Merge pull request #203 from peek-travel/hotfix/fix-infinite-loop

Infinite loop possible if "end time" is within "duration" of midnight

lib/cocktail/validation/time_range.ex

@@ -28,12 +28,19 @@ defmodule Cocktail.Validation.TimeRange do
   defp generate_times(%__MODULE__{} = time_range) do
     time_range.start_time
     |> Stream.unfold(fn time ->
-      case Time.compare(time, time_range.end_time) do
-        :gt ->
+      current_gt_end = Time.compare(time, time_range.end_time)
+      next_time = Time.add(time, time_range.interval_seconds)
+      current_gt_next = Time.compare(time, next_time)
+
+      case {current_gt_end, current_gt_next} do
+        {:gt, _} ->
+          nil
+
+        {_, :gt} ->
           nil
 
         _ ->
-          {time, Time.add(time, time_range.interval_seconds)}
+          {time, next_time}
       end
     end)
     |> Enum.to_list()

mix.exs

@@ -1,7 +1,7 @@
 defmodule Cocktail.Mixfile do
   use Mix.Project
 
-  @version "0.10.0"
+  @version "0.10.1"
 
   def project do
     [

test/cocktail/schedule_test.exs

@@ -70,6 +70,23 @@ defmodule Cocktail.ScheduleTest do
     assert times == [~N[2017-09-09 09:00:00]]
   end
 
+  test "occurrences at the end of the day won't cause an infinite loop" do
+    assert [%{from: ~N[2021-10-15 23:00:00], until: ~N[2021-10-15 23:30:00]}] =
+             ~N[2021-10-15 23:00:00]
+             |> Schedule.new(duration: 1800)
+             |> Schedule.add_recurrence_rule(
+               :daily,
+               time_range: %{
+                 start_time: ~T[23:00:00],
+                 end_time: ~T[23:55:00],
+                 interval_seconds: 1800
+               },
+               until: ~N[2021-10-15 23:55:00]
+             )
+             |> Schedule.occurrences()
+             |> Enum.to_list()
+  end
+
   test "add recurrence rule with bad options" do
     schedule =
       ~N[2017-09-09 09:00:00]