private void When_writing_to_existing_file_it_must_update_file_timings() { // Arrange const string path = @"C:\some\file.txt"; DateTime creationTimeUtc = 17.March(2006).At(14, 03, 53).AsUtc(); var clock = new SystemClock(() => creationTimeUtc); IFileSystem fileSystem = new FakeFileSystemBuilder(clock) .IncludingEmptyFile(path) .Build(); DateTime changeTimeUtc = 18.March(2006).At(14, 03, 53).AsUtc(); clock.UtcNow = () => changeTimeUtc; // Act fileSystem.File.WriteAllBytes(path, BufferFactory.SingleByte(0xFF)); // Assert fileSystem.File.GetCreationTimeUtc(path).Should().Be(creationTimeUtc); fileSystem.File.GetLastWriteTimeUtc(path).Should().Be(changeTimeUtc); fileSystem.File.GetLastAccessTimeUtc(path).Should().Be(changeTimeUtc); }