test(e2e): mock the dashboard snapshot endpoint for tile specs

The v1.7.2 default-ON snapshot flag makes the dashboard read every tile
from GET /api/dashboard/snapshot; the e2e build sets no opt-out var, so
the specs that only mocked the legacy cells hit the real route, got
empty summaries for the zero-measurement seed user, and timed out the
tile/chart assertions.

Add a shared, correctly-typed mock helper and wire it into the five
tile-asserting specs alongside the existing legacy mocks (kept to
protect the reversible path).

e2e/chart-overlay-controls.spec.ts

@@ -1,6 +1,10 @@
 import { expect, test } from "@playwright/test";
 
 import { STORAGE_STATE_PATH } from "./setup/global-setup";
+import {
+  mockDashboardSnapshot,
+  WEIGHT_ONLY_SUMMARIES,
+} from "./utils/mock-dashboard-snapshot";
 
 /**
  * v1.4.18 — per-chart overlay-controls popover.
@@ -19,6 +23,11 @@ test.describe("chart overlay controls", () => {
   test.use({ storageState: STORAGE_STATE_PATH });
 
   test.beforeEach(async ({ page }) => {
+    // v1.7.2 — snapshot flag default-ON; mock the snapshot cell with a
+    // WEIGHT-only populated summary so the weight chart card paints.
+    // Legacy mocks below stay for the reversible `=false` path.
+    await mockDashboardSnapshot(page, { summaries: WEIGHT_ONLY_SUMMARIES });
+
     // Mock analytics + measurements so the dashboard paints at least
     // one chart card. Same seed shape the dashboard.spec.ts uses.
     //

e2e/charts-mobile.spec.ts

@@ -1,6 +1,7 @@
 import { expect, test } from "@playwright/test";
 
 import { STORAGE_STATE_PATH } from "./setup/global-setup";
+import { mockDashboardSnapshot } from "./utils/mock-dashboard-snapshot";
 
 /**
  * v1.4.19 A2 — mobile-viewport regression spec for chart cards.
@@ -31,6 +32,11 @@ test.describe("charts — mobile-viewport regression", () => {
   test.beforeEach(async ({ page }, testInfo) => {
     test.skip(testInfo.project.name !== "chromium-mobile", "mobile-only spec");
 
+    // v1.7.2 — snapshot flag default-ON; mock the snapshot cell with the
+    // same populated four-metric set so the charts paint. Legacy mocks
+    // below stay for the reversible `=false` path.
+    await mockDashboardSnapshot(page);
+
     // Mock analytics + measurements so the chart wrappers all clear
     // their data-floor gates. Same pattern as `dashboard.spec.ts`.
     //

e2e/dashboard.spec.ts

@@ -1,6 +1,7 @@
 import { expect, test } from "@playwright/test";
 
 import { STORAGE_STATE_PATH } from "./setup/global-setup";
+import { mockDashboardSnapshot } from "./utils/mock-dashboard-snapshot";
 
 /**
  * Authenticated dashboard render — proves the seed user can reach the
@@ -20,6 +21,14 @@ test.describe("authenticated dashboard render", () => {
   test.use({ storageState: STORAGE_STATE_PATH });
 
   test.beforeEach(async ({ page }) => {
+    // v1.7.2 — the dashboard snapshot flag is default-ON, so the page
+    // reads every tile from `/api/dashboard/snapshot` and ignores the
+    // legacy cells below. Mock the snapshot with the same populated
+    // four-metric set so the tile strip + charts paint. The legacy
+    // `/api/analytics` + `/api/mood/analytics` mocks stay for the
+    // reversible `NEXT_PUBLIC_DASHBOARD_SNAPSHOT=false` path.
+    await mockDashboardSnapshot(page);
+
     // Mock analytics with a populated weight summary so the weight tile
     // and chart render. `count` must be >0 for the tile to clear the
     // data-floor gate in `src/app/page.tsx`.

e2e/mobile-viewport.spec.ts

@@ -1,6 +1,10 @@
 import { expect, test } from "@playwright/test";
 
 import { STORAGE_STATE_PATH } from "./setup/global-setup";
+import {
+  mockDashboardSnapshot,
+  WEIGHT_ONLY_SUMMARIES,
+} from "./utils/mock-dashboard-snapshot";
 
 /**
  * Mobile-viewport smoke (Pixel 5 profile only). Asserts:
@@ -31,6 +35,11 @@ test.describe("mobile-viewport smoke", () => {
   test("dashboard has no horizontal scroll, bottom-nav respects content, all CTAs ≥ 44 px tall", async ({
     page,
   }) => {
+    // v1.7.2 — snapshot flag default-ON; mock the snapshot cell with a
+    // WEIGHT-only populated summary so the weight tile paints. Legacy
+    // mocks below stay for the reversible `=false` path.
+    await mockDashboardSnapshot(page, { summaries: WEIGHT_ONLY_SUMMARIES });
+
     // v1.4.37 W-CI — match `/api/analytics` AND any sliced variant
     // (`?slice=summaries`). The previous string glob `**/api/analytics`
     // didn't match the query-string form so the IW1 slim-slice fetch

e2e/onboarding-flicker.spec.ts

@@ -1,6 +1,10 @@
 import { expect, test } from "@playwright/test";
 
 import { STORAGE_STATE_PATH } from "./setup/global-setup";
+import {
+  mockDashboardSnapshot,
+  WEIGHT_ONLY_SUMMARIES,
+} from "./utils/mock-dashboard-snapshot";
 
 /**
  * v1.4.15 phase-A3 fix #3 — onboarding card flicker on dashboard load.
@@ -102,6 +106,17 @@ test.describe("dashboard onboarding card flicker guard", () => {
         }),
       }),
     );
+    // v1.7.2 — snapshot flag default-ON. The dashboard tile strip reads
+    // the snapshot cell; mock it with the populated WEIGHT summary
+    // (count 30 >= the 5-reading setup gate) and the same ~250 ms delay
+    // so the page's snapshot-driven tiles resolve on the same race
+    // window as the slowed analytics query the checklist reads. (The
+    // `GettingStartedChecklist` itself reads `/api/analytics?slice=...`
+    // unconditionally, so its flicker gate is unchanged.)
+    await mockDashboardSnapshot(page, {
+      summaries: WEIGHT_ONLY_SUMMARIES,
+      delayMs: 250,
+    });
     // Same `/api/dashboard/widgets` stub as the incomplete-onboarding
     // test below — keeps the dashboard from error-boundary-bailing
     // when this query 500s in CI without a real session.
@@ -192,6 +207,10 @@ test.describe("dashboard onboarding card flicker guard", () => {
         }),
       }),
     );
+    // v1.7.2 — snapshot flag default-ON. Empty snapshot summaries keep
+    // the tile strip blank (the user is still in setup) so the page
+    // renders the onboarding card path deterministically.
+    await mockDashboardSnapshot(page, { summaries: {} });
     await page.route("**/api/mood/analytics", (route) =>
       route.fulfill({
         status: 200,

e2e/utils/mock-dashboard-snapshot.ts

@@ -0,0 +1,172 @@
+import type { Page } from "@playwright/test";
+
+import {
+  DASHBOARD_WIDGET_CATALOGUE_IDS,
+  DEFAULT_DASHBOARD_LAYOUT,
+} from "@/lib/dashboard-layout";
+import type { DataSummary } from "@/lib/analytics/trends";
+import type {
+  DashboardSnapshot,
+  DashboardLayoutCatalogueEntry,
+} from "@/lib/dashboard/snapshot";
+
+/**
+ * v1.7.2 — shared mock for `GET /api/dashboard/snapshot`.
+ *
+ * The dashboard snapshot flag flipped default-ON in v1.7.2, so
+ * `src/app/page.tsx` reads every above-the-fold tile from the single
+ * `/api/dashboard/snapshot` cell unless `NEXT_PUBLIC_DASHBOARD_SNAPSHOT`
+ * is `"false"`. The e2e build sets no such var, so the snapshot path is
+ * live in CI. Specs that previously mocked only the legacy cells
+ * (`/api/analytics` + `/api/mood/analytics` + `/api/dashboard/widgets`)
+ * now hit the REAL snapshot route, which returns empty `summaries` for
+ * the seed user (zero measurements) and blanks the tile strip.
+ *
+ * `mockDashboardSnapshot` registers a `page.route` for the snapshot
+ * endpoint returning a correctly-typed `DashboardSnapshot` so the
+ * default-ON path paints deterministic tiles. Callers keep their legacy
+ * mocks alongside it — harmless, and they protect the reversible
+ * `NEXT_PUBLIC_DASHBOARD_SNAPSHOT=false` path.
+ */
+
+/** Fill a `DataSummary` from a sparse partial, defaulting the rest. */
+function summary(partial: Partial<DataSummary>): DataSummary {
+  return {
+    count: 0,
+    latest: null,
+    min: null,
+    max: null,
+    mean: null,
+    avg7: null,
+    avg30: null,
+    slope7: null,
+    slope30: null,
+    slope90: null,
+    anomalyCount: 0,
+    avg30LastMonth: null,
+    avg30LastYear: null,
+    ...partial,
+  };
+}
+
+/**
+ * Four-metric populated tile set mirroring the legacy `/api/analytics`
+ * mock shared by `dashboard.spec.ts` / `charts-mobile.spec.ts` /
+ * `chart-overlay-controls.spec.ts`. Every summary has `count > 0` so the
+ * tile clears the data-floor gate in `src/app/page.tsx`.
+ */
+export const POPULATED_SUMMARIES: Record<string, DataSummary> = {
+  WEIGHT: summary({
+    latest: 78.5,
+    avg7: 78.2,
+    avg30: 77.9,
+    slope30: { slope: -0.05, direction: "down", confidence: 0.8 },
+    count: 30,
+  }),
+  BLOOD_PRESSURE_SYS: summary({
+    latest: 124,
+    avg7: 122,
+    avg30: 121,
+    slope30: { slope: 0.1, direction: "stable", confidence: 0.3 },
+    count: 30,
+  }),
+  BLOOD_PRESSURE_DIA: summary({
+    latest: 80,
+    avg7: 79,
+    avg30: 78,
+    slope30: { slope: 0.05, direction: "stable", confidence: 0.2 },
+    count: 30,
+  }),
+  PULSE: summary({
+    latest: 68,
+    avg7: 70,
+    avg30: 71,
+    slope30: { slope: -0.2, direction: "down", confidence: 0.6 },
+    count: 30,
+  }),
+};
+
+/** WEIGHT-only populated set for specs that only need one tile + chart. */
+export const WEIGHT_ONLY_SUMMARIES: Record<string, DataSummary> = {
+  WEIGHT: POPULATED_SUMMARIES.WEIGHT,
+};
+
+function buildLayoutCatalogue(): DashboardLayoutCatalogueEntry[] {
+  return DASHBOARD_WIDGET_CATALOGUE_IDS.map((id, order) => ({
+    id,
+    visible: true,
+    order,
+  }));
+}
+
+export interface MockSnapshotOptions {
+  /**
+   * Tile summaries keyed by `MeasurementType`. Defaults to the
+   * four-metric populated set. Pass `{}` for an empty strip (e.g. the
+   * incomplete-onboarding branch).
+   */
+  summaries?: Record<string, DataSummary>;
+  /** Artificial latency in ms before the route fulfils (race specs). */
+  delayMs?: number;
+}
+
+/** Assemble a fully-typed snapshot body from the requested tile data. */
+export function buildMockSnapshot(
+  options: MockSnapshotOptions = {},
+): DashboardSnapshot {
+  const summaries = options.summaries ?? POPULATED_SUMMARIES;
+  const now = new Date().toISOString();
+  const lastSeenByType: Record<
+    string,
+    { lastSeenAt: string; daysAgo: number } | null
+  > = {};
+  for (const type of Object.keys(summaries)) {
+    lastSeenByType[type] = { lastSeenAt: now, daysAgo: 0 };
+  }
+  return {
+    user: {
+      username: "e2e-tester",
+      timezone: "Europe/Berlin",
+      heightCm: 180,
+      dateOfBirth: "1990-01-01T00:00:00.000Z",
+      gender: "MALE",
+      glucoseUnit: "mg/dL",
+      onboardingTourCompleted: true,
+      greetingHour: 9,
+    },
+    layout: DEFAULT_DASHBOARD_LAYOUT,
+    layoutCatalogue: buildLayoutCatalogue(),
+    metricStates: {},
+    tiles: {
+      summaries,
+      lastSeenByType,
+      mood: { summary: null, entries: [] },
+    },
+    extras: null,
+    briefing: null,
+    briefingState: "preparing",
+    briefingUpdatedAt: null,
+    generatedAt: now,
+  };
+}
+
+/**
+ * Register a `page.route` interceptor for `GET /api/dashboard/snapshot`
+ * returning the API envelope `{ data: DashboardSnapshot, error: null }`.
+ */
+export async function mockDashboardSnapshot(
+  page: Page,
+  options: MockSnapshotOptions = {},
+): Promise<void> {
+  const body = buildMockSnapshot(options);
+  await page.route(/\/api\/dashboard\/snapshot(\?|$)/, async (route) => {
+    if (options.delayMs) {
+      await new Promise((resolve) => setTimeout(resolve, options.delayMs));
+    }
+    await route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ data: body, error: null }),
+    });
+  });
+}