test: 更新单元测试

Author: ArgoZhang

test/UnitTest/Components/DateTimePickerTest.cs

@@ -959,6 +959,20 @@ public void SidebarTemplate_Ok()
         cut.Contains("test-sidebar-template");
     }
 
+    [Fact]
+    public void FirstDayOfWeek_Ok()
+    {
+        var cut = Context.RenderComponent<DateTimePicker<DateTime>>(pb =>
+        {
+            pb.Add(a => a.FirstDayOfWeek, DayOfWeek.Monday);
+            pb.Add(a => a.Value, new DateTime(2025, 02, 20));
+        });
+
+        var labels = cut.FindAll(".date-table tbody > tr:first-child > th");
+        Assert.Equal("一", labels[0].TextContent);
+        Assert.Equal("日", labels[6].TextContent);
+    }
+
     [Fact]
     public void GetSafeYearDateTime_Ok()
     {