fix(GRO-2180): portal Appointments handles ISO startTime shape

The /api/portal/appointments contract returns ISO `startTime`/`endTime`
and no `date`/`time` fields. `isUpcoming()` read `appt.date`/`appt.time`
and called `parseTimeTo24Hour(undefined)` → `undefined.split(' ')` →
TypeError. The throw was swallowed by the fetch `try/catch`, surfacing
"Failed to load appointments" and making "Book New" unreachable for
every signed-in customer.

- Add `getAppointmentStart()` helper: prefers ISO `startTime`, falls
  back to legacy `date` + `time`, returns null on missing/unparseable
  input so callers never throw.
- Rewrite `isUpcoming()` on top of the helper.
- Add `formatAppointmentDate()` / `formatAppointmentTime()` and use them
  at all date/time display sites (list row + RescheduleFlow header).
- Guard `parseTimeTo24Hour(undefined)`.
- Mark `date`/`time` optional and add `startTime`/`endTime` to the
  `Appointment` type to match the API contract.
- Tests: API-shape fixtures + regression guards (no throw on startTime
  shape, undefined-safe parse, helper resolution/formatting).
- Update UAT_PLAYBOOK.md §5.12 (customer portal appointments).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

UAT_PLAYBOOK.md

@@ -182,9 +182,13 @@ export const { signIn, signOut, useSession, changePassword } = authClient;
 | # | Scenario | Steps | Expected |
 |---|----------|-------|----------|
 | TC-WEB-5.12.1 | Client-facing view | Log in as client persona | Customer portal UI displayed |
-| TC-WEB-5.12.2 | Appointment list | View client portal appointments | List of client's appointments visible |
+| TC-WEB-5.12.2 | Appointment list loads | Sign in as `uat-customer@groombook.dev`, open **Appointments** | List of the customer's appointments renders. **No** "Failed to load appointments" error and **no** Retry button. (GRO-2180) |
-| TC-WEB-5.12.3 | Confirm appointment | Click confirm on pending appointment | Appointment status updated to confirmed |
+| TC-WEB-5.12.3 | Date/time display | Inspect each appointment card | Each card shows a human-readable date and time derived from the API `startTime` (e.g. "Mon, Jun 1, 2026" / "10:00 AM"); no `undefined` or blank date/time. (GRO-2180) |
-| TC-WEB-5.12.4 | Cancel appointment | Click cancel on appointment | Appointment marked as cancelled |
+| TC-WEB-5.12.4 | Book New reachable | On the loaded Appointments view (non-readonly), look for the **Book New** button | "Book New" button is visible and opens the booking modal. (GRO-2180) |
+| TC-WEB-5.12.5 | Upcoming/Past split | Toggle the **Upcoming** and **Past** tabs | Future appointments appear under Upcoming; completed/cancelled/past appear under Past. (GRO-2180) |
+| TC-WEB-5.12.6 | Confirm appointment | Click confirm on pending appointment | Appointment status updated to confirmed |
+| TC-WEB-5.12.7 | Cancel appointment | Click cancel on appointment | Appointment marked as cancelled |
+| TC-WEB-5.12.8 | Reschedule display | Open **Reschedule** on an upcoming appointment | Summary header shows the current appointment's date and time (from `startTime`); no `undefined`. (GRO-2180) |
 
 #### 5.12b Dynamic Portal Time Slots (GRO-1793, GRO-2105)
 

src/__tests__/Appointments.test.tsx

@@ -1,6 +1,6 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
 import { render, screen, fireEvent, waitFor } from "@testing-library/react";
-import { parseTimeTo24Hour, isUpcoming, CustomerNotesSection, ConfirmationSection, StatusBadge } from "../portal/sections/Appointments.tsx";
+import { parseTimeTo24Hour, isUpcoming, getAppointmentStart, formatAppointmentDate, formatAppointmentTime, CustomerNotesSection, ConfirmationSection, StatusBadge } from "../portal/sections/Appointments.tsx";
 
 const UPCOMING_APPT = {
   id: "appt-1",
@@ -29,6 +29,26 @@ const PAST_APPT = {
   status: "completed" as const,
 };
 
+// GRO-2180: the /api/portal/appointments contract returns ISO startTime/endTime
+// and no date/time fields. These fixtures mirror that shape exactly.
+const API_UPCOMING_APPT = {
+  id: "appt-api-1",
+  petId: "pet-1",
+  serviceId: "service-1",
+  groomerId: null,
+  startTime: "2099-01-01T10:00:00.000Z",
+  endTime: "2099-01-01T10:45:00.000Z",
+  status: "confirmed" as const,
+};
+
+const API_PAST_APPT = {
+  ...API_UPCOMING_APPT,
+  id: "appt-api-2",
+  startTime: "2020-01-01T10:00:00.000Z",
+  endTime: "2020-01-01T10:45:00.000Z",
+  status: "completed" as const,
+};
+
 describe("parseTimeTo24Hour", () => {
   it("converts AM times correctly", () => {
     expect(parseTimeTo24Hour("9:00 AM")).toBe("09:00:00");
@@ -42,6 +62,13 @@ describe("parseTimeTo24Hour", () => {
     expect(parseTimeTo24Hour("11:00 PM")).toBe("23:00:00");
     expect(parseTimeTo24Hour("12:00 PM")).toBe("12:00:00");
   });
+
+  // GRO-2180 regression: must not throw on undefined/empty input.
+  it("returns a safe default for missing input", () => {
+    expect(() => parseTimeTo24Hour(undefined)).not.toThrow();
+    expect(parseTimeTo24Hour(undefined)).toBe("00:00:00");
+    expect(parseTimeTo24Hour("")).toBe("00:00:00");
+  });
 });
 
 describe("isUpcoming", () => {
@@ -60,6 +87,63 @@ describe("isUpcoming", () => {
   it("returns false for completed appointments", () => {
     expect(isUpcoming({ ...UPCOMING_APPT, status: "completed" })).toBe(false);
   });
+
+  // GRO-2180 regression: the API contract uses ISO startTime with no date/time.
+  // Previously isUpcoming threw a TypeError on this shape, breaking the page.
+  it("does not throw on the API startTime/endTime shape", () => {
+    expect(() => isUpcoming(API_UPCOMING_APPT)).not.toThrow();
+    expect(() => isUpcoming(API_PAST_APPT)).not.toThrow();
+  });
+
+  it("returns true for future appointments using startTime", () => {
+    expect(isUpcoming(API_UPCOMING_APPT)).toBe(true);
+  });
+
+  it("returns false for past appointments using startTime", () => {
+    expect(isUpcoming(API_PAST_APPT)).toBe(false);
+  });
+
+  it("returns false (not throw) when neither startTime nor date is present", () => {
+    const { startTime, endTime, ...noDate } = API_UPCOMING_APPT;
+    void startTime;
+    void endTime;
+    expect(() => isUpcoming(noDate)).not.toThrow();
+    expect(isUpcoming(noDate)).toBe(false);
+  });
+});
+
+describe("getAppointmentStart / display helpers (GRO-2180)", () => {
+  it("resolves the start instant from ISO startTime", () => {
+    const start = getAppointmentStart(API_UPCOMING_APPT);
+    expect(start).not.toBeNull();
+    expect(start?.toISOString()).toBe("2099-01-01T10:00:00.000Z");
+  });
+
+  it("falls back to legacy date + time when startTime is absent", () => {
+    const start = getAppointmentStart(UPCOMING_APPT);
+    expect(start).not.toBeNull();
+  });
+
+  it("returns null when there is no usable date", () => {
+    const { startTime, endTime, ...noDate } = API_UPCOMING_APPT;
+    void startTime;
+    void endTime;
+    expect(getAppointmentStart(noDate)).toBeNull();
+  });
+
+  it("formats date/time without throwing on the API shape", () => {
+    expect(() => formatAppointmentDate(API_UPCOMING_APPT)).not.toThrow();
+    expect(() => formatAppointmentTime(API_UPCOMING_APPT)).not.toThrow();
+    expect(formatAppointmentDate(API_UPCOMING_APPT)).not.toBe("");
+    expect(formatAppointmentTime(API_UPCOMING_APPT)).not.toBe("");
+  });
+
+  it("returns empty display strings when there is no usable date", () => {
+    const { startTime, endTime, ...noDate } = API_UPCOMING_APPT;
+    void startTime;
+    void endTime;
+    expect(formatAppointmentDate(noDate)).toBe("");
+  });
 });
 
 describe("CustomerNotesSection", () => {

src/portal/sections/Appointments.tsx

@@ -36,8 +36,14 @@ export interface Appointment {
   petId: string;
   serviceId: string;
   groomerId: string | null;
-  date: string;
+  // The /api/portal/appointments contract returns ISO `startTime`/`endTime`.
-  time: string;
+  // `date`/`time` are the legacy display shape, still produced locally by some
+  // flows (e.g. test fixtures), so both shapes are optional and code reads
+  // `startTime` first, falling back to `date` + `time`.
+  startTime?: string;
+  endTime?: string;
+  date?: string;
+  time?: string;
   status: 'scheduled' | 'confirmed' | 'pending' | 'waitlisted' | 'completed' | 'cancelled' | 'no-show';
   petName?: string;
   serviceName?: string;
@@ -91,7 +97,8 @@ export function formatDate(dateStr: string): string {
   });
 }
 
-export function parseTimeTo24Hour(time: string): string {
+export function parseTimeTo24Hour(time: string | null | undefined): string {
+  if (!time) return '00:00:00';
   const parts = time.split(' ');
   const hoursMinutes = parts[0] ?? '';
   const period = parts[1] ?? '';
@@ -104,10 +111,41 @@ export function parseTimeTo24Hour(time: string): string {
   return `${hours24.toString().padStart(2, '0')}:${minutes.toString().padStart(2, '0')}:00`;
 }
 
+/**
+ * Resolve an appointment's start instant from either the API contract shape
+ * (ISO `startTime`) or the legacy `date` + `time` shape. Returns null when no
+ * usable date is present or the value is unparseable, so callers never throw.
+ */
+export function getAppointmentStart(appt: Appointment): Date | null {
+  const raw = appt.startTime
+    ? appt.startTime
+    : appt.date
+      ? `${appt.date}T${parseTimeTo24Hour(appt.time)}`
+      : null;
+  if (!raw) return null;
+  const parsed = new Date(raw);
+  return isNaN(parsed.getTime()) ? null : parsed;
+}
+
 export function isUpcoming(appt: Appointment): boolean {
-  const now = new Date();
+  const start = getAppointmentStart(appt);
-  const apptDate = new Date(`${appt.date}T${parseTimeTo24Hour(appt.time)}`);
+  if (!start) return false;
-  return apptDate > now && appt.status !== 'cancelled' && appt.status !== 'completed';
+  return start > new Date() && appt.status !== 'cancelled' && appt.status !== 'completed';
+}
+
+/** Display date string, preferring the ISO `startTime` contract shape. */
+export function formatAppointmentDate(appt: Appointment): string {
+  const start = getAppointmentStart(appt);
+  return start ? formatDate(start.toISOString()) : '';
+}
+
+/** Display time string, preferring the ISO `startTime` contract shape. */
+export function formatAppointmentTime(appt: Appointment): string {
+  const start = getAppointmentStart(appt);
+  if (start) {
+    return start.toLocaleTimeString('en-US', { hour: 'numeric', minute: '2-digit' });
+  }
+  return appt.time ?? '';
 }
 
 const STATUS_COLORS: Record<string, string> = {
@@ -338,11 +376,11 @@ function AppointmentCard({
           <div className="flex items-center gap-3 text-xs text-stone-500 mt-0.5">
             <span className="flex items-center gap-1">
               <Calendar size={12} />
-              {formatDate(appt.date)}
+              {formatAppointmentDate(appt)}
             </span>
             <span className="flex items-center gap-1">
               <Clock size={12} />
-              {appt.time}
+              {formatAppointmentTime(appt)}
             </span>
             <span>with {appt.groomerName || 'First Available'}</span>
           </div>
@@ -710,7 +748,7 @@ export function RescheduleFlow({
                   {appt.petName || 'Pet'} — {appt.serviceName || 'Service'}
                 </p>
                 <p className="text-stone-500 mt-0.5">
-                  {formatDate(appt.date)} at {appt.time} with{' '}
+                  {formatAppointmentDate(appt)} at {formatAppointmentTime(appt)} with{' '}
                   {appt.groomerName || 'First Available'}
                 </p>
               </div>