Fix instance calculation with after and interval

Closes: #71
JonasWanke · Feb 7, 2024 · 902b071 · 902b071
1 parent 28b09bc
commit 902b071
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/lib/src/iteration/iteration.dart b/lib/src/iteration/iteration.dart
@@ -31,8 +31,7 @@ Iterable<DateTime> getRecurrenceRuleInstances(
   var count = rrule.count;
 
   var currentStart = start;
-
-  if (count == null && after != null) {
+  if (rrule.actualInterval == 1 && count == null && after != null) {
     // Shortcut for not calculating unnecessary recurrences.
     currentStart = after;
   }

diff --git a/test/recurrence_rule_test.dart b/test/recurrence_rule_test.dart
@@ -310,4 +310,17 @@ void main() {
       ]),
     );
   });
+  test("#71: Counting of interval starts from 'after', not from 'start'", () {
+    final rule =
+        RecurrenceRule.fromString('RRULE:FREQ=WEEKLY;INTERVAL=2;BYDAY=SU');
+    final start = DateTime.utc(2024, 2, 7);
+    expect(
+      rule.getInstances(start: start).take(2),
+      equals([DateTime.utc(2024, 2, 11), DateTime.utc(2024, 2, 25)]),
+    );
+    expect(
+      rule.getInstances(start: start, after: DateTime.utc(2024, 2, 12)).take(2),
+      equals([DateTime.utc(2024, 2, 25), DateTime.utc(2024, 3, 10)]),
+    );
+  });
 }