Understanding process.nextTick

In Bnlang, process.nextTick is a special function that schedules a callback to run immediately after the current operation, before the event loop continues.
It gives a way to defer execution without waiting for the next event loop phase.
Think of it as microtask scheduling, ensuring the function runs as soon as possible after the current stack clears.

Basic Example

console.log("Start");

process.nextTick(() => {
  console.log("NextTick callback");
});

console.log("End");

// Output:
// Start
// End
// NextTick callback

Comparison with setImmediate and setTimeout

  • process.nextTick → Runs before the event loop continues (highest priority microtask).
  • setImmediate → Runs in the check phase of the event loop (after I/O).
  • setTimeout → Runs after a minimum delay in the timers phase.

Example: nextTick vs setImmediate

process.nextTick(() => console.log("nextTick"));
setImmediate(() => console.log("setImmediate"));

console.log("Done");

// Output:
// Done
// nextTick
// setImmediate

Best Practices

  • Use process.nextTick for very short deferrals that must run before I/O.
  • Avoid heavy logic inside nextTick to prevent blocking other microtasks.
  • Prefer promises (Promise.resolve().then(...)) for clearer async code when possible.