public void InsertTest()
{
SchoolDay schoolDay = new SchoolDay();
// first
int count = schoolDay.Count;
DateTime start = schoolDay.Start;
Lesson lesson1 = new Lesson(schoolDay.Start);
schoolDay.Insert(0, lesson1);
Assert.Equal <int>(schoolDay.Count, count + 1);
Assert.Equal(schoolDay[0], lesson1);
Assert.Equal(schoolDay.First, lesson1);
Assert.Equal(schoolDay.Start, start.Subtract(lesson1.Duration));
Assert.Equal(lesson1.Start, schoolDay.Start);
Assert.Equal <DateTime>(lesson1.End, start);
Assert.Equal <TimeSpan>(lesson1.Duration, Lesson.LessonDuration);
// inside
count = schoolDay.Count;
start = schoolDay.Start;
ShortBreak shortBreak1 = new ShortBreak(schoolDay.Start);
schoolDay.Insert(1, shortBreak1);
Assert.Equal <int>(schoolDay.Count, count + 1);
Assert.Equal(schoolDay[1], shortBreak1);
Assert.Equal(schoolDay.First, lesson1);
Assert.Equal <DateTime>(schoolDay.Start, start);
Assert.Equal(shortBreak1.Start, schoolDay.Start.Add(lesson1.Duration));
Assert.Equal <TimeSpan>(shortBreak1.Duration, ShortBreak.ShortBreakDuration);
// last
count = schoolDay.Count;
DateTime end = schoolDay.End;
ShortBreak shortBreak2 = new ShortBreak(schoolDay.Start);
schoolDay.Insert(schoolDay.Count, shortBreak2);
Assert.Equal <int>(schoolDay.Count, count + 1);
Assert.Equal(schoolDay[count], shortBreak2);
Assert.Equal(schoolDay.Last, shortBreak2);
Assert.Equal(schoolDay.End, shortBreak2.End);
Assert.Equal <DateTime>(shortBreak2.Start, end);
Assert.Equal <TimeSpan>(shortBreak2.Duration, ShortBreak.ShortBreakDuration);
} // InsertTest
