Improve #132

Author: maennchen

lib/crontab/cron_expression.ex

@@ -43,6 +43,7 @@ defmodule Crontab.CronExpression do
              | min_max(time_unit), pos_integer}
           | min_max(time_unit)
           | {:W, time_unit | :L}
+          | {:"#", time_unit, pos_integer}
 
   @typedoc deprecated: "Use Calendar.second/0 instead"
   @type second :: Calendar.second()

lib/crontab/date_helper.ex

@@ -56,7 +56,7 @@ defmodule Crontab.DateHelper do
   """
   @spec nth_weekday(NaiveDateTime.t(), Calendar.day_of_week(), pos_integer()) ::
           Calendar.day() | nil
-  def nth_weekday(%{month: month} = date, weekday, n),
+  def nth_weekday(date = %{month: month}, weekday, n),
     do: find_nth_weekday(%{date | day: 1}, month, weekday, n)
 
   @doc """
@@ -182,7 +182,7 @@ defmodule Crontab.DateHelper do
           weekday :: Calendar.day_of_week(),
           n :: non_neg_integer()
         ) :: Calendar.day() | nil
-  defp find_nth_weekday(%{month: month} = date, month, weekday, n) do
+  defp find_nth_weekday(date = %{month: month}, month, weekday, n) do
     modifier =
       if Date.day_of_week(date) == weekday,
         do: n - 1,

test/crontab/functional_test.exs

@@ -130,7 +130,9 @@ defmodule Crontab.FunctionalTest do
     {"* * * * 5#1", "* * * * 5#1 *", ~N[2011-07-01 00:00:00], ~N[2011-07-01 00:00:00],
      ~N[2011-07-01 00:00:00], true},
     {"* * * * 3#4", "* * * * 3#4 *", ~N[2011-07-01 00:00:00], ~N[2011-07-27 00:00:00],
-     ~N[2011-06-22 23:59:00], false}
+     ~N[2011-06-22 23:59:00], false},
+    {"0 9 * * mon#5", "0 9 * * 1#5 *", ~N[2024-10-22 09:00:00], ~N[2024-12-30 09:00:00],
+     ~N[2024-09-30 09:00:00], false}
   ]
 
   for {cron_expression, written_cron_expression, start_date, next_search_date,
@@ -149,17 +151,25 @@ defmodule Crontab.FunctionalTest do
       {:ok, cron_expression} = Parser.parse(@cron_expression)
       assert Composer.compose(cron_expression) == @written_cron_expression
 
-      assert Crontab.Scheduler.get_next_run_date(cron_expression, @start_date) ==
-               {:ok, @next_search_date}
+      assert {:ok, next_search_date} =
+               Crontab.Scheduler.get_next_run_date(cron_expression, @start_date)
+
+      assert Crontab.DateChecker.matches_date?(cron_expression, next_search_date)
+
+      assert next_search_date == @next_search_date
 
       case @previous_search_date do
         :none ->
           assert Crontab.Scheduler.get_previous_run_date(cron_expression, @start_date) ==
                    {:error, "No compliant date was found for your interval."}
 
         _ ->
-          assert Crontab.Scheduler.get_previous_run_date(cron_expression, @start_date) ==
-                   {:ok, @previous_search_date}
+          assert {:ok, previous_search_date} =
+                   Crontab.Scheduler.get_previous_run_date(cron_expression, @start_date)
+
+          assert Crontab.DateChecker.matches_date?(cron_expression, previous_search_date)
+
+          assert previous_search_date == @previous_search_date
       end
 
       assert Crontab.DateChecker.matches_date?(cron_expression, @start_date) == @matches_now