public async void Should_Change_Process_Working_Directory(string dir, string expected)
            {
                // Given
                var fixture = new MkDocsServeAsyncRunnerFixture();

                fixture.GivenProjectDirectory(dir);

                // When
                var result = await fixture.Run();

                // Then
                Assert.Equal(expected, result.Process.WorkingDirectory.FullPath);
            }
            public async void Should_Throw_For_Empty_Project_Dir()
            {
                // Given
                var fixture = new MkDocsServeAsyncRunnerFixture();

                fixture.GivenProjectDirectory(null);

                // When
                var result = await(Record.ExceptionAsync(() => fixture.Run()) ?? Task.FromResult <Exception>(null));

                // Then
                Assert.IsType <ArgumentNullException>(result);
                Assert.Equal("projectDirectory", ((ArgumentNullException)result).ParamName);
            }