fix(providers): validate before limiting and tighten capped image reads

Apply shared Places validation, owned image chunks, and response-header deadline tests to the provider modules.

src/data/cctvProxy.test.mjs

@@ -1,9 +1,27 @@
+import { CCTV_FRAME_FETCH_TIMEOUT_MS, CCTV_FRAME_MAX_BODY_BYTES, CCTV_MEDIA_FETCH_TIMEOUT_MS, CCTV_MEDIA_MAX_BODY_BYTES } from '../../server/providers/cctv/constants.js';
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import {
-  CCTV_FRAME_FETCH_TIMEOUT_MS,
   fetchCctvImageFromUpstream,
-} from '../../vite.config.js';
+  fetchCctvMediaUpstream,
+} from '../../server/providers/cctv/media.js';
+
+/** A body that arrives in chunks and never declares a Content-Length. */
+function chunkedImageResponse(chunkBytes, chunkCount, { onChunk = () => {}, onCancel = () => {} } = {}) {
+  const stream = new ReadableStream({
+    async pull(controller) {
+      if (chunkCount <= 0) {
+        controller.close();
+        return;
+      }
+      chunkCount -= 1;
+      onChunk();
+      controller.enqueue(new Uint8Array(chunkBytes));
+    },
+    cancel: onCancel,
+  });
+  return new Response(stream, { status: 200, headers: { 'Content-Type': 'image/jpeg' } });
+}
 
 test('CCTV upstream frame fetch supplies a bounded abort signal', async () => {
   let observedSignal = null;
@@ -36,3 +54,161 @@ test('CCTV upstream frame fetch returns a valid image response', async () => {
   assert.equal(result?.contentType, 'image/jpeg');
   assert.deepEqual(result?.body, Buffer.from([1, 2, 3]));
 });
+
+test('CCTV upstream frame fetch rejects a declared oversize body without draining it', async () => {
+  const chunkBytes = 64 * 1024;
+  let pulled = 0;
+  let cancelled = false;
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: chunkBytes * 4,
+    fetchImpl: async () => {
+      const response = chunkedImageResponse(chunkBytes, 64, {
+        onChunk: () => { pulled += 1; },
+        onCancel: () => { cancelled = true; },
+      });
+      response.headers.set('Content-Length', String(chunkBytes * 64));
+      return response;
+    },
+  });
+
+  // Assert on the byte count, not the object: a regressed proxy returns a
+  // multi-megabyte Buffer here, and diffing one into the failure report is
+  // slower than the check it is reporting on.
+  assert.equal(result?.body?.length ?? null, null, 'a declared oversize snapshot is a miss, not a buffered body');
+  assert.equal(cancelled, true, 'the declared cap is enforced by cancelling, not reading');
+  // Only the stream's own one-chunk prefetch may have run; the proxy pulls none.
+  assert.ok(pulled <= 1, `declared cap short-circuits the read, pulled ${pulled} chunks`);
+});
+
+test('CCTV upstream frame fetch aborts an undeclared body once it crosses the cap', async () => {
+  const chunkBytes = 64 * 1024;
+  let pulled = 0;
+  let cancelled = false;
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: chunkBytes * 4,
+    // Sixty-four chunks are offered with no Content-Length; a proxy that
+    // buffers first would take all of them.
+    fetchImpl: async () => chunkedImageResponse(chunkBytes, 64, {
+      onChunk: () => { pulled += 1; },
+      onCancel: () => { cancelled = true; },
+    }),
+  });
+
+  assert.equal(result?.body?.length ?? null, null, 'a chunked body over the cap is a miss');
+  // Four chunks fit, the fifth crosses the cap, and one more sits in the
+  // stream's prefetch queue — nothing past that is ever pulled.
+  assert.ok(pulled <= 6, `stopped reading at the cap, pulled ${pulled} chunks`);
+  assert.equal(cancelled, true, 'the upstream stream is cancelled, not drained');
+});
+
+test('CCTV upstream frame fetch still returns a chunked body under the cap', async () => {
+  const chunkBytes = 1024;
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: chunkBytes * 8,
+    fetchImpl: async () => chunkedImageResponse(chunkBytes, 3),
+  });
+
+  assert.equal(result?.ok, true);
+  assert.equal(result?.body?.length, chunkBytes * 3, 'every chunk is reassembled in order');
+  assert.ok(CCTV_FRAME_MAX_BODY_BYTES > 0 && CCTV_FRAME_MAX_BODY_BYTES <= CCTV_MEDIA_MAX_BODY_BYTES,
+    'the frame cap must be at or under the media route cap — pinned against the real constant');
+});
+
+test('CCTV media upstream fetch aborts when response headers never arrive', async () => {
+  let observedSignal = null;
+  const startedAt = Date.now();
+  await assert.rejects(
+    fetchCctvMediaUpstream('https://example.com/stream.m3u8', {
+      timeoutMs: 25,
+      fetchImpl: (url, { signal }) => new Promise((resolve, reject) => {
+        observedSignal = signal;
+        signal.addEventListener('abort', () => reject(Object.assign(new Error('aborted'), { name: 'AbortError' })));
+      }),
+    }),
+    (error) => error.name === 'AbortError',
+  );
+  assert.equal(observedSignal?.aborted, true, 'the header deadline aborts the attempt');
+  assert.ok(Date.now() - startedAt < 2_000, 'the deadline is the injected one, not the production one');
+  assert.ok(CCTV_MEDIA_FETCH_TIMEOUT_MS >= 10_000, 'production keeps a generous header deadline for slow cameras');
+});
+
+test('CCTV media upstream fetch never cuts a stream whose headers arrived in time', async () => {
+  let observedSignal = null;
+  const upstream = await fetchCctvMediaUpstream('https://example.com/stream.m3u8', {
+    timeoutMs: 20,
+    fetchImpl: async (url, { signal }) => {
+      observedSignal = signal;
+      return { ok: true, status: 200, headers: new Map([['content-type', 'video/mp2t']]), body: null };
+    },
+  });
+  assert.equal(upstream.ok, true);
+  // Well past the header deadline: the timer was cleared at header arrival,
+  // so the live body is still allowed to flow.
+  await new Promise((resolve) => setTimeout(resolve, 60));
+  assert.equal(observedSignal?.aborted, false, 'a slow body after timely headers is never aborted here');
+});
+
+test('CCTV upstream frame fetch keeps a body that lands exactly on the cap', async () => {
+  const chunkBytes = 512;
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: chunkBytes * 4,
+    fetchImpl: async () => chunkedImageResponse(chunkBytes, 4),
+  });
+  assert.equal(result?.ok, true, 'exactly-at-cap is under the ceiling, not over it');
+  assert.equal(result?.body?.length, chunkBytes * 4);
+});
+
+test('CCTV upstream frame fetch ignores a garbage Content-Length and still caps the stream', async () => {
+  const chunkBytes = 1024;
+  let cancelled = false;
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: chunkBytes * 2,
+    fetchImpl: async () => {
+      const response = chunkedImageResponse(chunkBytes, 8, { onCancel: () => { cancelled = true; } });
+      response.headers.set('Content-Length', 'not-a-number');
+      return response;
+    },
+  });
+  assert.equal(result?.body?.length ?? null, null, 'an unparseable length falls back to counting bytes');
+  assert.equal(cancelled, true);
+});
+
+test('CCTV upstream frame fetch retains owned bytes, not the chunk\'s backing allocation', async () => {
+  const backing = new ArrayBuffer(4 * 1024 * 1024);
+  const view = new Uint8Array(backing, 8, 3);
+  view.set([7, 8, 9]);
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: 1024,
+    fetchImpl: async () => new Response(new ReadableStream({
+      start(controller) {
+        controller.enqueue(view);
+        controller.close();
+      },
+    }), { status: 200, headers: { 'Content-Type': 'image/jpeg' } }),
+  });
+  assert.equal(result?.ok, true);
+  assert.deepEqual(Array.from(result.body), [7, 8, 9]);
+  assert.ok(result.body.buffer.byteLength < backing.byteLength,
+    'the 4 MB backing allocation is not retained behind a 3-byte frame');
+});
+
+test('CCTV upstream frame fetch refuses a body it cannot stream instead of buffering it uncapped', async () => {
+  const result = await fetchCctvImageFromUpstream('https://example.com/frame.jpg', {
+    timeoutMs: 1000,
+    maxBytes: 1024,
+    fetchImpl: async () => ({
+      ok: true,
+      status: 200,
+      headers: new Map([['content-type', 'image/jpeg']]),
+      body: { /* neither async-iterable nor reader-backed */ },
+      arrayBuffer: async () => { throw new Error('arrayBuffer must never be used as an uncapped fallback'); },
+    }),
+  });
+  assert.equal(result, null);
+});