public void GetNextDayOfMonth
(
DateTime after,
int dayOfMonth,
UnrepresentableDateHandling unrepresentableDateHandling,
DateTime?[] expected
)
{
var result = DayOfMonthTrigger
.GetNextDayOfMonth(after, dayOfMonth, unrepresentableDateHandling)?
.ToArray();
Assert.IsNotNull(result);
Assert.AreEqual(expected.Length, result.Length);
for (var i = 0; i < result.Length; i++)
{
Assert.AreEqual(expected[i], result[i]);
}
}
/// <summary>
/// Helper method to return the next potential run date within a schedule.
/// </summary>
/// <param name="after">The day to start looking on.</param>
/// <param name="dayOfMonth">The day of the month to return.</param>
/// <returns>
/// If <paramref name="after"/> is the same day as <paramref name="dayOfWeek"/> then will return
/// two items - one for today and one for the same day month.
/// If not then it will return one item - for the next time that this day occurs
/// (later this month or next, depending on parameters).
/// </returns>
internal static IEnumerable <DateTime> GetNextDayOfMonth
(
DateTime after,
int dayOfMonth,
UnrepresentableDateHandling unrepresentableDateHandling
)
{
// If the day of the month is invalid then return no values.
if (dayOfMonth < 1 || dayOfMonth > 32)
{
yield break;
}
// Switch logic depending on the current day.
if (dayOfMonth == after.Day)
{
// It's today.
// We could be running today or the same day next month (depending on trigger times).
// Return both options.
yield return(after.Date);
yield return
(new DateTime(after.Year, after.Month, 1)
.AddMonths(1) // One month
.AddDays(dayOfMonth - 1)); // Move forward to the correct day.
}
else if (dayOfMonth < after.Day)
{
// This day has already passed.
// Return the correct day next month.
yield return(new DateTime(after.Year, after.Month, dayOfMonth).AddMonths(1));
}
else
{
// Day is in the future this month.
var sanity = 0;
var month = after.Month;
while (sanity++ < 6)
{
DateTime?date = null;
try
{
// Can we represent this date?
// If not then we've asked for 30th Feb or similar.
date = new DateTime(after.Year, month, dayOfMonth);
}
catch
{
// What should we do?
switch (unrepresentableDateHandling)
{
case UnrepresentableDateHandling.LastDayOfMonth:
// Get the last day of this month instead.
date = new DateTime(after.Year, month, 1)
.AddMonths(1)
.AddDays(-1);
break;
default:
// Allow it to try the next month.
date = null;
month++;
break;
}
}
// If we can represent it then return it, otherwise move to next month.
if (date.HasValue)
{
yield return(date.Value);
break;
}
}
}
}
