File System

Serenity provides a small file system abstraction so that file and directory operations can be mocked or replaced in tests, and so that code doesn't depend directly on System.IO.

IFileSystem

IFileSystem is the base abstraction. It covers the common file and directory operations you'd expect:

• CreateFile / CreateDirectory
• DeleteFile / DeleteDirectory
• FileExists / DirectoryExists
• GetFiles / GetDirectories (with search pattern and recursive options)
• GetFileSize
• ReadAllText / ReadAllBytes / WriteAllText / WriteAllBytes
• OpenRead
• GetFullPath / GetRelativePath / GetLastWriteTimeUtc

Because it's an interface, you can replace it with a mock or an in-memory implementation in tests.

PhysicalFileSystem

PhysicalFileSystem is the default implementation that operates on the physical disk, delegating to System.IO.

IFileSystem is not registered in the DI container by default. You typically construct it directly or accept it as an optional constructor parameter:

public class SomeService(IFileSystem fileSystem = null)
{
    private readonly IFileSystem fileSystem = fileSystem ?? new PhysicalFileSystem();
}

This lets callers pass a mock file system in tests while defaulting to the physical disk.

FileSystemExtensions

FileSystemExtensions provides extension methods on IFileSystem that delegate to System.IO.Path helpers (e.g. Combine, GetFileName, GetExtension, ChangeExtension, GetDirectoryName, IsPathRooted). This reduces direct dependency on System.IO in case those methods are later added to IFileSystem.

Temporary Files

Serenity has a dedicated abstraction and helpers for temporary files and folders.

ITemporaryFileSystem

ITemporaryFileSystem extends IFileSystem with GetTemporaryFileInfos(path), which returns TemporaryFileInfo objects (file name, full name, and creation time) for the files in a directory.

TemporaryFileHelper

TemporaryFileHelper is a static helper for cleaning up temporary folders. It's used by the upload system to purge old temporary uploads.

Key members:

• DefaultTemporaryCheckFile (.temporary) — a signature file that marks a folder as a temporary folder, so it can be safely cleaned.
• DefaultAutoExpireTime (1 day) — files older than this are cleared.
• DefaultMaxFilesInDirectory (1000) — if more than this many files exist, the oldest are deleted.
• PurgeDirectoryDefault(directory) — clears a folder using the default conditions.
• PurgeDirectory(directory, autoExpireTime, maxFilesInDirectory, checkFileName) — clears a folder with custom conditions.
• Delete / TryDelete / TryDeleteOrMark — delete a file, optionally ignoring errors or marking it for later deletion.
• RandomFileCode() — generates a random file code (used for temporary file names).

The cleanup is safe: it only operates on folders that contain the .temporary signature file, and it ignores individual deletion errors.

DeleteType

DeleteType specifies how a file should be deleted:

Value	Behavior
Delete	Force delete the file
TryDelete	Try to delete, ignoring any errors
TryDeleteOrMark	Try to delete, or mark it for deletion if it can't be deleted

GlobFilter

GlobFilter is a fast glob matcher compatible with .gitignore patterns. It supports include and exclude pattern lists:

var filter = new GlobFilter(
    include: ["*.txt", "*.md"],
    exclude: ["**/obj/**", "**/bin/**"]);

if (filter.IsMatch("some/file.txt"))
    // ...

It's used internally for things like filtering files in a directory tree.

See Also

• Uploads — uses IFileSystem and TemporaryFileHelper for upload storage and temp cleanup
• Dependency Injection — IServiceResolver and service resolution