Automatically prepare the bundled Navidrome sidecar and replace demo content with real-library scan states and polling

Hop-State: A_06FNEE4FJ502PSGDYQ3272G
Hop-Proposal: R_06FNED6AR1ZZM7CJH7ETC9G
Hop-Task: T_06FNEAPFW0DYEP35V3BMAHG
Hop-Attempt: AT_06FNEAPFW1QY3KAF1QM61N0

src/lib/librarySync.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it, vi } from "vitest";
+import { pollForLibrary } from "./librarySync";
+
+describe("pollForLibrary", () => {
+  it("waits until Navidrome returns indexed tracks", async () => {
+    const load = vi.fn()
+      .mockRejectedValueOnce(new Error("server is still starting"))
+      .mockResolvedValueOnce({ tracks: [] })
+      .mockResolvedValueOnce({ tracks: [] })
+      .mockResolvedValueOnce({ tracks: [{ id: "real-track" }] });
+    const wait = vi.fn().mockResolvedValue(undefined);
+
+    await expect(pollForLibrary(load, { attempts: 5, wait })).resolves.toEqual({
+      tracks: [{ id: "real-track" }],
+    });
+    expect(load).toHaveBeenCalledTimes(4);
+    expect(wait).toHaveBeenCalledTimes(3);
+  });
+
+  it("returns null when the scan never yields a track", async () => {
+    const load = vi.fn().mockResolvedValue({ tracks: [] });
+    const wait = vi.fn().mockResolvedValue(undefined);
+
+    await expect(pollForLibrary(load, { attempts: 3, wait })).resolves.toBeNull();
+    expect(load).toHaveBeenCalledTimes(3);
+  });
+});

src/lib/librarySync.ts

@@ -0,0 +1,27 @@
+export interface LibrarySnapshot<TTrack> {
+  tracks: readonly TTrack[];
+}
+
+interface PollOptions {
+  attempts?: number;
+  delayMs?: number;
+  wait?: (delayMs: number) => Promise<void>;
+}
+
+const waitFor = (delayMs: number) => new Promise<void>((resolve) => window.setTimeout(resolve, delayMs));
+
+export async function pollForLibrary<T extends LibrarySnapshot<unknown>>(
+  load: () => Promise<T>,
+  { attempts = 120, delayMs = 1_000, wait = waitFor }: PollOptions = {},
+): Promise<T | null> {
+  for (let attempt = 0; attempt < attempts; attempt += 1) {
+    try {
+      const snapshot = await load();
+      if (snapshot.tracks.length > 0) return snapshot;
+    } catch (error) {
+      if (attempt === attempts - 1) throw error;
+    }
+    if (attempt < attempts - 1) await wait(delayMs);
+  }
+  return null;
+}