public void FolderAbsolutePath_Happy()
        {
            FolderAbsolutePath folder = FilesFolder + "/happy";

            folder.AppendPath(null).Should().Be(folder);
            folder.AppendPath("bla").Should().Be(Path.Combine(folder, "bla"));
        }
        public void FolderAbsolutePath_Folder_DoesntExist()
        {
            var folder = FilesFolder + "happyAAA";
            var ex     = Assert.Throws <ArgumentException>(() => { FolderAbsolutePath target = folder; });

            ex.Message.Should().Be($"Folder does not exist: {folder}");
        }
        public void FolderAbsolutePath_Empty_Unhappy()
        {
            var ex = Assert.Throws <ArgumentNullException>(() => { FolderAbsolutePath file = "    "; });

            ex.Message.Should().Be("Value cannot be null. (Parameter 'value')");
        }