Add option to specify Cron Job with Seconds

src/Extensions/NetDaemon.Extensions.Scheduling.Tests/Scheduling/CronTests.cs

@@ -16,6 +16,7 @@ public void TestCron()
     {
         var count = 0;
         var sched = new TestScheduler();
+
         sched.AdvanceTo(DateTime.UtcNow.Ticks);
 
         var sub = sched.ScheduleCron("0 * * * *", () => count++);
@@ -25,15 +26,49 @@ public void TestCron()
 
         sched.AdvanceBy(TimeSpan.FromHours(1).Ticks);
         count.Should().Be(2);
-        
+
         sched.AdvanceBy(TimeSpan.FromHours(1).Ticks);
         count.Should().Be(3);
 
         sub.Dispose();
         sched.AdvanceBy(TimeSpan.FromHours(1).Ticks);
         count.Should().Be(3, because: "Action should not fire after Dispose()");
     }
-
+
+    [Fact]
+    public void TestCronSeconds()
+    {
+        var count = 0;
+        var sched = new TestScheduler();
+
+        sched = new TestScheduler();
+        count = 0;
+        sched.AdvanceTo(new DateTime(2020, 2, 3, 8, 0, 28).Ticks);
+        var subSec = sched.ScheduleCron("*/30 0 * * * *", () => count++, hasSeconds: true); // 0 and 30 seconds after every whole hour 
+
+        sched.AdvanceTo(new DateTime(2020, 2, 3, 8, minute: 0, second: 29).Ticks);
+        count.Should().Be(0);
+
+        sched.AdvanceTo(new DateTime(2020, 2, 3, 8, minute: 0, second: 30).Ticks);
+        count.Should().Be(1);
+
+        sched.AdvanceTo(new DateTime(2020, 2, 3, 8, minute: 1, second: 1).Ticks);
+        count.Should().Be(1);
+
+        sched.AdvanceBy(TimeSpan.FromMinutes(10).Ticks);
+        count.Should().Be(1);
+
+        sched.AdvanceTo(new DateTime(2020, 2, 3, 9, minute: 0, second: 0).Ticks);
+        count.Should().Be(2);
+
+        sched.AdvanceTo(new DateTime(2020, 2, 3, 9, minute: 0, second: 30).Ticks);
+        count.Should().Be(3);
+
+        subSec.Dispose();
+        sched.AdvanceBy(TimeSpan.FromHours(1).Ticks);
+        count.Should().Be(3, because: "Action should not fire after Dispose()");
+    }
+
     [Fact]
     public void ContinueAfterActionThrows()
     {

src/Extensions/NetDaemon.Extensions.Scheduling/CronExtensions.cs

@@ -17,15 +17,17 @@ public static class CronExtensions
     /// <param name="scheduler">IScheduler to use for this action</param>
     /// <param name="cron">Cron expression that describes the schedule</param>
     /// <param name="action">Callback to execute</param>
+    /// <param name="hasSeconds">True if cron has Seconds specified</param>
     /// <returns>Disposable object that allows the schedule to be cancelled</returns>
-    public static IDisposable ScheduleCron(this IScheduler scheduler, string cron, Action action)
+    public static IDisposable ScheduleCron(this IScheduler scheduler, string cron, Action action, bool hasSeconds = false)
     {
         ArgumentNullException.ThrowIfNull(scheduler);
-
+
+        var format = hasSeconds ? CronFormat.IncludeSeconds : CronFormat.Standard;
         // When this gets cancelled we only need to actually dispose of the most recent scheduled action
         // (there will only be one at a time) so we store that in a box we will pass down
         StrongBox<IDisposable?> disposableBox = new();
-        RecursiveSchedule(scheduler, CronExpression.Parse(cron), action, disposableBox, scheduler.Now);
+        RecursiveSchedule(scheduler, CronExpression.Parse(cron, format), action, disposableBox, scheduler.Now);
 
         // Dispose will Dispose the IDisposable in the box
         return Disposable.Create(()=> disposableBox.Value?.Dispose());