Fix lack of Tachyon message validation in client

Unfortunatelly JSON.parse returns `any` not `unknown` so type
checking didn't caought this mistake.

src/tachyonClient.test.ts

@@ -5,7 +5,7 @@ import { once } from 'node:events';
 import { TachyonClient } from './tachyonClient.js';
 import { createTachyonServer } from './tachyonServer.fake.js';
 import { deepEqual } from 'node:assert';
-import { TachyonMessage } from './tachyonTypes.js';
+import { TachyonMessage, TachyonResponseOk } from './tachyonTypes.js';
 
 // Let's reuse the same server for all tests to make them quicker.
 const server = await createTachyonServer({ clientId: 'c', clientSecret: 's' });
@@ -14,6 +14,13 @@ const port = server.fastifyServer.addresses()[0].port;
 after(() => server.close());
 afterEach(() => server.removeAllListeners());
 
+const connectionParams = {
+	clientId: 'c',
+	clientSecret: 's',
+	hostname: 'localhost',
+	port,
+};
+
 test('simple full example', async () => {
 	server.on('connection', (conn) => {
 		conn.on('message', (msg) => {
@@ -29,12 +36,7 @@ test('simple full example', async () => {
 		});
 	});
 
-	const client = new TachyonClient({
-		clientId: 'c',
-		clientSecret: 's',
-		hostname: 'localhost',
-		port,
-	});
+	const client = new TachyonClient(connectionParams);
 	await once(client, 'connected');
 	client.send({
 		type: 'request',
@@ -52,4 +54,28 @@ test('simple full example', async () => {
 	client.close();
 });
 
+test("doesn't emit bad tachyon messages", async () => {
+	server.on('connection', (conn) => {
+		conn.on('message', () => {
+			conn.send({
+				type: 'asdasdasd',
+			} as unknown as TachyonResponseOk);
+		});
+	});
+	const client = new TachyonClient(connectionParams);
+	await once(client, 'connected');
+	client.send({
+		type: 'request',
+		commandId: 'test/command',
+		messageId: 'test-message1',
+		data: { test: 'test' },
+	});
+	let gotMessages = 0;
+	client.on('message', () => {
+		++gotMessages;
+	});
+	await once(client, 'close');
+	equal(gotMessages, 0);
+});
+
 // TODO: Add more tests then only a simple happy path.

src/tachyonClient.ts

@@ -6,7 +6,7 @@
  * and the client can send messages to the server.
  */
 import { TypedEmitter } from 'tiny-typed-emitter';
-import { TachyonMessage, TACHYON_PROTOCOL_VERSION } from './tachyonTypes.js';
+import { parseTachyonMessage, TachyonMessage, TACHYON_PROTOCOL_VERSION } from './tachyonTypes.js';
 import { getAccessToken } from './oauth2Client.js';
 import WebSocket from 'ws';
 
@@ -95,14 +95,15 @@ export class TachyonClient extends TypedEmitter<{
 				this.close();
 				return;
 			}
+			let tachyonMsg: TachyonMessage;
 			try {
-				const tachyonMsg = JSON.parse(msg.toString('utf-8'));
-				this.emit('message', tachyonMsg);
+				tachyonMsg = parseTachyonMessage(msg.toString('utf-8'));
 			} catch (e) {
 				ws.close(1008, 'Failed to parse base tachyon message');
 				this.close();
 				return;
 			}
+			this.emit('message', tachyonMsg);
 		});
 	}