deno-websocket-example.ts

const decoder = new TextDecoder('utf-8');
let text:string;
let lines:string[];
try {
  text = decoder.decode(await Deno.readFile("./test.txt"))
  lines = text.split("\n")
} catch(e) {
  console.error(e)
  Deno.exit(1)
}

// Start the connection to the WebSocket server at echo.websocket.org
const ws = new WebSocket("ws://echo.websocket.org/");

// Register event listeners for the open, close, and message events
ws.onopen = () => {
  console.log("WebSocket ready!");

  lines.forEach( (l:string) => {
    console.log(l)
    ws.send(l)
  } )
};
ws.onmessage = (message) => {
  // Log the message we recieve:
  console.log("Received data:", message.data);

  // Close the websocket after receiving the "exit" message (the last line)
  if(message.data == "exit") ws.close();
};

ws.onclose = () => console.log("WebSocket closed!");
ws.onerror = (err) => console.log("WebSocket error:", err);