generator-ticker

What is this?

Do things, particularly async things, on a regular interval. Avoid drift, by treating the interval as a maximum rate, adjusting for slow receivers, and dropping missed ticks if necessary.

This implementation was inspired by Go's time.NewTicker.

Usage

const {newTicker} = require('generator-ticker');

// the last three parameters (count, initial, start) are optional
for await (const tick of newTicker(500, 3, false, new Date(0))) {
  console.log(`${tick.getSeconds()}s${tick.getMilliseconds()}ms\n`);
}

// will output something similar to:
// 52s500ms
// 53s0ms
// 53s500ms

Installation

Install or import the NPM package generator-ticker. Should work in most environments, including browsers, Node.js, and Deno.

API

Table of Contents

• newTicker
  • Parameters

newTicker

Creates an asynchronous ticker that yields Date objects at a specified interval. The ticker will adjust the interval or drop ticks, to make up for slow receivers. It avoids drift by using the time from the last tick as the basis for the next tick.

Parameters

• interval number {number} The interval duration, in milliseconds. Must be a number >= 0.
• count {number} The number of times to tick. A negative value indicates an unlimited number of times. Defaults to -1 (unlimited). (optional, default -1)
• initial {boolean} If true, the ticker will immediately yield the current Date as the first tick. Defaults to false. (optional, default false)
• start any? {Date} The start time for the ticker. Defaults to the current time. This is useful if you want to lock your ticker to certain wall times (requires picking an interval that divides evenly into 24 hours). This parameter interacts with the initial parameter. If initial is true, the first tick will be at the start time. Otherwise, the first tick will be at the start time + interval.

Returns AsyncGenerator<Date, void> An AsyncGenerator that yields Dates at the given interval.