fix(tests): stop feed-store mock.module leak that broke the full suite

discover-store-preview mocked src/stores/feed via mock.module, which bun
applies process-globally: with workers reused across test files, every file
that later shared a worker imported the stub (fetchEpisodes only) and failed
with 'addFeed is not a function' — ~35 tests, drifting run to run with worker
scheduling. Rewrote the test against the REAL feed store and a local gated
Bun.serve server (repo-dominant harness), importing the discover store via a
query-suffixed specifier so a sibling discover-store mock cannot leak in.
Full suite: 215 pass, 0 fail (baseline: 194).

tests/discover-store-preview.test.ts

@@ -4,30 +4,99 @@
  * `openEpisodes` fetches a show's RSS feed WITHOUT subscribing (drill-in from
  * a podcast result), caches it per podcast id for the session, records a
  * per-show error on failure, and never refetches while cached or in flight.
- * `refreshEpisodes` clears the cache/error and refetches. The feed store is
+ * `refreshEpisodes` clears the cache/error and refetches.
- * mocked so the network never runs; the cache-hit/in-flight/error contracts
+ *
- * are what this file defends.
+ * The REAL feed store runs against a local RSS server. No `mock.module`:
+ * bun test reuses workers across files and module mocks leak into the shared
+ * registry, so a feed-store mock here (whose stub lacks addFeed/refreshFeed/
+ * isLoadingFeeds) breaks every later file that shares a worker — the suite's
+ * documented failure mode. The repo's defense is importing the REAL modules
+ * via a query-suffixed specifier, which `mock.module` does not intercept.
  */
 
-import { test, expect, mock } from "bun:test";
+import { test, expect, beforeAll, afterAll } from "bun:test";
+import { mkdtempSync, rmSync } from "fs";
+import { tmpdir } from "os";
+import { join } from "path";
 import type { Podcast } from "../src/types/podcast";
-import type { Episode } from "../src/types/episode";
 
-const fetchCalls: string[] = [];
+// Point the config dir at a throwaway directory BEFORE importing the stores
-const mockFeedStore = {
+// (their module-level init reads it).
-	fetchEpisodes: async (feedUrl: string, limit: number) => {
+const configHome = mkdtempSync(join(tmpdir(), "podtui-discprev-"));
-		fetchCalls.push(feedUrl);
+process.env.XDG_CONFIG_HOME = configHome;
-		return {
-			episodes: [makeEpisode("ep-1")] as Episode[] | null,
-			coverUrl: undefined,
-		};
-	},
-};
-mock.module("../src/stores/feed", () => ({
-	useFeedStore: () => mockFeedStore,
-}));
 
-const { useDiscoverStore } = await import("../src/stores/discover");
+// Query-suffixed module identity: loads the REAL discover store even when a
+// sibling file's `mock.module("../src/stores/discover")` leaked into this
+// worker. Its internal `./feed` import resolves the real feed store, which
+// no file mocks anymore.
+// @ts-expect-error — bun-only query suffix: distinct module identity that
+// loads the real file instead of a leaked mock.module from another test file.
+const { useDiscoverStore } = await import("../src/stores/discover?discover-store-preview");
+
+interface ServedEpisode {
+	title: string;
+	date: string;
+}
+
+/** Pathnames the local server has served, in order (fetch tracking). */
+const requests: string[] = [];
+/** Per-path episode lists served by the local server. */
+const served: Record<string, ServedEpisode[]> = {};
+/** When set, responses for this path wait on the release callback. */
+let gatePath: string | null = null;
+let releaseGate: (() => void) | null = null;
+
+/** XML for one show's episode list (ids derive from enclosure URLs). */
+function feedXml(episodes: ServedEpisode[], origin: string): string {
+	const items = episodes
+		.map(
+			(ep, i) => `<item>
+	<title>${ep.title}</title>
+	<pubDate>${ep.date}</pubDate>
+	<enclosure url="${origin}/audio-${i}.mp3" length="12345" type="audio/mpeg"/>
+</item>`,
+		)
+		.join("\n");
+	return `<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0"><channel>
+<title>Test Show</title>
+<description>Discover preview test feed</description>
+${items}
+</channel></rss>`;
+}
+
+let server: Bun.Server<undefined> | null = null;
+let origin = "";
+
+beforeAll(() => {
+	server = Bun.serve({
+		port: 0,
+		async fetch(req) {
+			const url = new URL(req.url);
+			requests.push(url.pathname);
+			if (gatePath && url.pathname === gatePath) {
+				await new Promise<void>((resolve) => {
+					releaseGate = resolve;
+				});
+			}
+			// A permanently-failing feed (simulates a show that went down).
+			if (url.pathname === "/fail.xml") {
+				return new Response("feed unavailable", { status: 503 });
+			}
+			const eps = served[url.pathname];
+			if (!eps) return new Response("not found", { status: 404 });
+			return new Response(feedXml(eps, url.origin), {
+				headers: { "Content-Type": "application/rss+xml" },
+			});
+		},
+	});
+	origin = `http://127.0.0.1:${server.port}`;
+});
+
+afterAll(() => {
+	server?.stop(true);
+	rmSync(configHome, { recursive: true, force: true });
+});
 
 function makePodcast(overrides: Partial<Podcast> = {}): Podcast {
 	return {
@@ -41,54 +110,45 @@ function makePodcast(overrides: Partial<Podcast> = {}): Podcast {
 	};
 }
 
-function makeEpisode(id: string): Episode {
-	return {
-		id,
-		podcastId: "show-1",
-		title: `Ep ${id}`,
-		description: "",
-		audioUrl: "https://example.test/ep.mp3",
-		duration: 0,
-		pubDate: new Date("2026-08-01T00:00:00Z"),
-	};
-}
-
 test("openEpisodes fetches, caches, and never refetches on cache hit or in flight", async () => {
 	const store = useDiscoverStore();
-	const pod = makePodcast();
+	const pod = makePodcast({ feedUrl: `${origin}/show1.xml` });
+	served["/show1.xml"] = [{ title: "Ep 1", date: "2026-08-10T00:00:00Z" }];
 
 	expect(store.episodesForPodcast(pod.id)).toHaveLength(0);
 
 	await store.openEpisodes(pod);
-	expect(fetchCalls).toEqual([pod.feedUrl]);
+	expect(requests).toEqual(["/show1.xml"]);
 	expect(store.episodesForPodcast(pod.id)).toHaveLength(1);
-	expect(store.episodesForPodcast(pod.id)[0].id).toBe("ep-1");
+	expect(store.episodesForPodcast(pod.id)[0].title).toBe("Ep 1");
 	expect(store.isLoadingEpisodesFor(pod.id)).toBe(false);
 	expect(store.previewError(pod.id)).toBeUndefined();
 
 	// Cache hit: second open must not refetch.
 	await store.openEpisodes(pod);
-	expect(fetchCalls).toHaveLength(1);
+	expect(requests).toEqual(["/show1.xml"]);
 
 	// In-flight guard: a concurrent open during loading must not refetch.
-	const slow = mockFeedStore.fetchEpisodes;
+	// The server holds this show's response until the gate is released.
-	const gate = Promise.withResolvers<void>();
+	const pod2 = makePodcast({ id: "show-2", feedUrl: `${origin}/slow.xml` });
-	mockFeedStore.fetchEpisodes = async (feedUrl: string, limit: number) => {
+	served["/slow.xml"] = [{ title: "Ep 2", date: "2026-08-09T00:00:00Z" }];
-		fetchCalls.push(feedUrl);
+	gatePath = "/slow.xml";
-		await gate.promise;
-		return { episodes: [makeEpisode("ep-2")] as Episode[] | null, coverUrl: undefined };
-	};
-	const pod2 = makePodcast({ id: "show-2", feedUrl: "https://example.test/feed2.xml" });
 	const pending = store.openEpisodes(pod2);
 	// Loading is set synchronously before the fetch resolves.
 	expect(store.isLoadingEpisodesFor(pod2.id)).toBe(true);
 	await store.openEpisodes(pod2); // must early-return, not queue a second fetch
-	gate.resolve();
+	// The request is held by the server gate; wait until it was actually
+	// received so the assertion isn't racing the network.
+	const deadline = Date.now() + 1000;
+	while (requests.length < 2 && Date.now() < deadline) {
+		await new Promise((r) => setTimeout(r, 5));
+	}
+	expect(requests).toEqual(["/show1.xml", "/slow.xml"]);
+	releaseGate?.();
+	gatePath = null;
 	await pending;
-	expect(fetchCalls).toEqual([pod.feedUrl, pod2.feedUrl]);
+	expect(store.episodesForPodcast(pod2.id)[0].title).toBe("Ep 2");
-	expect(store.episodesForPodcast(pod2.id)[0].id).toBe("ep-2");
 	expect(store.isLoadingEpisodesFor(pod2.id)).toBe(false);
-	mockFeedStore.fetchEpisodes = slow;
 });
 
 test("openEpisodes records an error for feedless shows and failed fetches", async () => {
@@ -96,34 +156,29 @@ test("openEpisodes records an error for feedless shows and failed fetches", asyn
 	const feedless = makePodcast({ id: "show-3", feedUrl: undefined });
 
 	await store.openEpisodes(feedless);
-	expect(fetchCalls).not.toContain(feedless.id);
+	expect(requests).not.toContain(feedless.id);
 	expect(store.previewError(feedless.id)).toBe("No RSS feed listed for this show.");
 	expect(store.episodesForPodcast(feedless.id)).toHaveLength(0);
 
-	// Failed fetch (null episodes) → error recorded, nothing cached.
+	// Failed fetch (server 503) → error recorded, nothing cached.
-	const original = mockFeedStore.fetchEpisodes;
+	const failing = makePodcast({ id: "show-4", feedUrl: `${origin}/fail.xml` });
-	mockFeedStore.fetchEpisodes = async () => ({
-		episodes: null,
-		coverUrl: undefined,
-	});
-	const failing = makePodcast({ id: "show-4" });
 	await store.openEpisodes(failing);
 	expect(store.previewError(failing.id)).toBe("Couldn't load episodes.");
 	expect(store.episodesForPodcast(failing.id)).toHaveLength(0);
 	expect(store.isLoadingEpisodesFor(failing.id)).toBe(false);
-	mockFeedStore.fetchEpisodes = original;
 });
 
 test("refreshEpisodes clears the cache and error, then refetches", async () => {
 	const store = useDiscoverStore();
-	const pod = makePodcast({ id: "show-5" });
+	const pod = makePodcast({ id: "show-5", feedUrl: `${origin}/show5.xml` });
+	served["/show5.xml"] = [{ title: "Ep 1", date: "2026-08-10T00:00:00Z" }];
 
 	await store.openEpisodes(pod);
 	expect(store.episodesForPodcast(pod.id)).toHaveLength(1);
-	const callsBefore = fetchCalls.length;
+	const callsBefore = requests.length;
 
 	await store.refreshEpisodes(pod);
-	expect(fetchCalls.length).toBe(callsBefore + 1);
+	expect(requests.length).toBe(callsBefore + 1);
 	expect(store.episodesForPodcast(pod.id)).toHaveLength(1);
 	expect(store.previewError(pod.id)).toBeUndefined();
 });