fix: do not move unrelated files with same prefix (#665)

Fixes #664 

Co-authored-by: Marco Eisenring <Marco.Eisenring@advellence.com>
Co-authored-by: Florian Greinacher <fgreinacher@users.noreply.github.com>
Co-authored-by: Florian Greinacher <florian@greinacher.de>

Author: 3 people

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

@@ -239,10 +239,12 @@ public void MoveDirectory(string sourcePath, string destPath)
             sourcePath = FixPath(sourcePath);
             destPath = FixPath(destPath);
 
+            var sourcePathSequence = sourcePath.Split(new[] {Path.DirectorySeparatorChar}, StringSplitOptions.RemoveEmptyEntries);
+
             lock (files)
             {
                 var affectedPaths = files.Keys
-                    .Where(p => StringOperations.StartsWith(p, sourcePath))
+                    .Where(p => PathStartsWith(p, sourcePathSequence))
                     .ToList();
 
                 foreach (var path in affectedPaths)
@@ -252,6 +254,25 @@ public void MoveDirectory(string sourcePath, string destPath)
                     files.Remove(path);
                 }
             }
+
+            bool PathStartsWith(string path, string[] minMatch)
+            {
+                var pathSequence = path.Split(new[] {Path.DirectorySeparatorChar}, StringSplitOptions.RemoveEmptyEntries);
+                if (pathSequence.Length < minMatch.Length)
+                {
+                    return false;
+                }
+
+                for (var i = 0; i < minMatch.Length; i++)
+                {
+                    if (!StringOperations.Equals(minMatch[i], pathSequence[i]))
+                    {
+                        return false;
+                    }
+                }
+
+                return true;
+            }
         }
 
         public void RemoveFile(string path)

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

@@ -1461,6 +1461,27 @@ public void MockDirectory_Move_ShouldMoveDirectoryWithReadOnlySubDirectory()
             Assert.IsTrue(fileSystem.FileExists(destSubDirName));
         }
 
+        [Test]
+        public void MockDirectory_Move_ShouldOnlyMoveDirAndFilesWithinDir()
+        {
+            // Arrange
+            var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>
+            {
+                {XFS.Path(@"c:\source\dummy"), new MockDirectoryData()},
+                {XFS.Path(@"c:\source\dummy\content.txt"), new MockFileData(new byte[] {0})},
+                {XFS.Path(@"c:\source\dummy.txt"), new MockFileData(new byte[] {0})},
+                {XFS.Path(@"c:\source\dummy2"), new MockDirectoryData()},
+                {XFS.Path(@"c:\destination"), new MockDirectoryData()},
+            });
+
+            // Act
+            fileSystem.Directory.Move(XFS.Path(@"c:\source\dummy"), XFS.Path(@"c:\destination\dummy"));
+
+            // Assert
+            Assert.That(fileSystem.FileExists(XFS.Path(@"c:\source\dummy.txt")), Is.True);
+            Assert.That(fileSystem.Directory.Exists(XFS.Path(@"c:\source\dummy2")), Is.True);
+        }
+
         [Test]
         public void MockDirectory_GetCurrentDirectory_ShouldReturnValueFromFileSystemConstructor()
         {