flush-microtasks

library1.0.1jsnpmunverified

Utility to flush the microtask queue (e.g., pending Promises) by returning a thenable that resolves when the queue is empty. Version 1.0.1 is stable, with no recent releases. It is a minimal, focused library extracted from React's enqueueTask implementation, ideal for testing or scenarios requiring deterministic microtask execution. Differentiates by providing a simple, dependency-free function without side effects.

testing

npm install flush-microtasks

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · FLUSH-MICROTASKS

flush-microtasks

testingjavascriptv1.0.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

flushMicroTasks

✓ import { flushMicroTasks } from 'flush-microtasks'

✗ const flushMicroTasks = require('flush-microtasks')

Package is ESM-only and does not support CommonJS require. Use named import.

flushMicroTasks (default import attempt)

✓ import { flushMicroTasks } from 'flush-microtasks'

✗ import flushMicroTasks from 'flush-microtasks'

The package has only a named export, no default export.

TypeScript type

✓ import type { flushMicroTasks } from 'flush-microtasks'

✗ import { flushMicroTasks } from 'flush-microtasks' // for types only

The package does not export types separately; use `typeof` if needed.

Demonstrates using flushMicroTasks to wait for pending microtasks (Promise callbacks) to complete before proceeding.

import { flushMicroTasks } from 'flush-microtasks'; async function example() { console.log('Before flush'); Promise.resolve().then(() => console.log('Microtask')); await flushMicroTasks(); console.log('After flush'); } example(); // Output: "Before flush" -> "Microtask" -> "After flush"

Debug

Known issues

gotchaflushMicroTasks() only resolves after the current microtask queue is empty. If new microtasks are added during flush, they will not be waited for.

fix

Call flushMicroTasks() again or use a loop if you need to drain continuously added microtasks.

affects: >=1.0.0

breakingThe export is named, not default. Attempting a default import will result in undefined.

fix

Use named import: import { flushMicroTasks } from 'flush-microtasks'

affects: >=1.0.0

gotchaThe function is not exported as a CommonJS module; require() will not work.

fix

Use ES module import syntax.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: flushMicroTasks is not a function

Default import used instead of named import.

fix

Change to: import { flushMicroTasks } from 'flush-microtasks'

Error: Cannot find module 'flush-microtasks'

Trying to use require() in an ESM-only package.

fix

Use import syntax or add "type": "module" to package.json.

Upgrade

Version history

1.0.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/aleclarson/flush-microtasks ↗

packageflush-microtasks ↗

homepagehttps://github.com/aleclarson/flush-microtasks#readme ↗