Resolve #20: Na katex-server čekáme pomocí stdoutu.

src/formatitko/katex-server/index.mjs

@@ -41,6 +41,7 @@ if (!unixSocketPath) {
 // This server listens on a Unix socket at /var/run/mysocket
 var unixServer = net.createServer(handleClient);
 unixServer.listen(unixSocketPath);
+console.log("OK")
 
 function handleExit(signal) {
     // unixServer.emit('close')

src/formatitko/katex.py

@@ -28,22 +28,16 @@ class KatexClient:
 					raise Exception("npm not found. Node.js is required to use KaTeX.")
 				else:
 					raise e
-		self._server_process = subprocess.Popen(["node", srcdir + "/katex-server/index.mjs", self._socket_file])
 
-		self._client = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+		self._server_process = subprocess.Popen(["node", srcdir + "/katex-server/index.mjs", self._socket_file], stdout=subprocess.PIPE)
 
-		# Wait for the node program to create the socket file
-		while not os.path.exists(self._socket_file):
-			time.sleep(0.01)
+		self._client = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+		
+		ok = self._server_process.stdout.readline()
+		if ok != b"OK\n":
+			raise Exception("Failed to connect to katex-server")
 
-		# Wait for the node program to start accepting connections
-		while True:
-			try:
-				self._client.connect(self._socket_file)
-				time.sleep(0.01)
-			except ConnectionRefusedError:
-				continue
-			break
+		self._client.connect(self._socket_file)
 
 	def render(self, tex: str, options: Dict={}):
 		# Send formulas to translate