diff --git a/.forgejo/workflows/publish-docker.yml b/.forgejo/workflows/publish-docker.yml
index 7946cb8..f536d91 100644
--- a/.forgejo/workflows/publish-docker.yml
+++ b/.forgejo/workflows/publish-docker.yml
@@ -17,8 +17,13 @@
 #     read:package (Forgejo -> Settings -> Applications), le jeton
 #     automatique de l'Action n'a pas ce droit.
 #
-# Pas de job de test : ce projet n'a pas de suite de tests pour l'instant
-# (contrairement à mediaDrop) - à ajouter ici le jour où il y en a une.
+# Deux jobs :
+#  - test    : typecheck + tests serveur (node:test, voir server/test/) et
+#              typecheck + build client, dans un conteneur node:20-alpine
+#              (docker:27-cli n'a pas Node, donc un conteneur séparé).
+#  - publish : build + push l'image Docker, seulement si `test` passe
+#              (needs: test) - clone les sources une seconde fois dans son
+#              propre conteneur, les deux jobs ne partagent pas de filesystem.
 
 name: Publier l'image Docker
 
@@ -37,7 +42,49 @@ env:
   IMAGE: git.dev.kyuno.fr/${{ github.repository_owner }}/watchparty
 
 jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: node:20-alpine
+    steps:
+      # node:20-alpine n'a pas git préinstallé - même approche de clone
+      # manuel que le job publish (pas d'actions/checkout, action JS qui a
+      # ses propres soucis dans les conteneurs Alpine minimalistes ici).
+      - name: Récupérer les sources
+        run: |
+          set -eu
+          apk add --no-cache git
+          git init -q
+          git remote add origin "${{ github.server_url }}/${{ github.repository }}.git"
+          git fetch -q --depth 1 origin "${{ github.ref_name }}"
+          git checkout -q FETCH_HEAD
+
+      - name: Serveur - installer les dépendances
+        working-directory: server
+        run: npm ci
+
+      - name: Serveur - vérifier les types (src/ + test/)
+        working-directory: server
+        run: npm run typecheck
+
+      - name: Serveur - lancer la suite de tests
+        working-directory: server
+        run: npm test
+
+      - name: Client - installer les dépendances
+        working-directory: client
+        run: npm ci
+
+      - name: Client - vérifier les types
+        working-directory: client
+        run: npm run typecheck
+
+      - name: Client - build (esbuild)
+        working-directory: client
+        run: npm run build
+
   publish:
+    needs: test
     runs-on: ubuntu-latest
     container:
       image: docker:27-cli
diff --git a/README.md b/README.md
index 43ced21..50d3a3c 100644
--- a/README.md
+++ b/README.md
@@ -59,15 +59,20 @@ albums/tracks, `PlaybackInfo`'s media streams) and actual HLS playback
 (video or audio) are still unverified.
 
 The TypeScript rewrite itself is separately verified: both projects
-type-check in strict mode, the compiled server passes the same
-unit/integration tests the pre-rewrite JS did (run against the compiled
-output, not the source), and the compiled+bundled client was driven
-through every page and both players end to end (mocked network/Socket.IO)
-in a real browser. **Not verified**: an actual `docker build` of the new
-multi-stage Dockerfile - this dev environment has no Docker - so treat the
-first real build as the thing to double-check, even though it mirrors
-exactly the `npm run build` commands already confirmed working locally
-for both projects.
+type-check in strict mode, the server has a real automated test suite
+(`server/test/*.test.ts`, Node's built-in test runner, see Running
+locally below) covering the party lifecycle, the music queue's
+timer/vote/pause behavior, the socket protocol, and the catalog/streaming
+overrides, and the compiled+bundled client was driven through every page
+and both players end to end (mocked network/Socket.IO) in a real browser.
+CI (Forgejo Actions) runs that same typecheck+test+build sequence on
+every push and gates the Docker image publish on it passing — see
+[docs/architecture.md](docs/architecture.md#continuous-integration).
+**Not verified**: an actual `docker build` of the new multi-stage
+Dockerfile - this dev environment has no Docker - so treat the first real
+build as the thing to double-check, even though it mirrors exactly the
+`npm run build` commands already confirmed working locally for both
+projects.
 
 ## Project layout
 
@@ -150,6 +155,16 @@ For active development, `client`'s `npm run watch` rebuilds on save, and
 `tsx` (no separate compile step needed while iterating) - run both in
 separate terminals.
 
+Server tests (`server/test/*.test.ts`, Node's built-in test runner, no
+extra dependencies or compile step):
+
+```bash
+cd server && npm test
+```
+
+`server`'s `npm run typecheck` also covers `server/test/`, not just `src/`
+(see `tsconfig.test.json`).
+
 ## Deploying
 
 Build the Docker image from the **repo root** (it needs both `server/` and
@@ -184,6 +199,8 @@ Then put it behind your existing reverse proxy like everything else
 - [x] Full TypeScript rewrite (client + server), component-style client
       views (.ts/.html/.css each), server-side singleton services per
       feature — see docs/architecture.md
+- [x] Automated server test suite (`node:test`) + CI job gating the Docker
+      publish on typecheck+test+build passing — see docs/architecture.md
 - [ ] Try a full party end-to-end with two real accounts (still the main gap)
 - [ ] Tune transcoding target / support direct play when possible
 
diff --git a/docs/architecture.md b/docs/architecture.md
index f70b01b..548ab50 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -1057,16 +1057,36 @@ which `esbuild` would do even with type errors present, since it
 transpiles without checking; the client's own separate `tsc --noEmit`
 step is what actually guards against that gap.
 
-Server: every unit/integration test written earlier for the JS version
+Server: every unit/integration check written earlier for the JS version
 (party lifecycle logging, the music queue's timer/vote/pause behavior
 including real `setTimeout`-based auto-advance, the socket-level
 integration through `SocketGateway`+`PartyService`+`MusicQueueService`
 together, the library-type filter, the playback-override-forcing logic)
-was re-run against the **compiled** `server/dist` output, not the
-TypeScript source - every one passed unchanged (same assertions, same
-counts). The compiled server was also actually started (`node dist/index.js`)
-and confirmed listening cleanly, both directly and via `tsx` for the dev
-path.
+was first re-run ad hoc against the **compiled** `server/dist` output to
+confirm the port itself changed nothing behaviorally, then formalized
+into a real, committed suite: `server/test/*.test.ts` (one file per
+service - `musicQueueService`, `partyService`, `socketGateway`,
+`catalogService`), using Node's built-in `node:test` + `node:assert/strict`
+(zero new dependencies) and run straight against the TypeScript source via
+`tsx --test` (`npm test`) - no compile step, no separate test-runner
+dependency. A dedicated `tsconfig.test.json` (extends the base config,
+overrides `rootDir` to `.` and adds `test/**/*.ts` to `include`) lets
+`npm run typecheck` cover the test files too without pulling them into
+`dist/` when `npm run build` (plain `tsc`, still scoped to `src/`) runs.
+The compiled server was also actually started (`node dist/index.js`) and
+confirmed listening cleanly, both directly and via `tsx` for the dev path.
+
+### Continuous integration
+
+`.forgejo/workflows/publish-docker.yml` gained a `test` job that runs
+before `publish` (`needs: test`): server `npm run typecheck` + `npm test`,
+then client `npm run typecheck` + `npm run build`. It runs in a
+`node:20-alpine` container - a separate container from `publish`'s
+`docker:27-cli`, since that one has no Node at all (that's also why both
+jobs clone sources by hand with `git init`/`fetch`/`checkout` rather than
+`actions/checkout`, which is a JS action and needs Node to run). The two
+jobs don't share a filesystem, so each clones independently; `publish`
+only starts once `test` succeeds.
 
 Client: since esbuild bundles everything into one `app.js` (no more
 individually-importable view modules the way separate `<script
diff --git a/server/package.json b/server/package.json
index 8439aab..5453c17 100644
--- a/server/package.json
+++ b/server/package.json
@@ -8,7 +8,8 @@
     "build": "tsc",
     "start": "node dist/index.js",
     "dev": "tsx watch src/index.ts",
-    "typecheck": "tsc --noEmit"
+    "typecheck": "tsc -p tsconfig.test.json",
+    "test": "tsx --test test/**/*.test.ts"
   },
   "engines": {
     "node": ">=18"
diff --git a/server/test/catalogService.test.ts b/server/test/catalogService.test.ts
new file mode 100644
index 0000000..d60fe4f
--- /dev/null
+++ b/server/test/catalogService.test.ts
@@ -0,0 +1,89 @@
+// Exercises CatalogService's real logic (library-type filtering, the
+// audio/subtitle/quality override forcing) through its PUBLIC methods
+// against a mocked EmbyClient, not by calling private helpers directly.
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import type { Request, Response } from 'express';
+import { CatalogService } from '../src/services/CatalogService';
+import { EmbyClient } from '../src/emby/EmbyClient';
+import type { EmbySession } from '../src/types';
+
+const session: EmbySession = { embyToken: 'tok', userId: 'u1', userName: 'Alice', serverId: 'srv1', createdUtc: Date.now() };
+
+function jsonResponse(body: unknown): Response {
+  return new Response(JSON.stringify(body), { status: 200, headers: { 'Content-Type': 'application/json' } }) as unknown as Response;
+}
+
+function fakeReq(query: Record<string, string>): Request {
+  return { query, headers: {} } as unknown as Request;
+}
+
+function fakeRes(): Response {
+  return { status() { return this; }, json() {}, end() {} } as unknown as Response;
+}
+
+describe('CatalogService', () => {
+  it('getLibraries keeps only movies/tvshows/music/musicvideos out of everything /Views can return', async (t) => {
+    t.mock.method(EmbyClient, 'fetch', async () => jsonResponse({
+      Items: [
+        { Id: '1', Name: 'Films', CollectionType: 'movies' },
+        { Id: '2', Name: 'Series', CollectionType: 'tvshows' },
+        { Id: '3', Name: 'Musique', CollectionType: 'music' },
+        { Id: '4', Name: 'Clips', CollectionType: 'musicvideos' },
+        { Id: '5', Name: 'Photos', CollectionType: 'photos' },
+        { Id: '6', Name: 'Live TV', CollectionType: 'livetv' },
+        { Id: '7', Name: 'Collections', CollectionType: 'boxsets' },
+        { Id: '8', Name: 'No type at all' }
+      ]
+    }));
+
+    const libraries = await CatalogService.getLibraries(session);
+    assert.deepEqual(libraries.map((l) => l.name).sort(), ['Clips', 'Films', 'Musique', 'Series']);
+  });
+
+  it('proxyStream forces a subtitle pick (and SubtitleMethod=Encode) onto a negotiated TranscodingUrl', async (t) => {
+    t.mock.method(EmbyClient, 'fetch', async () => jsonResponse({
+      MediaSources: [{ Id: 'src1', TranscodingUrl: '/videos/item1/master.m3u8?MediaSourceId=src1&AudioStreamIndex=1' }],
+      PlaySessionId: 'sess1'
+    }));
+    let capturedTarget = '';
+    t.mock.method(EmbyClient, 'proxyResponse', async (_req: Request, _res: Response, target: string) => { capturedTarget = target; });
+
+    await CatalogService.proxyStream(fakeReq({ SubtitleStreamIndex: '3', AudioStreamIndex: '2' }), fakeRes(), session, 'item1');
+
+    assert.ok(capturedTarget.includes('SubtitleStreamIndex=3'));
+    assert.ok(capturedTarget.includes('SubtitleMethod=Encode'));
+    assert.ok(capturedTarget.includes('AudioStreamIndex=2'));
+  });
+
+  it('proxyStream\'s hand-built fallback picks /Audio/ (and drops VideoCodec) for a music track', async (t) => {
+    t.mock.method(EmbyClient, 'fetch', async () => jsonResponse({ MediaSources: [{ Id: 'src2' }], PlaySessionId: 'sess2' }));
+    let capturedTarget = '';
+    t.mock.method(EmbyClient, 'proxyResponse', async (_req: Request, _res: Response, target: string) => { capturedTarget = target; });
+
+    await CatalogService.proxyStream(fakeReq({ mediaType: 'audio' }), fakeRes(), session, 'track1');
+
+    assert.ok(capturedTarget.startsWith('/Audio/track1/master.m3u8'));
+    assert.ok(!capturedTarget.includes('VideoCodec'));
+  });
+
+  it('proxyStream\'s hand-built fallback picks /Videos/ (with VideoCodec) for anything else', async (t) => {
+    t.mock.method(EmbyClient, 'fetch', async () => jsonResponse({ MediaSources: [{ Id: 'src3' }], PlaySessionId: 'sess3' }));
+    let capturedTarget = '';
+    t.mock.method(EmbyClient, 'proxyResponse', async (_req: Request, _res: Response, target: string) => { capturedTarget = target; });
+
+    await CatalogService.proxyStream(fakeReq({}), fakeRes(), session, 'movie1');
+
+    assert.ok(capturedTarget.startsWith('/Videos/movie1/master.m3u8'));
+    assert.ok(capturedTarget.includes('VideoCodec=h264'));
+  });
+
+  it('getRawItem preserves Emby\'s own status (a real 404), not a blanket 502', async (t) => {
+    t.mock.method(EmbyClient, 'fetch', async () => new Response(null, { status: 404 }) as unknown as Response);
+
+    await assert.rejects(
+      () => CatalogService.getRawItem(session, 'missing'),
+      (err: Error & { status?: number }) => err.status === 404
+    );
+  });
+});
diff --git a/server/test/musicQueueService.test.ts b/server/test/musicQueueService.test.ts
new file mode 100644
index 0000000..9a7a1ec
--- /dev/null
+++ b/server/test/musicQueueService.test.ts
@@ -0,0 +1,113 @@
+// Exercises MusicQueueService directly against fake parties - no Express/
+// session/Emby involved. Covers the intricate bits: auto-start on first
+// add, server-authoritative auto-advance via a real timer, pause/resume
+// elapsed-time math, majority vote-skip, and - given how strongly memory
+// leaks have mattered throughout this project (see docs/architecture.md) -
+// that the advance timer is ALWAYS cleared (never left dangling) on skip,
+// on destroy, and is never double-scheduled.
+import { describe, it, mock } from 'node:test';
+import assert from 'node:assert/strict';
+import { setTimeout as sleep } from 'node:timers/promises';
+import { MusicQueueService } from '../src/services/MusicQueueService';
+import type { MusicState, Party } from '../src/types';
+
+function fakeParty(id: string): Party {
+  return {
+    id,
+    mediaType: 'music',
+    itemId: '',
+    itemName: '',
+    itemImageUrl: '',
+    queue: [],
+    queueIndex: 0,
+    hostUserId: 'u-alice',
+    createdUtc: Date.now(),
+    lastActivityUtc: Date.now(),
+    members: new Map()
+  };
+}
+
+function music(party: Party): MusicState {
+  return party.music as MusicState;
+}
+
+describe('MusicQueueService', () => {
+  it('init() auto-starts the first track and mirrors it onto party.itemName', () => {
+    const party = fakeParty('p1');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 10_000_000 }, 'u-alice', 'Alice');
+
+    assert.equal(music(party).current?.track.itemId, 't1');
+    assert.equal(music(party).queue.length, 0);
+    assert.equal(party.itemName, 'Track One');
+  });
+
+  it('adding a track while one plays queues it instead of jumping the gun', () => {
+    const party = fakeParty('p2');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 10_000_000 }, 'u-alice', 'Alice');
+    MusicQueueService.addTrack(party, { itemId: 't2', itemName: 'Track Two', itemImageUrl: '/img/t2', durationTicks: 30_000_000 }, 'u-bob', 'Bob');
+
+    assert.equal(music(party).current?.track.itemId, 't1');
+    assert.equal(music(party).queue.length, 1);
+  });
+
+  it('voteSkip needs a strict majority of connected members, not any count', () => {
+    const party = fakeParty('p3');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 10_000_000 }, 'u-alice', 'Alice');
+    MusicQueueService.addTrack(party, { itemId: 't2', itemName: 'Track Two', itemImageUrl: '/img/t2', durationTicks: 30_000_000 }, 'u-bob', 'Bob');
+
+    assert.equal(MusicQueueService.voteSkip(party, 'u-alice', 'Alice', 2), false, 'one of two needed should not skip yet');
+    assert.equal(music(party).current?.track.itemId, 't1');
+
+    assert.equal(MusicQueueService.voteSkip(party, 'u-bob', 'Bob', 2), true, 'the second vote should reach the majority');
+    assert.equal(music(party).current?.track.itemId, 't2');
+    assert.equal(music(party).skipVotes.size, 0, 'skipping clears the tally for the new track');
+  });
+
+  it('pause freezes elapsed time; resume continues it from where it froze', async () => {
+    const party = fakeParty('p4');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 600_000_000 }, 'u-alice', 'Alice');
+
+    MusicQueueService.setPaused(party, true);
+    assert.equal(music(party).current?.isPaused, true);
+    const frozen = MusicQueueService.getElapsedSeconds(party);
+    await sleep(50);
+    assert.equal(MusicQueueService.getElapsedSeconds(party), frozen, 'time must not advance while paused');
+
+    MusicQueueService.setPaused(party, false);
+    assert.equal(music(party).current?.isPaused, false);
+    await sleep(50);
+    assert.ok(MusicQueueService.getElapsedSeconds(party) >= frozen, 'time should advance again after resuming');
+
+    MusicQueueService.destroy(party); // avoid leaking this test's own long-duration timer
+  });
+
+  it('a short track auto-advances on its own via a real timer, with no client reporting "ended"', async () => {
+    const party = fakeParty('p5');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 10_000_000 /* 1s */ }, 'u-alice', 'Alice');
+
+    assert.notEqual(music(party).advanceTimer, null, 'a timer should be scheduled for the auto-advance');
+    await sleep(1300); // a bit over the 1s duration
+    assert.equal(music(party).current, null, 'nothing queued behind it, so current should now be empty');
+  });
+
+  it('destroy() clears a pending timer - the actual leak-prevention path', (t) => {
+    const realClearTimeout = global.clearTimeout;
+    const cleared = mock.fn(realClearTimeout);
+    global.clearTimeout = cleared as typeof clearTimeout;
+    t.after(() => { global.clearTimeout = realClearTimeout; });
+
+    const party = fakeParty('p6');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 600_000_000 /* 60s - stays pending */ }, 'u-alice', 'Alice');
+    assert.notEqual(music(party).advanceTimer, null);
+
+    MusicQueueService.destroy(party);
+    assert.equal(cleared.mock.callCount(), 1, 'clearTimeout should have been called exactly once');
+    assert.equal(music(party).advanceTimer, null);
+  });
+
+  it('removeVote() is a harmless no-op for a party with no music state at all', () => {
+    const videoParty: Party = { ...fakeParty('p7'), mediaType: 'video' };
+    delete videoParty.music;
+    assert.doesNotThrow(() => MusicQueueService.removeVote(videoParty, 'u-anyone'));
+  });
+});
diff --git a/server/test/partyService.test.ts b/server/test/partyService.test.ts
new file mode 100644
index 0000000..ed5bf11
--- /dev/null
+++ b/server/test/partyService.test.ts
@@ -0,0 +1,70 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { PartyService } from '../src/services/PartyService';
+
+describe('PartyService', () => {
+  it('create() sets mediaType and seeds the host as the first member', () => {
+    const party = PartyService.create('u-alice', 'Alice', 'ep1', 'S01E01 - Pilote', '/img/ep1', [
+      { itemId: 'ep1', itemName: 'S01E01 - Pilote', itemImageUrl: '/img/ep1' },
+      { itemId: 'ep2', itemName: 'S01E02 - Suite', itemImageUrl: '/img/ep2' }
+    ], 'video');
+
+    assert.equal(party.mediaType, 'video');
+    assert.equal(party.members.size, 1);
+    assert.equal(party.hostUserId, 'u-alice');
+  });
+
+  it('advanceQueue moves through the fixed queue and stops at the end', () => {
+    const party = PartyService.create('u-alice', 'Alice', 'ep1', 'S01E01', '/img/ep1', [
+      { itemId: 'ep1', itemName: 'S01E01', itemImageUrl: '/img/ep1' },
+      { itemId: 'ep2', itemName: 'S01E02', itemImageUrl: '/img/ep2' }
+    ], 'video');
+
+    assert.equal(PartyService.advanceQueue(party), true);
+    assert.equal(party.itemId, 'ep2');
+    assert.equal(PartyService.advanceQueue(party), false, 'nothing left after the last item');
+  });
+
+  it('leave(): a non-host leaving neither destroys the party nor hands off', () => {
+    const party = PartyService.create('u-alice', 'Alice', 'm1', 'Un Film', '/img/m1', null, 'video');
+    PartyService.join(party, 'u-bob', 'Bob');
+
+    const result = PartyService.leave(party, 'u-bob');
+    assert.equal(result.destroyed, false);
+    assert.equal(result.hostChanged, false);
+  });
+
+  it('leave(): the host leaving with someone left hands off, and party.hostUserId actually updates', () => {
+    const party = PartyService.create('u-alice', 'Alice', 'm1', 'Un Film', '/img/m1', null, 'video');
+    PartyService.join(party, 'u-bob', 'Bob');
+
+    const result = PartyService.leave(party, 'u-alice');
+    assert.equal(result.hostChanged, true);
+    assert.equal(result.newHostUserId, 'u-bob');
+    assert.equal(party.hostUserId, 'u-bob');
+  });
+
+  it('leave(): the last member leaving destroys the party', () => {
+    const party = PartyService.create('u-alice', 'Alice', 'm1', 'Un Film', '/img/m1', null, 'video');
+
+    const result = PartyService.leave(party, 'u-alice');
+    assert.equal(result.destroyed, true);
+    assert.equal(PartyService.getById(party.id), null);
+  });
+
+  it('removeIdleParties sweeps a party whose lastActivityUtc is past the cutoff', () => {
+    const party = PartyService.create('u-dave', 'Dave', 'm1', 'Un Film', '/img/m1', null, 'video');
+    party.lastActivityUtc = Date.now() - 5 * 60 * 60 * 1000;
+
+    PartyService.removeIdleParties(4 * 60 * 60 * 1000);
+    assert.equal(PartyService.getById(party.id), null);
+  });
+
+  it('toPublicState reports youAreHost for the creator, and music:null for a video party', () => {
+    const party = PartyService.create('u-eve', 'Eve', 'm2', 'Un Autre Film', '/img/m2', null, 'video');
+    const state = PartyService.toPublicState(party, 'u-eve');
+
+    assert.equal(state.youAreHost, true);
+    assert.equal(state.music, null);
+  });
+});
diff --git a/server/test/socketGateway.test.ts b/server/test/socketGateway.test.ts
new file mode 100644
index 0000000..42d56cd
--- /dev/null
+++ b/server/test/socketGateway.test.ts
@@ -0,0 +1,184 @@
+// End-to-end checks of the realtime protocol through the REAL
+// SocketGateway + PartyService + MusicQueueService together (not just one
+// service in isolation) - a fake io/socket pair standing in for Socket.IO
+// itself, since a real client<->server round trip needs an actual HTTP
+// upgrade.
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { PartyService } from '../src/services/PartyService';
+import { MusicQueueService } from '../src/services/MusicQueueService';
+import { SocketGateway } from '../src/realtime/SocketGateway';
+import type { AppServer, AppSocket } from '../src/types';
+
+type Handler = (payload?: unknown) => void;
+
+function fakeSocket(cookie: string) {
+  const handlers = new Map<string, Handler[]>();
+  const emitted: [string, unknown][] = [];
+  return {
+    request: { headers: { cookie } },
+    emitted,
+    on(event: string, cb: Handler) {
+      const list = handlers.get(event) || [];
+      list.push(cb);
+      handlers.set(event, list);
+    },
+    emit(event: string, payload?: unknown) { emitted.push([event, payload]); },
+    to() { return { emit() {} }; },
+    join() {},
+    disconnect() {},
+    trigger(event: string, payload?: unknown) { (handlers.get(event) || []).forEach((cb) => cb(payload)); }
+  };
+}
+
+function fakeIo() {
+  const handlers = new Map<string, ((...args: unknown[]) => void)[]>();
+  const roomEmits: { room: string; event: string; payload: unknown }[] = [];
+  return {
+    roomEmits,
+    on(event: string, cb: (...args: unknown[]) => void) {
+      const list = handlers.get(event) || [];
+      list.push(cb);
+      handlers.set(event, list);
+    },
+    to(room: string) { return { emit: (event: string, payload: unknown) => roomEmits.push({ room, event, payload }) }; },
+    trigger(event: string, ...args: unknown[]) { (handlers.get(event) || []).forEach((cb) => cb(...args)); }
+  };
+}
+
+function attach(io: ReturnType<typeof fakeIo>) {
+  SocketGateway.attach(
+    io as unknown as AppServer,
+    (raw) => ({ wp_session: raw as string }),
+    (sessionId) => ({ userId: sessionId, userName: sessionId })
+  );
+  MusicQueueService.attachIo(io as unknown as AppServer, () => {});
+}
+
+describe('SocketGateway', () => {
+  it('voteSkip/musicPlaystate are no-ops on a video party', () => {
+    const io = fakeIo();
+    attach(io);
+    const party = PartyService.create('u-host', 'Host', 'm1', 'Un Film', '/img/m1', null, 'video');
+    const socket = fakeSocket('u-host');
+    io.trigger('connection', socket as unknown as AppSocket);
+    socket.trigger('join', { partyId: party.id });
+
+    const before = io.roomEmits.length;
+    socket.trigger('voteSkip');
+    socket.trigger('musicPlaystate', { isPaused: true });
+    assert.equal(io.roomEmits.length, before, 'neither event should produce any broadcast on a video party');
+  });
+
+  it('a non-host member can pause and resume a music party directly (no host check)', () => {
+    const io = fakeIo();
+    attach(io);
+    const party = PartyService.create('u-alice', 'Alice', 't1', 'Track One', '/img/t1', null, 'music');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 10_000_000 }, 'u-alice', 'Alice');
+    PartyService.join(party, 'u-bob', 'Bob');
+
+    const bobSocket = fakeSocket('u-bob');
+    io.trigger('connection', bobSocket as unknown as AppSocket);
+    bobSocket.trigger('join', { partyId: party.id });
+
+    assert.notEqual(party.hostUserId, 'u-bob');
+    bobSocket.trigger('musicPlaystate', { isPaused: true });
+    assert.equal(party.music?.current?.isPaused, true);
+    bobSocket.trigger('musicPlaystate', { isPaused: false });
+    assert.equal(party.music?.current?.isPaused, false);
+  });
+
+  it('voteSkip needs a majority of connected members and broadcasts queueUpdated on the party room', () => {
+    const io = fakeIo();
+    attach(io);
+    const party = PartyService.create('u-alice', 'Alice', 't1', 'Track One', '/img/t1', null, 'music');
+    MusicQueueService.init(party, { itemId: 't1', itemName: 'Track One', itemImageUrl: '/img/t1', durationTicks: 10_000_000 }, 'u-alice', 'Alice');
+    PartyService.join(party, 'u-bob', 'Bob');
+
+    const aliceSocket = fakeSocket('u-alice');
+    io.trigger('connection', aliceSocket as unknown as AppSocket);
+    aliceSocket.trigger('join', { partyId: party.id });
+    const bobSocket = fakeSocket('u-bob');
+    io.trigger('connection', bobSocket as unknown as AppSocket);
+    bobSocket.trigger('join', { partyId: party.id });
+
+    bobSocket.trigger('voteSkip');
+    assert.equal(party.music?.current?.track.itemId, 't1', 'one of two connected should not skip yet');
+
+    io.roomEmits.length = 0;
+    aliceSocket.trigger('voteSkip');
+    assert.equal(party.music?.current, null, 'the second vote reaches the majority (no second track queued)');
+    assert.ok(io.roomEmits.some((e) => e.room === party.id && e.event === 'queueUpdated'));
+  });
+
+  it('leaving hands the host off live and refreshes the lobby', () => {
+    const io = fakeIo();
+    attach(io);
+    const party = PartyService.create('u-alice', 'Alice', 'm1', 'Un Film', '/img/m1', null, 'video');
+    PartyService.join(party, 'u-bob', 'Bob');
+    const bobSocket = fakeSocket('u-bob');
+    io.trigger('connection', bobSocket as unknown as AppSocket);
+    bobSocket.trigger('join', { partyId: party.id });
+
+    const aliceSocket = fakeSocket('u-alice');
+    io.trigger('connection', aliceSocket as unknown as AppSocket);
+    aliceSocket.trigger('join', { partyId: party.id });
+    aliceSocket.trigger('disconnect');
+
+    assert.equal(party.hostUserId, 'u-bob');
+    assert.ok(bobSocket.emitted.some(([event]) => event === 'hostChanged'), 'the new host should get a personal notification');
+  });
+
+  it('playstate logs only on an actual pause/play transition, never on an unchanged heartbeat resend', (t) => {
+    const logged: string[] = [];
+    t.mock.method(console, 'log', (line: string) => { logged.push(line); });
+
+    const io = fakeIo();
+    attach(io);
+    const party = PartyService.create('u-alice', 'Alice', 'm1', 'Un Film', '/img/m1', null, 'video');
+    const socket = fakeSocket('u-alice');
+    io.trigger('connection', socket as unknown as AppSocket);
+    socket.trigger('join', { partyId: party.id });
+
+    const playstateLines = () => logged.filter((l) => l.includes(' playstate '));
+
+    // The initial state is a real transition (a new member defaults to
+    // isPaused:true - see PartyService's newMember) - this is "the party
+    // started playing", and should log.
+    socket.trigger('playstate', { isPaused: false, positionTicks: 10_000_000 });
+    assert.equal(playstateLines().length, 1);
+
+    // 5 heartbeats, same isPaused, only position moving - none of these
+    // should add a line (the player re-sends its current state every 3s
+    // regardless of whether anything changed - see docs/architecture.md).
+    for (let i = 0; i < 5; i++) socket.trigger('playstate', { isPaused: false, positionTicks: 10_000_000 + i * 30_000_000 });
+    assert.equal(playstateLines().length, 1);
+
+    socket.trigger('playstate', { isPaused: true, positionTicks: 160_000_000 });
+    assert.equal(playstateLines().length, 2);
+
+    for (let i = 0; i < 3; i++) socket.trigger('playstate', { isPaused: true, positionTicks: 160_000_000 });
+    assert.equal(playstateLines().length, 2);
+
+    socket.trigger('playstate', { isPaused: false, positionTicks: 160_000_000 });
+    assert.equal(playstateLines().length, 3);
+  });
+
+  it('requestPause is throttled per member (5s) even against a raw repeat', (t) => {
+    const logged: string[] = [];
+    t.mock.method(console, 'log', (line: string) => { logged.push(line); });
+
+    const io = fakeIo();
+    attach(io);
+    const party = PartyService.create('u-alice', 'Alice', 'm1', 'Un Film', '/img/m1', null, 'video');
+    PartyService.join(party, 'u-bob', 'Bob');
+    const bobSocket = fakeSocket('u-bob');
+    io.trigger('connection', bobSocket as unknown as AppSocket);
+    bobSocket.trigger('join', { partyId: party.id });
+
+    bobSocket.trigger('requestPause');
+    bobSocket.trigger('requestPause');
+    const pauseRequestLines = logged.filter((l) => l.includes(' pauseRequested '));
+    assert.equal(pauseRequestLines.length, 1, 'an immediate repeat must not produce a second line');
+  });
+});
diff --git a/server/tsconfig.test.json b/server/tsconfig.test.json
new file mode 100644
index 0000000..c8c5ea7
--- /dev/null
+++ b/server/tsconfig.test.json
@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "rootDir": ".",
+    "noEmit": true
+  },
+  "include": ["src/**/*.ts", "test/**/*.ts"]
+}