fix(anime): cap outcome polling and upstream stalls by wall clock

- watchPlaybackOutcome now tracks a real deadline so slow property reads eat the timeout budget instead of extending it, and a zero probe interval still terminates
- stream strip proxy aborts upstream GETs that go silent for 15s instead of hanging mpv on that segment forever
- anime browser runtime drops a stream proxy that finishes starting after its bridge already died, instead of leaking a listener pointed at nothing

src/anime-bridge/playback-outcome.test.ts

@@ -7,12 +7,25 @@ type Harness = {
   listenerCount: () => number;
   setProperty: (name: string, value: unknown) => void;
   failProperty: (name: string) => void;
+  /** Virtual milliseconds burned so far, by sleeps and by property reads. */
+  elapsed: () => number;
 };
 
-function createHarness(overrides?: { timeoutMs?: number; probeIntervalMs?: number }) {
+/**
+ * The clock is virtual and only moves when the code under test sleeps (or,
+ * with `readCostMs`, when it reads a property), so timeout behaviour is
+ * asserted without any real waiting.
+ */
+function createHarness(overrides?: {
+  timeoutMs?: number;
+  probeIntervalMs?: number;
+  readCostMs?: number;
+}) {
   const listeners = new Set<(event: PlaybackEndFileEvent) => void>();
   const properties = new Map<string, unknown>();
   const failing = new Set<string>();
+  const readCostMs = overrides?.readCostMs ?? 0;
+  let clock = 0;
 
   const watch = watchPlaybackOutcome({
     onEndFile: (listener) => {
@@ -20,10 +33,14 @@ function createHarness(overrides?: { timeoutMs?: number; probeIntervalMs?: numbe
       return () => listeners.delete(listener);
     },
     readProperty: async (name) => {
+      clock += readCostMs;
       if (failing.has(name)) throw new Error(`Failed to read MPV property '${name}'`);
       return properties.get(name);
     },
-    wait: async () => {},
+    wait: async (ms) => {
+      clock += ms;
+    },
+    now: () => clock,
     timeoutMs: overrides?.timeoutMs ?? 1000,
     probeIntervalMs: overrides?.probeIntervalMs ?? 100,
   });
@@ -35,6 +52,7 @@ function createHarness(overrides?: { timeoutMs?: number; probeIntervalMs?: numbe
     listenerCount: () => listeners.size,
     setProperty: (name, value) => properties.set(name, value),
     failProperty: (name) => failing.add(name),
+    elapsed: () => clock,
   };
   return { watch, harness };
 }
@@ -68,10 +86,32 @@ test('ignores the end-file fired for the file being replaced', async () => {
 });
 
 test('times out with a failure when nothing ever starts', async () => {
-  const { watch } = createHarness({ timeoutMs: 300, probeIntervalMs: 100 });
+  const { watch, harness } = createHarness({ timeoutMs: 300, probeIntervalMs: 100 });
   const outcome = await watch.wait();
   assert.equal(outcome.ok, false);
   assert.ok(!outcome.ok && outcome.error.length > 0);
+  assert.equal(harness.elapsed(), 300);
+  watch.dispose();
+});
+
+test('slow property reads eat the budget instead of extending it', async () => {
+  const { watch, harness } = createHarness({
+    timeoutMs: 300,
+    probeIntervalMs: 100,
+    readCostMs: 250,
+  });
+  const outcome = await watch.wait();
+  assert.equal(outcome.ok, false);
+  // Two probes: 250 + 50 (the sleep clamped to what was left) then 250 again.
+  assert.ok(harness.elapsed() >= 300, 'gave up before the timeout');
+  assert.ok(harness.elapsed() < 900, 'read delays stretched the timeout');
+  watch.dispose();
+});
+
+test('a zero probe interval still terminates at the deadline', async () => {
+  const { watch } = createHarness({ timeoutMs: 200, probeIntervalMs: 0, readCostMs: 50 });
+  const outcome = await watch.wait();
+  assert.equal(outcome.ok, false);
   watch.dispose();
 });
 

src/anime-bridge/playback-outcome.ts

@@ -26,6 +26,8 @@ export interface WatchPlaybackOutcomeDeps {
   /** One-shot mpv property read; may reject while the file is still loading. */
   readProperty: (name: string) => Promise<unknown>;
   wait: (ms: number) => Promise<void>;
+  /** Injectable clock; the timeout is wall-clock, not a probe count. */
+  now?: () => number;
   timeoutMs?: number;
   probeIntervalMs?: number;
 }
@@ -58,7 +60,11 @@ export function watchPlaybackOutcome(deps: WatchPlaybackOutcomeDeps): PlaybackOu
   });
 
   async function wait(): Promise<PlaybackOutcome> {
-    for (let elapsed = 0; elapsed < timeoutMs; elapsed += probeIntervalMs) {
+    // Wall-clock, not a probe count: a slow `readProperty` must eat into the
+    // budget rather than stretch it, and a zero probe interval must still end.
+    const now = deps.now ?? Date.now;
+    const deadline = now() + timeoutMs;
+    while (now() < deadline) {
       if (failure) return failure;
       try {
         if ((await deps.readProperty('vo-configured')) === true) return { ok: true };
@@ -66,7 +72,10 @@ export function watchPlaybackOutcome(deps: WatchPlaybackOutcomeDeps): PlaybackOu
         // The property is unreadable while mpv is between files; keep polling.
       }
       if (failure) return failure;
-      await deps.wait(probeIntervalMs);
+      // Sleeping past the deadline would only delay the timeout report.
+      const remaining = deadline - now();
+      if (remaining <= 0) break;
+      await deps.wait(Math.min(probeIntervalMs, remaining));
     }
     return (
       failure ?? {

src/anime-bridge/stream-strip-proxy.test.ts

@@ -64,11 +64,16 @@ test('rewritePlaylistOrigins swaps absolute upstream URLs and keeps relative lin
 
 type Route = { status: number; contentType: string; body: Buffer };
 
+/** Either a static routing table or a handler, for upstreams that need one. */
 async function withProxy(
-  routes: Record<string, Route>,
+  routes: Record<string, Route> | http.RequestListener,
   run: (proxyOrigin: string, upstreamOrigin: string) => Promise<void>,
 ): Promise<void> {
   const upstream = http.createServer((req, res) => {
+    if (typeof routes === 'function') {
+      routes(req, res);
+      return;
+    }
     const route = routes[req.url ?? ''];
     if (!route) {
       res.writeHead(404).end('missing');
@@ -133,63 +138,54 @@ test('proxy leaves non-TS bodies alone', async () => {
 });
 
 test('proxy rewrites absolute upstream playlist entries to its own origin', async () => {
-  const upstream = http.createServer((req, res) => {
-    const origin = `http://127.0.0.1:${(upstream.address() as AddressInfo).port}`;
-    if (req.url === '/video/list.m3u8') {
+  await withProxy(
+    (req, res) => {
+      if (req.url !== '/video/list.m3u8') {
+        res.writeHead(404).end();
+        return;
+      }
+      // The proxy rewrites the Host header to the upstream it dialled, so this
+      // is that origin — the one the playlist must not leak to mpv.
       res.writeHead(200, { 'content-type': 'application/vnd.apple.mpegurl' });
-      res.end(`#EXTM3U\n#EXTINF:6,\n${origin}/video/abs.ts\n`);
-      return;
-    }
-    res.writeHead(404).end();
-  });
-  await new Promise<void>((resolve) => upstream.listen(0, '127.0.0.1', resolve));
-  const upstreamOrigin = `http://127.0.0.1:${(upstream.address() as AddressInfo).port}`;
-  const proxy = await startStreamStripProxy({ upstreamOrigin: () => upstreamOrigin });
-  try {
-    const { body } = await fetchBytes(`${proxy.origin}/video/list.m3u8`);
-    const text = body.toString('utf8');
-    assert.ok(text.includes(`${proxy.origin}/video/abs.ts`));
-    assert.ok(!text.includes(upstreamOrigin));
-  } finally {
-    await proxy.close();
-    await new Promise<void>((resolve) => upstream.close(() => resolve()));
-  }
+      res.end(`#EXTM3U\n#EXTINF:6,\nhttp://${req.headers.host}/video/abs.ts\n`);
+    },
+    async (proxyOrigin, upstreamOrigin) => {
+      const { body } = await fetchBytes(`${proxyOrigin}/video/list.m3u8`);
+      const text = body.toString('utf8');
+      assert.ok(text.includes(`${proxyOrigin}/video/abs.ts`));
+      assert.ok(!text.includes(upstreamOrigin));
+    },
+  );
 });
 
 test('proxy strips even when the client asks for a byte range', async () => {
-  // ffmpeg opens every HLS segment with `Range: bytes=0-`; the bridge answers
-  // some of those with 206, which must not bypass the strip.
+  // ffmpeg opens every HLS segment with `Range: bytes=0-`. The proxy drops the
+  // header, so the upstream answers 200 with the whole body and the strip
+  // applies; a 206 would have been forwarded untouched.
   const ts = makeTsPackets(8);
   const disguised = Buffer.concat([PNG_HEADER, ts]);
-  const upstream = http.createServer((req, res) => {
-    if (req.headers.range !== undefined) {
-      res.writeHead(206, {
-        'content-type': 'image/png',
-        'content-range': `bytes 0-${disguised.length - 1}/${disguised.length}`,
-      });
+  await withProxy(
+    (req, res) => {
+      if (req.headers.range !== undefined) {
+        res.writeHead(206, {
+          'content-type': 'image/png',
+          'content-range': `bytes 0-${disguised.length - 1}/${disguised.length}`,
+        });
+        res.end(disguised);
+        return;
+      }
+      res.writeHead(200, { 'content-type': 'image/png' });
       res.end(disguised);
-      return;
-    }
-    res.writeHead(200, { 'content-type': 'image/png' });
-    res.end(disguised);
-  });
-  await new Promise<void>((resolve) => upstream.listen(0, '127.0.0.1', resolve));
-  const upstreamOrigin = `http://127.0.0.1:${(upstream.address() as AddressInfo).port}`;
-  const proxy = await startStreamStripProxy({
-    upstreamOrigin: () => upstreamOrigin,
-    retryDelayMs: 5,
-  });
-  try {
-    const response = await fetch(`${proxy.origin}/video/seg.ts`, {
-      headers: { Range: 'bytes=0-' },
-    });
-    const body = Buffer.from(await response.arrayBuffer());
-    assert.equal(response.status, 200);
-    assert.deepEqual(body, ts);
-  } finally {
-    await proxy.close();
-    await new Promise<void>((resolve) => upstream.close(() => resolve()));
-  }
+    },
+    async (proxyOrigin) => {
+      const response = await fetch(`${proxyOrigin}/video/seg.ts`, {
+        headers: { Range: 'bytes=0-' },
+      });
+      const body = Buffer.from(await response.arrayBuffer());
+      assert.equal(response.status, 200);
+      assert.deepEqual(body, ts);
+    },
+  );
 });
 
 test('proxy forwards error statuses without touching the body', async () => {

src/anime-bridge/stream-strip-proxy.ts

@@ -73,6 +73,12 @@ export interface StreamStripProxyOptions {
 }
 
 const DEFAULT_RETRY_DELAY_MS = 400;
+/**
+ * Socket timeout on the upstream GET, cleared once its headers arrive. Node's
+ * http client has no deadline of its own, so a host that accepts the
+ * connection and then says nothing would hang mpv on that segment forever.
+ */
+const UPSTREAM_TIMEOUT_MS = 15_000;
 
 export interface StreamStripProxyHandle {
   origin: string;
@@ -152,8 +158,10 @@ export function startStreamStripProxy(
 
     const upstreamRequest = http.request(
       upstreamUrl,
-      { method: req.method, headers: requestHeaders },
+      { method: req.method, headers: requestHeaders, timeout: UPSTREAM_TIMEOUT_MS },
       (upstream) => {
+        // Body streaming has its own pace; only the wait for headers is capped.
+        upstreamRequest.setTimeout(0);
         const status = upstream.statusCode ?? 502;
         if (status === 404 || status >= 500) {
           if (mayRetry) {
@@ -167,6 +175,10 @@ export function startStreamStripProxy(
         handleUpstreamResponse(req, res, upstream);
       },
     );
+    // Destroying with an error routes the stall through the retry/502 path.
+    upstreamRequest.on('timeout', () => {
+      upstreamRequest.destroy(new Error(`upstream silent for ${UPSTREAM_TIMEOUT_MS}ms`));
+    });
     upstreamRequest.on('error', (error) => {
       if (mayRetry) {
         log(`[stream-proxy] upstream request failed: ${String(error)}; retrying once`);