Materializers

Materializers are classes in this library that materialize resources to files. You might want to do this for a set of unit tests that operate on files rather than embedded resources directly. There are two classes for this, both implement IDisposable to enable cleanup of temporary files after use.

Both the temp file name and the temp directory name are composed of a generated guid with a .tmp extension.

TempFile

The TempFile class materializes a single resource to a file in the user's temp directory (Windows) or /tmp on other systems.

You can also use the TempFile constructor to directly create a temporary file from any valid Stream.

public class MyResourceClass : IDisposable
{
    [EmbeddedResource("MyResource.txt")]
    public TempFile FileResource { get; set; }

    public void Dispose()
    {
        this.FileResource?.Dispose();
    }
}

TempDirectory

The TempDirectory class materializes a project folder full of resources to a directory created in the user's temp directory (Windows) or /tmp on other systems.

Here, the path passed to the EmbeddedResource attribute is expected to unambiguously resolve to a folder in the project that contains one or more embedded resources. The file names and any subfolders within the selected folder are replicated to the temporary directory tree.

The TempDirectory also contains a default constructor that enables you to create a temporary directory for any purpose.

public class MyResourceClass : IDisposable
{
    [EmbeddedResource("Resources")]
    public TempDirectory Resources { get; set; }

    public void Dispose()
    {
        this.Resources?.Dispose();
    }
}

Caveats with TempDirectory

The compiler has a nasty trick when embedding folders into the resource manifest. These folders are effectively namespace names when committed to the assembly resource manifest and as such must confirm to .NET lexical structure rules for identifiers. All invalid characters as per this specification are replaced with underscore, and if the first character of the folder name is invalid, then an underscore is prefixed to the folder name.

To work around this, there is a property DirectoryRenames on EmbeddedResource that allows you to specify renames for directories that are being materialized.

Say you have this structure in your project

TempDirResource
+ sub-dir
  + file.txt

This will by default come out like this in the filesystem

TempDirResource
+ sub_dir
  + file.txt

To get the correct directory, do this

public class MyResourceClass : IDisposable
{
    [EmbeddedResource("Resources", DirectoryRenames = new[] { "sub_dir", "sub-dir"} )]
    public TempDirectory Resources { get; set; }

    public void Dispose()
    {
        this.Resources?.Dispose();
    }
}