Incorrect Event loop callbacks execution order in a node.js project

[zveroboy]

Describe the bug

nextTick callbacks should be executed between macrotasks.

…the nextTickQueue will be processed after the current operation is completed, regardless of the current phase of the event loop. Here, an operation is defined as a transition from the underlying C/C++ handler, and handling the JavaScript that needs to be executed.

source

Immediately after every macrotask, the engine executes all tasks from microtask queue, prior to running any other macrotasks…

source

Link to the blitz that caused the error

https://stackblitz.com/edit/node-u4nbwx?file=index.js

Steps to reproduce

1. Launch node.js project
2. Put this code in the index.js

setTimeout(() => {
  console.log('--- Timer 1 ---');
  process.nextTick(() => {
    console.log('--- nextTick 1 ---');
  });
}, 0);

setTimeout(() => {
  console.log('--- Timer 2 ---');
  process.nextTick(() => {
    console.log('--- nextTick 2 ---');
  });
}, 0);

setImmediate(() => {
  console.log('--- setImmediate 1 ---');
});

3. Run node index.js in the terminal
4. You'll see incorrect execution order

~/projects/node-u4nbwx
❯ node index
--- setImmediate 1 ---
--- Timer 1 ---
--- Timer 2 ---
--- nextTick 1 ---
--- nextTick 2 ---

Expected behavior

It should print out

--- Timer 1 ---
--- nextTick 1 ---
--- Timer 2 ---
--- nextTick 2 ---
--- setImmediate 1 ---

or

--- setImmediate 1 ---
--- Timer 1 ---
--- nextTick 1 ---
--- Timer 2 ---
--- nextTick 2 ---

Parity with Local

• I have run the project in my local machine and I could not reproduce the issue.

Screenshots

Platform

Browser name  = Chrome
Full version  = 112.0.0.0
Major version = 112
navigator.appName = Netscape
navigator.userAgent = Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36
performance.memory = {
  "totalJSHeapSize": 63087190,
  "usedJSHeapSize": 58269934,
  "jsHeapSizeLimit": 4294705152
}
Hash = 95b70c8d

Additional context

No response

[SamVerschueren]

Hi @zveroboy. Thanks for reaching out! This is indeed a limitation and very hard to fix due to browser limitations. We already track this internally so we can improve the event loop over time.

You can find more information on this topic in this thread #980.