feat(vela): support end-to-end mocked turn cancelation

apps/vela-gateway/src/index.js

@@ -22,7 +22,8 @@ function createSessionRecord() {
 		audioChunkCount: 0,
 		started: false,
 		mockedTurnInFlight: false,
-		mockedTurnTimers: []
+		mockedTurnTimers: [],
+		activeMockedTurnId: null
 	};
 }
 
@@ -33,11 +34,17 @@ function clearMockedTurn(session) {
 
 	session.mockedTurnTimers = [];
 	session.mockedTurnInFlight = false;
+	session.activeMockedTurnId = null;
 }
 
-function scheduleMockedTurnStep(session, delay, callback) {
+function scheduleMockedTurnStep(session, turnId, delay, callback) {
 	const timer = setTimeout(() => {
 		session.mockedTurnTimers = session.mockedTurnTimers.filter((activeTimer) => activeTimer !== timer);
+
+		if (!session.mockedTurnInFlight || session.activeMockedTurnId !== turnId) {
+			return;
+		}
+
 		callback();
 	}, delay);
 
@@ -53,23 +60,25 @@ function startMockedTurn(socket, session) {
 	clearMockedTurn(session);
 	session.audioChunkCount = 0;
 	session.mockedTurnInFlight = true;
+	const turnId = crypto.randomUUID();
+	session.activeMockedTurnId = turnId;
 	updateSessionState(socket, session, 'listening');
 
-	scheduleMockedTurnStep(session, 75, () => {
+	scheduleMockedTurnStep(session, turnId, 75, () => {
 		sendSocketMessage(socket, 'transcript.final', { text: MOCKED_USER_TRANSCRIPT });
 		updateSessionState(socket, session, 'thinking');
 	});
 
-	scheduleMockedTurnStep(session, 150, () => {
+	scheduleMockedTurnStep(session, turnId, 150, () => {
 		updateSessionState(socket, session, 'speaking');
 		sendSocketMessage(socket, 'response.text.delta', { text: '[mocked assistant] ' });
 	});
 
-	scheduleMockedTurnStep(session, 225, () => {
+	scheduleMockedTurnStep(session, turnId, 225, () => {
 		sendSocketMessage(socket, 'response.text.delta', { text: MOCKED_ASSISTANT_RESPONSE.replace('[mocked assistant] ', '') });
 	});
 
-	scheduleMockedTurnStep(session, 300, () => {
+	scheduleMockedTurnStep(session, turnId, 300, () => {
 		sendSocketMessage(socket, 'response.completed', {});
 		clearMockedTurn(session);
 		updateSessionState(socket, session, 'idle');

apps/vela-gateway/test/websocket-session.test.js

@@ -405,3 +405,67 @@ test('websocket rejects a second mocked turn while one is in flight', async () =
 		await server.close();
 	}
 });
+
+test('websocket cancel stops an active mocked turn and allows a new one without reconnecting', async () => {
+	const server = await startServer();
+
+	try {
+		const client = await connectWebSocket(server.port);
+		await client.nextMessage();
+		await client.nextMessage();
+
+		client.sendJson({ type: 'mocked.turn.trigger', payload: {} });
+		assert.deepEqual(await client.nextMessage(), {
+			type: 'session.state',
+			payload: { value: 'listening' }
+		});
+		assert.deepEqual(await client.nextMessage(), {
+			type: 'transcript.final',
+			payload: { text: '[mocked user] What is the current mocked vertical slice?' }
+		});
+		assert.deepEqual(await client.nextMessage(), {
+			type: 'session.state',
+			payload: { value: 'thinking' }
+		});
+
+		client.sendJson({ type: 'response.cancel', payload: {} });
+		assert.deepEqual(await client.nextMessage(), {
+			type: 'session.state',
+			payload: { value: 'idle' }
+		});
+		await assert.rejects(() => client.nextMessage(150), /timed out waiting for websocket message/);
+
+		client.sendJson({ type: 'mocked.turn.trigger', payload: {} });
+		assert.deepEqual(await client.nextMessage(), {
+			type: 'session.state',
+			payload: { value: 'listening' }
+		});
+
+		await client.close();
+	} finally {
+		await server.close();
+	}
+});
+
+test('websocket safely accepts cancel when no turn is active', async () => {
+	const server = await startServer();
+
+	try {
+		const client = await connectWebSocket(server.port);
+		await client.nextMessage();
+		await client.nextMessage();
+
+		client.sendJson({ type: 'response.cancel', payload: {} });
+		await assert.rejects(() => client.nextMessage(150), /timed out waiting for websocket message/);
+
+		client.sendJson({ type: 'mocked.turn.trigger', payload: {} });
+		assert.deepEqual(await client.nextMessage(), {
+			type: 'session.state',
+			payload: { value: 'listening' }
+		});
+
+		await client.close();
+	} finally {
+		await server.close();
+	}
+});