fix(SW-3442) getLowestRoomPrice - cannot read property of undefined

* fix: getLowestRoomPrice throws when given unexpected data
* dont track lowestRoomPrice if unavailable


Approved-by: Hrishikesh Vaipurkar

packages/booking-flow/lib/contexts/SelectRate/SelectRateContext/calculateNumberOfNights.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from "vitest"
+
+import { calculateNumberOfNights } from "./calculateNumberOfNights"
+
+describe("calculateNumberOfNights", () => {
+  it("returns 0 when fromDate is undefined", () => {
+    expect(calculateNumberOfNights(undefined, "2023-01-02")).toBe(0)
+  })
+
+  it("returns 0 when toDate is undefined", () => {
+    expect(calculateNumberOfNights("2023-01-01", undefined)).toBe(0)
+  })
+
+  it("returns 0 for the same date (string)", () => {
+    expect(calculateNumberOfNights("2023-01-01", "2023-01-01")).toBe(0)
+  })
+
+  it("calculates nights for string date inputs", () => {
+    expect(calculateNumberOfNights("2023-01-01", "2023-01-05")).toBe(4)
+  })
+
+  it("calculates nights for Date object inputs", () => {
+    expect(
+      calculateNumberOfNights(
+        new Date("2023-02-10T00:00:00Z"),
+        new Date("2023-02-12T00:00:00Z")
+      )
+    ).toBe(2)
+  })
+
+  it("handles mixed Date and string inputs", () => {
+    expect(calculateNumberOfNights(new Date("2023-03-01"), "2023-03-04")).toBe(
+      3
+    )
+  })
+
+  it("returns a negative number when fromDate is after toDate", () => {
+    expect(calculateNumberOfNights("2023-01-05", "2023-01-01")).toBe(-4)
+  })
+})