove");
+            targetDirName = XFS.Path(targetDirName);
+
+            // Act
+            Assert.DoesNotThrow(() =>
+                fileSystem.Directory.Move(folderToMove, targetDirName));
+
+            // Assert
+            Assert.IsTrue(fileSystem.Directory.Exists(targetDirName));
+        }
     }
 }

System.IO.Abstractions.TestingHelpers/MockDirectory.cs

@@ -415,6 +415,11 @@ public override void Move(string sourceDirName, string destDirName)
                 throw new DirectoryNotFoundException($"Could not find a part of the path '{sourceDirName}'.");
             }
 
+            if (!Win32FileSystemBehavior.MoveFileCanParsePath(fullDestPath))
+            {
+                throw new DirectoryNotFoundException($"Could not find a part of the path.");
+            }
+
             if (mockFileDataAccessor.Directory.Exists(fullDestPath) || mockFileDataAccessor.File.Exists(fullDestPath))
             {
                 throw new IOException($"Cannot create '{fullDestPath}' because a file or directory with the same name already exists.");

System.IO.Abstractions.TestingHelpers/Win32FileSystemBehavior.cs

@@ -0,0 +1,17 @@
+namespace System.IO.Abstractions.TestingHelpers
+{
+    internal static class Win32FileSystemBehavior
+    {
+        public static bool MoveFileCanParsePath(string fullPath)
+        {
+            fullPath = fullPath.Trim(Path.DirectorySeparatorChar);
+            var dir = Path.IsPathRooted(fullPath)
+                ? fullPath.Replace(Path.GetPathRoot(fullPath), string.Empty)
+                : fullPath.Replace($".{Path.DirectorySeparatorChar}", string.Empty);
+
+            const int DirectorySegmentsAllowed = 1;
+            var isSupported = dir.Split(Path.DirectorySeparatorChar).Length <= DirectorySegmentsAllowed;
+            return isSupported;
+        }
+    }        
+}