Fix issue #41

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.5.1
+
+- Fixed scheduling issue. [#42](https://github.com/agilord/cron/issues/42) by [ccl0326](https://github.com/ccl0326)
+
 ## 0.5.0
 
 - Improved time parsing.　[#21](https://github.com/agilord/cron/issues/21) by [myConsciousness](https://github.com/myConsciousness)

lib/cron.dart

@@ -193,11 +193,23 @@ class _ScheduledTask implements ScheduledTask {
   Future? _running;
   bool _overrun = false;
 
+  /// The datetime a Task last run.
+  DateTime lastTime = DateTime(0, 0, 0, 0, 0, 0, 0);
+
   _ScheduledTask(this.schedule, this._task);
 
   void tick(DateTime now) {
     if (_closed) return;
     if (!schedule.shouldRunAt(now)) return;
+    if ((schedule.seconds == null || lastTime.second == now.second) &&
+        (schedule.minutes == null || lastTime.minute == now.minute) &&
+        (schedule.hours == null || lastTime.hour == now.hour) &&
+        (schedule.days == null || lastTime.day == now.day) &&
+        (schedule.months == null || lastTime.month == now.month) &&
+        (schedule.weekdays == null || lastTime.weekday == now.weekday)) {
+      return;
+    }
+    lastTime = now;
     _run();
   }
 

lib/src/constraint_parser.dart

@@ -3,7 +3,8 @@ List<int>? parseConstraint(dynamic constraint) {
   if (constraint is int) return [constraint];
   if (constraint is List<int>) return constraint;
   if (constraint is String) {
-    if (constraint == '*' || constraint == '') return null;
+    if (constraint == '*') return List.generate(60, (i) => i);
+    if (constraint == '') return null;
     final parts = constraint.split(',');
     if (parts.length > 1) {
       final items =

pubspec.yaml

@@ -1,6 +1,6 @@
 name: cron
 description: A time-based job scheduler similar to cron. Run tasks periodically at fixed times or intervals.
-version: 0.5.0
+version: 0.5.1
 homepage: https://github.com/agilord/cron
 
 environment: