public void Should_Throw_If_Folder_Is_Null()
            {
                // Given
                var scanner = new FolderScannerFixture().CreateScanner();

                // When
                var exception = Record.Exception(() => scanner.Scan(null));

                // Then
                Assert.IsType<ArgumentNullException>(exception);
                Assert.Equal("folder", ((ArgumentNullException) exception).ParamName);
            }
            public void Should_Not_Throw_If_Folder_Does_Not_Exist()
            {
                // Given
                var fixture = new FolderScannerFixture();
                var scanner = fixture.CreateScanner();

                // When
                var exception = Record.Exception(() => scanner.Scan(new Folder {Path = "C:\\Non-existing"}));

                // Then
                fixture.FileSystem.GetDirectory("C:\\Non-existing").Received(1);
                Assert.Null(exception);
            }