nexttick.js

const fs = require("fs");
setImmediate(() => {
  process.stdout.write(`setImmediate (after poll phase)\n`);
  process.nextTick(() => {
    process.stdout.write(`nextTick (nested registered in setImmediate())\n`);
  });
});

setTimeout(() => {
  process.stdout.write(`setTimeout (timers phase)\n`);
  process.nextTick(() => {
    process.stdout.write(`nextTick (nested registered in setTimeout())\n`);
  });
}, 0);

fs.readdir("./", (err, data) => {
  process.stdout.write(`readdir (poll phase)\n`);
  process.nextTick(() => {
    process.stdout.write(`nextTick (nested registered in readdir())\n`);
  });
});

process.nextTick(() => {
  process.stdout.write(`nextTick (registered on top level)\n`);
});

// Output:
/*
nextTick (registered on top level)
setTimeout (timers phase)
nextTick (nested registered in setTimeout())
readdir (poll phase)
nextTick (nested registered in readdir())
setImmediate (after poll phase)
nextTick (nested registered in setImmediate())
*/

This example looks good. Thanks @danielkhan

Also, i added setImmediate inside setTimeout to verify once more if process.nextTick(function(){}) (without i/o) gets executed after every phase in the eventLoop. From the output i received i can infer the answer as yes.

const fs = require("fs");
setImmediate(() => {
  process.stdout.write(`setImmediate (after poll phase)\n`);
  process.nextTick(() => {
    process.stdout.write(`nextTick (nested registered in setImmediate())\n`);
  });
});

setTimeout(() => {
  process.stdout.write(`setTimeout (timers phase)\n`);
  /* new start */
  setImmediate(()=>{
    process.stdout.write(`setTimeout (setImmediate phase)\n`);
  })
  /* new end */
  process.nextTick(() => {
    process.stdout.write(`nextTick (nested registered in setTimeout())\n`);
  });
}, 0);

fs.readdir("./", (err, data) => {
  process.stdout.write(`readdir (poll phase)\n`);
  process.nextTick(() => {
    process.stdout.write(`nextTick (nested registered in readdir())\n`);
  });
});

process.nextTick(() => {
  process.stdout.write(`nextTick (registered on top level)\n`);
});

// Output:
/*
nextTick (registered on top level)
setTimeout (timers phase)
nextTick (nested registered in setTimeout())
readdir (poll phase)
nextTick (nested registered in readdir())
setImmediate (after poll phase)
nextTick (nested registered in setImmediate())
setTimeout (setImmediate phase)
*/