term month generation is correct

Management.Test/Features/SemesterPlannerTests.cs

@@ -49,4 +49,39 @@ public class SemesterPlannerTests
     semester.Months.Count().Should().Be(2);
   }
 
+  [Test]
+  public void TestSemesterGetsCorrectMonths()
+  {
+    var canvasTerm = new EnrollmentTermModel(
+      Id: 1,
+      Name: "one",
+      StartAt: new DateTime(2022, 1, 1),
+      EndAt: new DateTime(2022, 2, 1)
+    );
+
+    var semester = new SemesterPlanner(canvasTerm);
+
+    semester.Months.First().Month.Should().Be(1);
+    semester.Months.Last().Month.Should().Be(2);
+  }
+
+
+  [Test]
+  public void TestMonthsCanWrapYears()
+  {
+    var canvasTerm = new EnrollmentTermModel(
+      Id: 1,
+      Name: "one",
+      StartAt: new DateTime(2022, 12, 1),
+      EndAt: new DateTime(2023, 1, 1)
+    );
+
+    var semester = new SemesterPlanner(canvasTerm);
+
+    semester.Months.First().Month.Should().Be(12);
+    semester.Months.First().Year.Should().Be(2022);
+
+    semester.Months.Last().Month.Should().Be(1);
+    semester.Months.Last().Year.Should().Be(2023);
+  }
 }

Management/Features/Calendar/CalendarMonth.cs

@@ -1,8 +1,7 @@
 public class CalendarMonth
 {
-  private DateOnly firstDay { get; }
+  public int Year { get; }
-  private int year { get => firstDay.Year; }
+  public int Month { get; }
-  private int month { get => firstDay.Month; }
   public IEnumerable<IEnumerable<int?>> Weeks
   {
     get =>
@@ -17,10 +16,10 @@ public class CalendarMonth
     get
     {
       var weeks = new List<List<DateTime?>>();
-      var weeksInMonth = WeeksInMonth(year, month);
+      var weeksInMonth = WeeksInMonth(Year, Month);
-      var daysInMonth = DateTime.DaysInMonth(year, month);
+      var daysInMonth = DateTime.DaysInMonth(Year, Month);
 
-      var firstDayOfMonth = new DateTime(year, month, 1).DayOfWeek;
+      var firstDayOfMonth = new DateTime(Year, Month, 1).DayOfWeek;
 
       var currentDay = 1;
       for (int i = 0; i < weeksInMonth; i++)
@@ -36,7 +35,7 @@ public class CalendarMonth
             }
             else
             {
-              thisWeek.Add(new DateTime(year, month, currentDay));
+              thisWeek.Add(new DateTime(Year, Month, currentDay));
               currentDay++;
             }
           }
@@ -47,7 +46,7 @@ public class CalendarMonth
           {
             if (currentDay <= daysInMonth)
             {
-              thisWeek.Add(new DateTime(year, month, currentDay));
+              thisWeek.Add(new DateTime(Year, Month, currentDay));
               currentDay++;
             }
             else
@@ -77,7 +76,7 @@ public class CalendarMonth
 
   public CalendarMonth(int year, int month)
   {
-    firstDay = new DateOnly(year, month, 1);
+    Year = year;
-
+    Month = month;
   }
 }

Management/Features/Calendar/SemesterPlanner.cs

@@ -5,11 +5,20 @@ public class SemesterPlanner
   public IEnumerable<CalendarMonth> Months { get; }
   public SemesterPlanner(EnrollmentTermModel canvasTerm)
   {
-    var monthsInTerm =
+    var start = canvasTerm.StartAt ?? throw new Exception($"Canvas Term must have a start date. Term: {canvasTerm.Id}");
-      1 + ((canvasTerm.EndAt?.Year - canvasTerm.StartAt?.Year) * 12)
+    var end = canvasTerm.EndAt ?? throw new Exception($"Canvas Term must have a end date. Term: {canvasTerm.Id}");
-        + canvasTerm.EndAt?.Month - canvasTerm.StartAt?.Month
-      ?? throw new Exception($"Canvas Term must have a start and end date. Term: {canvasTerm.Id}, start: {canvasTerm.StartAt}, end: {canvasTerm.EndAt}");
 
-    Months = Enumerable.Range(0, monthsInTerm).Select(_ => new CalendarMonth(2022, 1));
+    var monthsInTerm =
+      1 + ((end.Year - start.Year) * 12)
+        + end.Month - start.Month;
+
+    Months = Enumerable
+      .Range(0, monthsInTerm)
+      .Select(monthDiff =>
+      {
+        var month = ((start.Month + monthDiff - 1) % 12) + 1;
+        var year = start.Year + ((start.Month + monthDiff - 1) / 12);
+        return new CalendarMonth(year, month);
+      });
   }
 }