MockFileSystem created file don't exist

[milten89]

Describe the bug
From version 16.0.8 of System.IO.Abstractions.TestingHelpers when I create new file in MockFileSystem property Exist return false.

To Reproduce

IFileSystem fileSystem = new MockFileSystem();
IFileInfo fileInfo = fileSystem.FileInfo.FromFileName("testFile.txt");
using (Stream fs = fileInfo.Create()) 
{
 fs.WriteByte(0);
}
Console.WriteLine($"File exist: {fileInfo.Exists}");

Version 16.0.7 return True
Version 16.0.8 return False

Expected behavior
Property Exist should return True

[fgreinacher]

@milten89 Thanks for taking the time to report this!

The behavior of MockFileInfo has changed in #791 to mirror the behavior of the real file system (see #661).

Could you please check how your code behaves with the real file system?

[milten89]

@fgreinacher there is difference in output for FileSystem and MockFileSystem.

public static void Main(string[] args)
{
 IFileSystem realFileSystem = new FileSystem();
 IFileSystem mockFileSystem = new MockFileSystem();
 Console.WriteLine($"Real file exist: {TestFileSystem(realFileSystem)}");
 Console.WriteLine($"Fake file exist: {TestFileSystem(mockFileSystem)}");
 Console.ReadLine();
}

private static bool TestFileSystem(IFileSystem fileSystem)
{
 IFileInfo fileInfo = null; 
 try
 {
 fileInfo = fileSystem.FileInfo.FromFileName("testFile.txt");
 using (Stream fs = fileInfo.Create()) 
 fs.WriteByte(0);

 return fileInfo.Exists;
 }
 finally
 {
 if (fileInfo != null && fileInfo.Exists)
 fileInfo.Delete();
 }
}

Starts from version 16.0.8 FileSystem return True and MockFileSystem return False.
In latest version 16.1.23 result is same.

Additional to that, there is difference in paths for FileSystem and MockFileSystem.

• FileSystem:

C:\Users\Andrzej Ochodek\source\repos\FileSystemAbstractionTest\FileSystemAbstractionTest\bin\Debug\testFile.txt

• MockFileSystem:

C:\testFile.txt

[milten89]

Are there any updates about this bug?

[fgreinacher]

Are there any updates about this bug?

Sorry, I lost track of this one.

Starts from version 16.0.8 FileSystem return True and MockFileSystem return False.
In latest version 16.1.23 result is same.

Do I understand correctly that everything is working as expected in 16.1.23?

Additional to that, there is difference in paths for FileSystem and MockFileSystem.

That's expected/by-design, because the MockFileSystem is initialized with the root directory (/ on Unix, C:\ on Windows).

[milten89]

Do I understand correctly that everything is working as expected in 16.1.23?

Unfortunately no. Real file system returns true and mock returns false.

That's expected/by-design, because the MockFileSystem is initialized with the root directory (/ on Unix, C:\ on Windows).

Ok.

[siprbaum]

I created a pull request to fix it, see #828

[github-actions]

This is addressed in release v16.1.24.