Function testBlockWaitsForDrain

test/parallel/test-stream-iter-writable-interop.js:87–106

()

// =============================================================================

async function testBlockWaitsForDrain() {
  const chunks = [];
  const writable = new Writable({
    highWaterMark: 1,  // Very small buffer
    write(chunk, encoding, cb) {
      chunks.push(Buffer.from(chunk));
      // Delay callback to simulate slow consumer
      setTimeout(cb, 10);
    },
  });

  const writer = fromWritable(writable, { backpressure: 'block' });

  await writer.write('a');
  await writer.write('b');
  await writer.write('c');
  await writer.end();

  assert.strictEqual(Buffer.concat(chunks).toString(), 'abc');
}

// =============================================================================
// block: stream error rejects pending write