Add post and event cards, shared calendar sheet and per-event ICS; rework past events and next-event card

Elternbeirat.Web.Tests/EventDateFormatTests.cs

@@ -0,0 +1,105 @@
+using Elternbeirat.Contracts;
+using Elternbeirat.Web.Features.Events;
+
+namespace Elternbeirat.Web.Tests;
+
+/// <summary>
+/// Unit tests for the calendar sheet texts and the time line beside it. Pure logic,
+/// no PocketBase needed. All times are Berlin wall-clock, as the contract delivers them.
+/// </summary>
+public class EventDateFormatTests
+{
+    private static Event Event(DateTime start, DateTime? end = null) =>
+        new() { Id = "test", Title = "Termin", Start = start, End = end };
+
+    [Theory]
+    [InlineData(1, "Jan")]
+    [InlineData(3, "März")]
+    [InlineData(5, "Mai")]
+    [InlineData(10, "Okt")]
+    [InlineData(12, "Dez")]
+    public void Sheet_month_is_the_German_short_month_without_period(int month, string expected) =>
+        EventDateFormat.SheetMonth(new DateTime(2026, month, 1)).ShouldBe(expected);
+
+    [Fact]
+    public void Sheet_day_has_no_leading_zero() =>
+        EventDateFormat.SheetDay(new DateTime(2026, 10, 8, 19, 30, 0)).ShouldBe("8");
+
+    [Theory]
+    [InlineData(8, "Do")]  // Thursday, 8 October 2026
+    [InlineData(11, "So")] // Sunday
+    public void Sheet_weekday_is_the_German_short_weekday_without_period(int day, string expected) =>
+        EventDateFormat.SheetWeekday(new DateTime(2026, 10, day)).ShouldBe(expected);
+
+    [Fact]
+    public void Past_all_day_event_shows_the_day_and_no_time()
+    {
+        var allDay = Event(new DateTime(2026, 11, 13));
+
+        EventDateFormat.PastDays(allDay).ShouldBe("13. November");
+        EventDateFormat.PastTime(allDay).ShouldBe("");
+    }
+
+    [Fact]
+    public void Past_timed_event_shows_the_day_and_its_start_time()
+    {
+        var timed = Event(new DateTime(2026, 9, 1, 19, 0, 0));
+
+        EventDateFormat.PastDays(timed).ShouldBe("1. September"); // no leading zero
+        EventDateFormat.PastTime(timed).ShouldBe("19:00 Uhr");
+    }
+
+    [Fact]
+    public void Past_timed_event_ending_the_same_day_shows_the_time_range()
+    {
+        var evening = Event(new DateTime(2026, 11, 13, 19, 0, 0), new DateTime(2026, 11, 13, 21, 0, 0));
+
+        EventDateFormat.PastDays(evening).ShouldBe("13. November");
+        EventDateFormat.PastTime(evening).ShouldBe("19:00–21:00 Uhr");
+    }
+
+    [Fact]
+    public void Past_multi_day_event_in_one_month_names_the_month_once() =>
+        EventDateFormat.PastDays(Event(new DateTime(2026, 2, 8), new DateTime(2026, 2, 9))).ShouldBe("8.–9. Februar");
+
+    [Fact]
+    public void Past_multi_day_event_across_a_month_names_both_months() =>
+        EventDateFormat.PastDays(Event(new DateTime(2026, 1, 30), new DateTime(2026, 2, 2)))
+            .ShouldBe("30. Januar – 2. Februar");
+
+    [Fact]
+    public void Past_multi_day_event_across_a_year_names_the_end_year() =>
+        // The list is grouped by the start year, so only the end needs its year.
+        EventDateFormat.PastDays(Event(new DateTime(2026, 12, 30), new DateTime(2027, 1, 2)))
+            .ShouldBe("30. Dezember – 2. Januar 2027");
+
+    [Fact]
+    public void Past_timed_multi_day_event_shows_only_the_start_time() =>
+        // A range here would read as the daily hours.
+        EventDateFormat.PastTime(Event(new DateTime(2026, 2, 8, 9, 0, 0), new DateTime(2026, 2, 9, 13, 0, 0)))
+            .ShouldBe("09:00 Uhr");
+
+    [Fact]
+    public void Span_of_a_timed_event_without_end_is_its_start_time() =>
+        EventDateFormat.Span(Event(new DateTime(2026, 10, 8, 19, 30, 0))).ShouldBe("19:30 Uhr");
+
+    [Fact]
+    public void Span_of_a_same_day_event_is_the_time_range() =>
+        EventDateFormat.Span(Event(new DateTime(2026, 10, 8, 19, 30, 0), new DateTime(2026, 10, 8, 21, 0, 0)))
+            .ShouldBe("19:30–21:00 Uhr");
+
+    [Fact]
+    public void Span_of_a_multi_day_event_names_the_last_day() =>
+        EventDateFormat.Span(Event(new DateTime(2026, 10, 9, 9, 0, 0), new DateTime(2026, 10, 11, 13, 0, 0)))
+            .ShouldBe("09:00 Uhr bis Sonntag, 11. Oktober 2026, 13:00 Uhr");
+
+    [Fact]
+    public void Span_of_a_multi_day_all_day_event_has_no_times() =>
+        EventDateFormat.Span(Event(new DateTime(2026, 10, 9), new DateTime(2026, 10, 11)))
+            .ShouldBe("bis Sonntag, 11. Oktober 2026");
+
+    [Fact]
+    public void Span_of_a_single_all_day_event_is_empty() =>
+        // The sheet already shows the day; there is nothing left to say.
+        EventDateFormat.Span(Event(new DateTime(2026, 10, 8))).ShouldBe("");
+}