feat: tweak calendar and clean it up

src/seqta/utils/googleCalendar/syncDateRange.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it } from "@jest/globals";
+import {
+  droppedWeekRange,
+  syncWindowRange,
+  trailingWeekRange,
+} from "./syncDateRange";
+
+describe("syncDateRange", () => {
+  it("builds a 12-week rolling window from the current week", () => {
+    const range = syncWindowRange(12);
+    expect(range.from <= range.until).toBe(true);
+
+    const start = new Date(`${range.from}T12:00:00`);
+    const end = new Date(`${range.until}T12:00:00`);
+    const days = Math.round((end.getTime() - start.getTime()) / 86_400_000) + 1;
+    expect(days).toBe(12 * 7);
+  });
+
+  it("places the trailing week at the end of the window", () => {
+    const window = syncWindowRange(12);
+    const trailing = trailingWeekRange(12);
+    expect(trailing.from >= window.from).toBe(true);
+    expect(trailing.until <= window.until).toBe(true);
+  });
+
+  it("places the dropped week before the window start", () => {
+    const window = syncWindowRange(12);
+    const dropped = droppedWeekRange(12);
+    expect(dropped.until < window.from).toBe(true);
+  });
+});