Improve unit test.

src/libs/store/stylestore.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect, beforeEach, vi } from "vitest";
+import { StyleStore } from "./stylestore";
 
-// StyleStore reads/writes window.localStorage; provide a minimal in-memory mock.
 class LocalStorageMock {
   private store: Record<string, string> = {};
   get length() {
@@ -22,15 +22,14 @@ class LocalStorageMock {
     this.store = {};
   }
 }
-
 vi.stubGlobal("window", { localStorage: new LocalStorageMock() });
-
-// Avoid network in loadDefaultStyle.
-vi.mock("../urlopen", () => ({
-  loadStyleUrl: vi.fn(async () => ({ version: 8, id: "default", sources: {}, layers: [] })),
-}));
-
-import { StyleStore } from "./stylestore";
+// loadDefaultStyle fetches the default style over the network; serve it locally.
+vi.stubGlobal(
+  "fetch",
+  vi.fn(async () => ({
+    json: async () => ({ version: 8, id: "default", sources: {}, layers: [] }),
+  }))
+);
 
 const style = (id: string) => ({ version: 8, id, sources: {}, layers: [] }) as any;
 
@@ -47,7 +46,7 @@ describe("StyleStore", () => {
 
   it("saves a style and reads it back as the latest", async () => {
     const store = new StyleStore();
-    await store.save(style("abc"));
+    store.save(style("abc"));
     // A fresh store discovers the persisted style ids.
     const reopened = new StyleStore();
     const latest = await reopened.getLatestStyle();
@@ -56,7 +55,7 @@ describe("StyleStore", () => {
 
   it("purge removes all maputnik keys", async () => {
     const store = new StyleStore();
-    await store.save(style("abc"));
+    store.save(style("abc"));
     window.localStorage.setItem("unrelated", "keep");
     store.purge();
     expect(window.localStorage.getItem("maputnik:style:abc")).toBeNull();