fix(calendar): preserve chronological placement with Bases sorting

docs/releases/unreleased.md

@@ -16,6 +16,8 @@ Example:
 ```
 ## Fixed
 
+- Keep agenda events chronological when a Base sort is configured; use Base order at the same calendar time. Follow-up to #1411, reported by @ky1ejs.
+
 - (#768) Fixed calendar view appearing empty in week and day views due to invalid time configuration values
   - Added time validation in settings UI with proper error messages and debouncing
   - Prevents "Cannot read properties of null (reading 'years')" error from FullCalendar

src/bases/CalendarView.ts

@@ -179,7 +179,9 @@ export function getTaskNotesCalendarEventOrder(sortConfig: unknown): string {
 	if (!hasBasesCalendarSortConfig(sortConfig)) {
 		return DEFAULT_CALENDAR_EVENT_ORDER;
 	}
-	return `${TASKNOTES_CALENDAR_SORT_INDEX},${DEFAULT_CALENDAR_EVENT_ORDER}`;
+	// Bases ranks break ties at the same placement. They must not put a timed
+	// task ahead of an earlier appointment that has no Bases result index.
+	return `start,allDay,${TASKNOTES_CALENDAR_SORT_INDEX},-duration,title`;
 }
 
 function getCalendarEventSortPath(event: EventInput): string | null {

tests/unit/issues/issue-1411-agenda-bases-sort.test.ts

@@ -1,4 +1,5 @@
 import type { EventInput } from "@fullcalendar/core";
+import { execFileSync } from "node:child_process";
 import {
 	applyBasesSortIndexesToCalendarEvents,
 	getTaskNotesCalendarEventOrder,
@@ -13,15 +14,46 @@ describe("Issue #1411: Agenda Calendar Bases respect Bases sort order", () => {
 		expect(getTaskNotesCalendarEventOrder(undefined)).toBe("start,-duration,allDay,title");
 	});
 
-	it("puts the TaskNotes sort index first when the Base has a sort config", () => {
+	it("uses Bases order after event time, before duration and title", () => {
 		const sortConfig = [{ column: "note.status", direction: "ASC" }];
 
 		expect(hasBasesCalendarSortConfig(sortConfig)).toBe(true);
 		expect(getTaskNotesCalendarEventOrder(sortConfig)).toBe(
-			`${TASKNOTES_CALENDAR_SORT_INDEX},start,-duration,allDay,title`
+			`start,allDay,${TASKNOTES_CALENDAR_SORT_INDEX},-duration,title`
 		);
 	});
 
+	it("interleaves timed tasks with appointments while sorting untimed tasks by Bases rank", () => {
+		const order = getTaskNotesCalendarEventOrder([{ column: "status" }]);
+		const events = [
+			{ title: "Evening task", start: 20, tasknotesSortIndex: 0 },
+			{ title: "Morning appointment", start: 9 },
+			{ title: "Morning task", start: 8, tasknotesSortIndex: 3 },
+			{ title: "Ready", start: 0, tasknotesSortIndex: 2 },
+			{ title: "Doing", start: 0, tasknotesSortIndex: 1 },
+		];
+		// The suite mocks FullCalendar. Exercise its real comparator in Node.
+		const sorted = JSON.parse(
+			execFileSync(
+				process.execPath,
+				[
+					"-e",
+					"const {parseFieldSpecs,compareByFieldSpecs}=require('@fullcalendar/core/internal'); const events=JSON.parse(process.argv[2]); const specs=parseFieldSpecs(process.argv[1]); console.log(JSON.stringify(events.sort((a,b)=>compareByFieldSpecs(a,b,specs)).map(e=>e.title)));",
+					order,
+					JSON.stringify(events),
+				],
+				{ encoding: "utf8" }
+			)
+		);
+		expect(sorted).toEqual([
+			"Doing",
+			"Ready",
+			"Morning task",
+			"Morning appointment",
+			"Evening task",
+		]);
+	});
+
 	it("adds Bases result indexes to task and property-based events", () => {
 		const events: EventInput[] = [
 			{