Support day-only intervals in Shared.Zeitperiode.parse/1

Co-authored-by: Ona <no-reply@ona.com>

Author: SilvanCodes

lib/zeit.ex

@@ -64,6 +64,12 @@ defmodule Shared.Zeit do
 
       {:ok, %NaiveDateTime{} = naive_date_time} ->
         naive_date_time
+
+      {:error, _} ->
+        case Date.from_iso8601(to_parse) do
+          {:ok, date} -> NaiveDateTime.new!(date, ~T[00:00:00])
+          {:error, reason} -> raise ArgumentError, "Invalid date/time format: #{reason}"
+        end
     end
   end
 

lib/zeit_test.exs

@@ -33,6 +33,27 @@ defmodule Shared.ZeitTest do
              |> Timex.to_datetime("Etc/UTC")
              |> entspricht_timestamp?("2018-10-03T10:20:42Z")
     end
+
+    test "parse date-only string" do
+      assert Zeit.parse("2025-01-15") == ~N[2025-01-15 00:00:00]
+    end
+
+    test "parse date-only string at year boundary" do
+      assert Zeit.parse("2024-12-31") == ~N[2024-12-31 00:00:00]
+      assert Zeit.parse("2025-01-01") == ~N[2025-01-01 00:00:00]
+    end
+
+    test "parse invalid date raises ArgumentError" do
+      assert_raise ArgumentError, ~r/Invalid date\/time format/, fn ->
+        Zeit.parse("not-a-date")
+      end
+    end
+
+    test "parse invalid date with wrong month raises ArgumentError" do
+      assert_raise ArgumentError, ~r/Invalid date\/time format/, fn ->
+        Zeit.parse("2025-13-01")
+      end
+    end
   end
 
   describe "jetzt/0" do

lib/zeitperiode_test.exs

@@ -378,6 +378,31 @@ defmodule Shared.ZeitperiodeTest do
       assert Periode.parse("2019-04-16T23:30:00+02:00--2019-04-16T23:45:00+02:00")
              |> entspricht_intervall?("2019-04-16T23:30:00+02:00/2019-04-16T23:45:00+02:00")
     end
+
+    test "parse date-only interval with slash separator" do
+      assert [start: ~N[2025-01-01 00:00:00], ende: ~N[2025-01-02 00:00:00]] =
+               Periode.parse("2025-01-01/2025-01-02")
+    end
+
+    test "parse date-only interval with double-dash separator" do
+      assert [start: ~N[2025-01-01 00:00:00], ende: ~N[2025-01-02 00:00:00]] =
+               Periode.parse("2025-01-01--2025-01-02")
+    end
+
+    test "parse date-only interval spanning months" do
+      assert [start: ~N[2025-01-15 00:00:00], ende: ~N[2025-02-15 00:00:00]] =
+               Periode.parse("2025-01-15/2025-02-15")
+    end
+
+    test "parse date-only interval spanning years" do
+      assert [start: ~N[2024-12-31 00:00:00], ende: ~N[2025-01-01 00:00:00]] =
+               Periode.parse("2024-12-31/2025-01-01")
+    end
+
+    test "parse single day interval" do
+      assert [start: ~N[2025-03-15 00:00:00], ende: ~N[2025-03-15 00:00:00]] =
+               Periode.parse("2025-03-15/2025-03-15")
+    end
   end
 
   describe "to_iso8601/1" do