public void PreviousDayTest() { TimeTool.PreviousDay(DayOfWeek.Monday).Should().Be(DayOfWeek.Sunday); TimeTool.PreviousDay(DayOfWeek.Tuesday).Should().Be(DayOfWeek.Monday); TimeTool.PreviousDay(DayOfWeek.Wednesday).Should().Be(DayOfWeek.Tuesday); TimeTool.PreviousDay(DayOfWeek.Thursday).Should().Be(DayOfWeek.Wednesday); TimeTool.PreviousDay(DayOfWeek.Friday).Should().Be(DayOfWeek.Thursday); TimeTool.PreviousDay(DayOfWeek.Saturday).Should().Be(DayOfWeek.Friday); TimeTool.PreviousDay(DayOfWeek.Sunday).Should().Be(DayOfWeek.Saturday); }