timeout-flow

Fluent, human-readable time control for JavaScript. A modern, composable upgrade to setTimeout and setInterval with chaining, conditional logic, pause/resume control, retries, and RAF utilities.

Features

• Readable durations: "1s", "500ms", plain numbers
• Pause / resume / cancel controllers for after(), every(), RAF variants
• flow() builds declarative timelines with branching and labels
• retry() with backoff, jitter, and AbortSignal cancellation
• waitFor() polls a predicate with timeout
• RAF variants (afterRaf, everyRaf, debounceRaf, throttleRaf, waitForRaf) for frame-aligned timing
• ESM-first, tree-shakeable. Per-file subpath exports for size-sensitive consumers (~1.2 KB gzipped for a single primitive)
• Zero dependencies
• ~6–7 KB minified for the full kit (~2–3 KB gzipped)

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Install

pnpm add timeout-flow

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Quick start

import { after } from 'timeout-flow';

function greet() {
  console.log('Hello');
}

const ctrl = after('2s', greet);

ctrl.pause();
ctrl.resume();
ctrl.cancel();

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API

after(duration, fn, options?)

Run once after a delay.

import { after } from 'timeout-flow';

after('2s', function greet() {
  console.log('Hello');
});

every(duration, fn, options?)

Repeat execution with optional limit.

import { every } from 'timeout-flow';

const ticker = every('1s', function tick(i) {
  console.log('Tick', i);
}, { max: 5 });

debounce(duration, fn, options?)

Delay execution until inactivity.

import { debounce } from 'timeout-flow';

const debouncedSearch = debounce('300ms', function search(event) {
  console.log('Searching for:', event.target.value);
});

debouncedSearch.cancel();
debouncedSearch.flush();

throttle(duration, fn, options?)

Limit execution frequency.

import { throttle } from 'timeout-flow';

const onScroll = throttle('250ms', function handleScroll() {
  console.log('scroll');
});

onScroll.cancel();
onScroll.flush();

retry(fn, options?)

Retry async operations with backoff and jitter.

import { retry } from 'timeout-flow';

await retry(async function fetchData() {
  return fetch('/api/data');
}, {
  attempts: 5,
  delay: '500ms',
  backoff: true,
  factor: 2,
  maxDelay: '5s',
  jitter: 'decorrelated'
});

waitFor(predicate, options?)

Wait until a condition becomes true.

import { waitFor } from 'timeout-flow';

await waitFor(function checkLoaded() {
  return document.querySelector('#loaded');
}, {
  interval: '250ms',
  timeout: '5s',
  immediate: true
});

flow()

Build declarative time flows.

import { flow } from 'timeout-flow';

flow()
  .after('1s', function stepOne() {
    console.log('Step 1');
  })
  .every('500ms', function tick(i) {
    console.log('Tick', i);
  }, { max: 3 })
  .after('1s', function finalStep() {
    console.log('Final Step');
  })
  .start();

Flow reads like a timeline and keeps duration-first ordering for readability.

RAF utilities

Frame-based timing powered by requestAnimationFrame. Ideal for visual updates, scroll handlers, layout checks, and animation loops.

Available: afterRaf(), everyRaf(), debounceRaf(), throttleRaf(), waitForRaf().

import { throttleRaf } from 'timeout-flow';

const onScroll = throttleRaf(function drawFrame() {
  console.log('draw');
});

onScroll.cancel();
onScroll.flush();

Controllers

Most time-based primitives return a controller object:

const ctrl = after('1s', () => console.log('done'));

ctrl.pause();
ctrl.resume();
ctrl.cancel();
ctrl.reset?.();

console.log(ctrl.isRunning);
console.log(ctrl.isPaused);
console.log(ctrl.isFinished);

Shared by after(), every(), afterRaf(), everyRaf(). All controllers are pause-safe (paused time does not count), cancel-safe, monotonic-time based, and AbortSignal-aware where supported.

AbortSignal support

Many utilities accept { signal } for automatic cancellation.

import { after } from 'timeout-flow';

const ac = new AbortController();

after('2s', function doWork() {
  console.log('Will not run if aborted');
}, { signal: ac.signal });

ac.abort();

If already aborted at creation time, no work is scheduled.

Public surface

import {
  after,
  every,
  debounce,
  throttle,
  retry,
  waitFor,
  flow,

  afterRaf,
  everyRaf,
  debounceRaf,
  throttleRaf,
  waitForRaf
} from 'timeout-flow';

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Notes

Tree-shaking and per-primitive imports

Two import styles, same package, choose by bundle-size sensitivity:

// Full kit. Every primitive available on one import.
// Modern bundlers (esbuild, vite, rollup, webpack 5) will tree-shake
// unused exports because the package ships `sideEffects: false` and the
// `.` entrypoint points at ESM source instead of a pre-minified blob.
import { after, debounce, retry } from 'timeout-flow';

// Per-primitive subpath. Explicit minimum surface, useful when you know
// you only need one primitive and want the bundle to reflect that
// without relying on the bundler's tree-shaker. Same source either way.
import { after }     from 'timeout-flow/after';
import { every }     from 'timeout-flow/every';
import { debounce }  from 'timeout-flow/debounce';
import { throttle }  from 'timeout-flow/throttle';
import { retry }     from 'timeout-flow/retry';
import { waitFor }   from 'timeout-flow/wait-for';
import { flow }      from 'timeout-flow/flow';
import { afterRaf, everyRaf, debounceRaf, throttleRaf, waitForRaf } from 'timeout-flow/raf';
import { parseDuration } from 'timeout-flow/parse-duration';

Measured for a single after() call in a typical browser bundler (esbuild, minified + gzip):

Import style	Gzip
pre-0.0.19 default (full minified bundle)	5098 bytes
0.0.19 default (import { after } from 'timeout-flow')	1199 bytes
0.0.19 subpath (import { after } from 'timeout-flow/after')	1199 bytes

For unbundled <script type="module"> consumption of the full kit, use the timeout-flow/min subpath, which points at the pre-built minified IIFE.

Clean signatures

timeout-flow supports both natural-language and function-first argument ordering:

after('1s', done);
// or
after(done, '1s');

This applies to after(), every(), debounce(), throttle(). Use whichever reads best in your codebase.

Philosophy

timeout-flow is not just a wrapper around timers, it's a composable toolkit for expressing time as readable logic. Temporal behavior should be:

• Readable. Durations like "1s" and "500ms" beat magic numbers.
• Composable. Sequencing should be declarative.
• Controllable. Timers should pause, resume, cancel.
• Branchable. Real flows need if, while, label, jumpTo().
• Tiny. No runtime bloat.

Think of timeout-flow as setTimeout() with superpowers.

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License

Licensed under AGPL-3.0 with WATT3D Additional Terms. See LICENSE and ADDITIONAL_TERMS.md. Commercial AI/model-training use requires compliance with those terms or a separate WATT3D license. © WATT3D.