FileCopierTests.cs

[TestFixture]
public class FileCopierTests
{
    [Test]
    public void CopyFile_SourceFileExistsDestinationDirDoesNotExist_DestinationFileCopied()
    {
        // Arrange
        var mockFileSystem = new MockFileSystem();
        mockFileSystem.AddFile(@"c:\file.txt", MockFileData.NullObject);

        var cleanFileCopier = new CleanFileCopier(mockFileSystem);

        // Act
        cleanFileCopier.CopyFile(@"c:\file.txt", @"c:\users\borismod.net");

        // Assert
        Assert.IsTrue(mockFileSystem.File.Exists(@"c:\users\borismod.net\file.txt"));
    }
}