How to fix Error: Cannot resume stream that is still reading (pause/resume mismatch) in Node.js

let isPaused = false;

readable.on('data', (chunk) => {
  // Process chunk
  if (shouldPause) {
    readable.pause();
    isPaused = true;
  }
});

readable.on('drain', () => {
  if (isPaused) {
    readable.resume();
    isPaused = false;
  }
});

const readable = fs.createReadStream('input.txt');
const writable = fs.createWriteStream('output.txt');

readable.on('data', (chunk) => {
  const canContinue = writable.write(chunk);

  if (!canContinue) {
    // Backpressure: destination buffer is full
    readable.pause();
  }
});

writable.on('drain', () => {
  // Destination buffer is drained, resume reading
  readable.resume();
});

const fs = require('fs');
const readable = fs.createReadStream('input.txt');
const writable = fs.createWriteStream('output.txt');

// pipe() handles pause/resume automatically
readable.pipe(writable);

readable.on('error', (err) => console.error('Read error:', err));
writable.on('error', (err) => console.error('Write error:', err));

const readable = fs.createReadStream('file.txt');

// Wrong: resume() on a stream that was never paused
readable.resume(); // ❌ May cause mismatch error

// Correct: only resume after pause
readable.pause();
readable.resume(); // ✓ OK

// Or check the stream state
if (!readable.readableFlowing) {
  readable.resume(); // Safe: stream is paused
}

const readable = fs.createReadStream('input.txt');
const writable = fs.createWriteStream('output.txt');

// Piped streams handle pause/resume internally
readable.pipe(writable);

// If you need to pause, unpipe first:
function pauseReading() {
  readable.unpipe(writable);
  readable.pause();
}

function resumeReading() {
  readable.resume();
  readable.pipe(writable); // Re-establish pipe
}

const readable = fs.createReadStream('file.txt');

console.log('Initial readableFlowing:', readable.readableFlowing); // null (paused mode)

readable.on('data', () => {
  console.log('readableFlowing:', readable.readableFlowing); // true (flowing mode)
});

readable.pause();
console.log('After pause, readableFlowing:', readable.readableFlowing); // false

readable.resume();
console.log('After resume, readableFlowing:', readable.readableFlowing); // true