fix(domain): repair the red suite and the dead repository

src/domain/cart/policy/__spec__/ShippingPolicy.spec.ts

@@ -2,30 +2,33 @@ import { describe, expect, it } from "vitest";
 import { Money } from "@/domain/cart/value-objects/Money";
 import { ShippingPolicy } from "../ShippingPolicy";
 
+const threshold = ShippingPolicy.SHIPPING_THRESHOLD.toAmount();
+const cost = ShippingPolicy.SHIPPING_COST.toAmount();
+
 describe("ShippingPolicy", () => {
   it("should return 0 shipping if subtotal is equal to or above the threshold", () => {
-    const subtotalAtThreshold = new Money(50);
-    const subtotalAboveThreshold = new Money(100);
+    const subtotalAtThreshold = new Money(threshold);
+    const subtotalAboveThreshold = new Money(threshold + 100);
 
     expect(ShippingPolicy.calculate(subtotalAtThreshold).toAmount()).toBe(0);
     expect(ShippingPolicy.calculate(subtotalAboveThreshold).toAmount()).toBe(0);
   });
 
   it("should return the shipping cost if subtotal is below the threshold", () => {
-    const subtotalBelowThreshold = new Money(25);
+    const subtotalBelowThreshold = new Money(threshold - 100);
     const shippingCost = ShippingPolicy.calculate(subtotalBelowThreshold);
 
-    expect(shippingCost.toAmount()).toBe(5.99);
+    expect(shippingCost.toAmount()).toBe(cost);
   });
 
   it("should correctly handle edge case just below threshold", () => {
-    const subtotalJustBelow = new Money(49.99);
+    const subtotalJustBelow = new Money(threshold - 0.01);
     const shippingCost = ShippingPolicy.calculate(subtotalJustBelow);
-    expect(shippingCost.toAmount()).toBe(5.99);
+    expect(shippingCost.toAmount()).toBe(cost);
   });
 
   it("should correctly handle edge case just above threshold", () => {
-    const subtotalJustAbove = new Money(50.01);
+    const subtotalJustAbove = new Money(threshold + 0.01);
     const shippingCost = ShippingPolicy.calculate(subtotalJustAbove);
     expect(shippingCost.toAmount()).toBe(0);
   });

src/domain/cart/value-objects/Product/Product.ts

@@ -109,14 +109,10 @@ export class Product {
   }
 
   getLoreLink(level: KnowledgeProfile): string {
-    if (level === "beginner") return this._knowledge.getProfileLoreLink(level);
-    if (level === "adventurer") return this._knowledge.getProfileLoreLink(level);
     return this._knowledge.getProfileLoreLink(level);
   }
 
   getVideoUrl(level: KnowledgeProfile): string {
-    if (level === "beginner") return this._knowledge.getProfileVideoUrl(level);
-    if (level === "adventurer") return this._knowledge.getProfileVideoUrl(level);
     return this._knowledge.getProfileVideoUrl(level);
   }
 }

src/domain/cart/value-objects/Product/__spec__/Product.spec.ts

@@ -24,12 +24,27 @@ describe("Product Value Objects", () => {
 });
 
 describe("KnowledgeContent and Product", () => {
-  const stats = new Stats(10, 20, 5);
-  const effects = [new Effect("Fire damage")];
-  const extraResources = new ExtraResources("https://lore.link", "https://video.link");
-  const profile = new ProfileDetails("A legendary sword", stats, effects, extraResources);
+  const statsByLevel = {
+    beginner: { power: 1, durability: 2, manaBoost: 3 },
+    adventurer: { power: 4, durability: 5, manaBoost: 6 },
+    expert: { power: 7, durability: 8, manaBoost: 9 },
+  } as const;
 
-  const knowledge = new KnowledgeContent(profile, profile, profile);
+  const profileFor = (level: "beginner" | "adventurer" | "expert") => {
+    const { power, durability, manaBoost } = statsByLevel[level];
+    return new ProfileDetails(
+      `${level} tale`,
+      new Stats(power, durability, manaBoost),
+      [new Effect(`${level} effect`)],
+      new ExtraResources(`https://lore.link/${level}`, `https://video.link/${level}`),
+    );
+  };
+
+  const knowledge = new KnowledgeContent(
+    profileFor("beginner"),
+    profileFor("adventurer"),
+    profileFor("expert"),
+  );
 
   const product = new Product(
     new ProductId("sword01"),
@@ -46,23 +61,14 @@ describe("KnowledgeContent and Product", () => {
     expect(product.displayImage()).toBe("http://image.link");
   });
 
-  it("should return profile description, effects, stats, lore link, and video URL", () => {
-    const levels: ("beginner" | "adventurer" | "expert")[] = [
-      "beginner",
-      "adventurer",
-      "expert",
-    ];
-
-    for (const level of levels) {
-      expect(product.describeProfile(level)).toBe("A legendary sword");
-      expect(product.listProfileEffects(level)).toEqual(["Fire damage"]);
-      expect(product.getProfileStats(level)).toEqual({
-        power: 10,
-        durability: 20,
-        manaBoost: 5,
-      });
-      expect(product.getLoreLink(level)).toBe("https://lore.link");
-      expect(product.getVideoUrl(level)).toBe("https://video.link");
-    }
-  });
+  it.each(["beginner", "adventurer", "expert"] as const)(
+    "should route %s to its own profile's description, effects, stats, lore link, and video URL",
+    (level) => {
+      expect(product.describeProfile(level)).toBe(`${level} tale`);
+      expect(product.listProfileEffects(level)).toEqual([`${level} effect`]);
+      expect(product.getProfileStats(level)).toEqual(statsByLevel[level]);
+      expect(product.getLoreLink(level)).toBe(`https://lore.link/${level}`);
+      expect(product.getVideoUrl(level)).toBe(`https://video.link/${level}`);
+    },
+  );
 });

src/ui/components/WelcomeModal/WelcomeStorage/LocalStorageWelcomeSurvey.repository.ts

@@ -10,7 +10,7 @@ import {
 
 export class LocalStorageWelcomeSurveyRepository implements WelcomeStorageRepository {
   private listeners = new Set<Listener>();
-  private cache: WelcomeSurveyStoreState = { survey: null };
+  private cache: WelcomeSurveyStoreState | undefined;
 
   getSurvey = (): WelcomeSurveyStoreState["survey"] => {
     if (this.cache !== undefined) {

src/ui/components/WelcomeModal/WelcomeStorage/TanstackStoreWelcomeSurvey.repository.ts

@@ -6,7 +6,14 @@ import {
   type WelcomeSurveyStoreState,
 } from "@/domain/welcomeSurvey/WelcomeSurveyStore.config";
 
+// This module runs at import time both in the browser and, once the app is prerendered
+// (see the SEO PR later in the stack), under Node during a server-side render. Node has
+// no localStorage, so every access is guarded rather than assumed.
+const isBrowser = typeof localStorage !== "undefined";
+
 const loadInitialState = (): WelcomeSurveyStoreState => {
+  if (!isBrowser) return { survey: null };
+
   try {
     const stored = localStorage.getItem(WELCOME_SURVEY_KEY);
 
@@ -22,6 +29,8 @@ const loadInitialState = (): WelcomeSurveyStoreState => {
 const welcomeStore = new Store<WelcomeSurveyStoreState>(loadInitialState());
 
 welcomeStore.subscribe(() => {
+  if (!isBrowser) return;
+
   try {
     localStorage.setItem(WELCOME_SURVEY_KEY, JSON.stringify(welcomeStore.state));
   } catch (error) {

src/ui/components/WelcomeModal/WelcomeStorage/__spec__/LocalStorageWelcomeSurvey.repository.spec.ts

@@ -0,0 +1,61 @@
+/** @vitest-environment jsdom */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { WELCOME_SURVEY_KEY } from "@/domain/welcomeSurvey/WelcomeSurveyStore.config";
+import { LocalStorageWelcomeSurveyRepository } from "../LocalStorageWelcomeSurvey.repository";
+
+describe("LocalStorageWelcomeSurveyRepository", () => {
+  beforeEach(() => {
+    localStorage.clear();
+  });
+
+  it("should return null when nothing has been saved yet", () => {
+    const repository = new LocalStorageWelcomeSurveyRepository();
+
+    expect(repository.getSurvey()).toBeNull();
+  });
+
+  it("should persist and read back a saved survey", () => {
+    const repository = new LocalStorageWelcomeSurveyRepository();
+
+    repository.saveSurvey({ skill: "expert" });
+
+    expect(repository.getSurvey()).toEqual({ skill: "expert" });
+  });
+
+  it("should read a survey that was written to storage by another instance", () => {
+    const writer = new LocalStorageWelcomeSurveyRepository();
+    writer.saveSurvey({ skill: "intermediate" });
+
+    const reader = new LocalStorageWelcomeSurveyRepository();
+
+    expect(reader.getSurvey()).toEqual({ skill: "intermediate" });
+  });
+
+  it("should fall back to null for malformed stored data", () => {
+    localStorage.setItem(WELCOME_SURVEY_KEY, "not json");
+    const repository = new LocalStorageWelcomeSurveyRepository();
+
+    expect(repository.getSurvey()).toBeNull();
+  });
+
+  it("should notify subscribers when a survey is saved", () => {
+    const repository = new LocalStorageWelcomeSurveyRepository();
+    const listener = vi.fn();
+    repository.subscribe(listener);
+
+    repository.saveSurvey({ skill: "beginner" });
+
+    expect(listener).toHaveBeenCalledTimes(1);
+  });
+
+  it("should stop notifying once unsubscribed", () => {
+    const repository = new LocalStorageWelcomeSurveyRepository();
+    const listener = vi.fn();
+    const unsubscribe = repository.subscribe(listener);
+    unsubscribe();
+
+    repository.saveSurvey({ skill: "beginner" });
+
+    expect(listener).not.toHaveBeenCalled();
+  });
+});

src/ui/components/WelcomeModal/WelcomeStorage/__spec__/TanstackStoreWelcomeSurvey.repository.spec.ts

@@ -0,0 +1,35 @@
+// This file has no jsdom environment override, so it runs in vitest's default node
+// environment, which has no localStorage. That intentionally proves the module is safe
+// to import and use during a server-side render (see the SEO PR later in the stack).
+import { describe, expect, it, vi } from "vitest";
+import { TanStackStoreWelcomeSurveyRepository } from "../TanstackStoreWelcomeSurvey.repository";
+
+// TanStackStoreWelcomeSurveyRepository wraps one module-level store shared by every
+// instance, so these tests read back whatever the previous one just wrote rather than
+// assuming a clean starting state.
+describe("TanStackStoreWelcomeSurveyRepository (no localStorage)", () => {
+  it("should be importable and constructible without a DOM", () => {
+    expect(() => new TanStackStoreWelcomeSurveyRepository()).not.toThrow();
+  });
+
+  it("should save and read back a survey in memory", () => {
+    const repository = new TanStackStoreWelcomeSurveyRepository();
+
+    repository.saveSurvey({ skill: "expert" });
+
+    expect(repository.getSurvey()).toEqual({ skill: "expert" });
+  });
+
+  it("should notify and allow unsubscribing", () => {
+    const repository = new TanStackStoreWelcomeSurveyRepository();
+    const listener = vi.fn();
+    const unsubscribe = repository.subscribe(listener);
+
+    repository.saveSurvey({ skill: "beginner" });
+    expect(listener).toHaveBeenCalledTimes(1);
+
+    unsubscribe();
+    repository.saveSurvey({ skill: "intermediate" });
+    expect(listener).toHaveBeenCalledTimes(1);
+  });
+});