MC Chat Filtering

const express = require('express'),
  app = express();

const badWordFilter = ["herobrine", "blobs"];

app.use(express.json());

/*
  {
    "response": // Boolean - If this is true it goes to "passThrough" (Not filtered!)
    "hashed": // String - If not present, it gets fully filtered (removed) - if this is here then `hashes` is required!
    "hashes": // Json Array - The bad words found
  }
 */

app.all('/*', (req, res, next) => {
  console.log(`${req.ip} ${req.method} ${req.originalUrl}`);
  console.log(req.headers);
  console.log(req.body);

  next();
});

app.post('/v1/join', (req, res) => {
  res.status(200).json({
    response: true
  })
});

app.post('/v1/leave', (req, res) => {
  res.status(200).json({
    response: true
  })
});

app.post('/v1/chat', (req, res) => {
  const body = req.body;

  // Notch is exempt from the chat filter!
  if (body.player_display_name === 'Notch') {
    return res.status(200).json({ response: true });
  }

  const text = body.text.toLowerCase();
  let filteredText = text;

  const badWords = [];

  for (badWord of badWordFilter) {
    if (text.includes(badWord)) {
      badWords.push(badWord);

      filteredText = filteredText.replace(badWord, '*'.repeat(badWord.length));
    }
  }

  // There's a bad word
  if (badWords.length > 0) {
    res.status(200).json({
      response: false,
      hashed: filteredText,
      hashes: badWords
    })
  } else {
    // No filtering needed
    res.status(200).json({
      response: true
    })
  }
});

app.listen(8000, () => console.log('Listening on :8000'));