mantoni

simenb

cjohansen

fatso83

mrgnrdrck

benjamin.gruenbaum

@sinonjs/fake-timers

  "description": "Fake JavaScript timers",

  "homepage": "https://github.com/sinonjs/fake-timers",

    "url": "https://github.com/sinonjs/fake-timers.git"

    "url": "https://github.com/sinonjs/fake-timers/issues"

    "test-node": "mocha --timeout 200 test/ integration-test/ -R dot --check-leaks",

    "test-headless": "mochify --no-detect-globals --timeout=10000",

    "test-check-coverage": "npm run test-coverage && nyc check-coverage",

    "test-cloud": "mochify --wd --no-detect-globals --timeout=10000",

    "test-coverage": "nyc --all --reporter text --reporter html --reporter lcovonly npm run test-node",

    "test": "npm run test-node && npm run test-headless",

    "prettier:check": "prettier --check '**/*.{js,css,md}'",

    "prettier:write": "prettier --write '**/*.{js,css,md}'",

    "preversion": "./scripts/preversion.sh",

    "postversion": "./scripts/postversion.sh",

[![codecov](https://codecov.io/gh/sinonjs/fake-timers/branch/main/graph/badge.svg)](https://codecov.io/gh/sinonjs/fake-timers)

JavaScript implementation of the timer APIs; `setTimeout`, `clearTimeout`, `setImmediate`, `clearImmediate`, `setInterval`, `clearInterval`, `requestAnimationFrame`, `cancelAnimationFrame`, `requestIdleCallback`, and `cancelIdleCallback`, along with a clock instance that controls the flow of time. FakeTimers also provides a `Date` implementation that gets its time from the clock.

In addition in browser environment `@sinonjs/fake-timers` provides a `performance` implementation that gets its time from the clock. In Node environments FakeTimers provides a `nextTick` implementation that is synchronized with the clock - and a `process.hrtime` shim that works with the clock.

`@sinonjs/fake-timers` can be used to simulate passing time in automated tests and other

situations where you want the scheduling semantics, but don't want to actually

`@sinonjs/fake-timers` is extracted from [Sinon.JS](https://github.com/sinonjs/sinon.js) and targets the [same runtimes](https://sinonjs.org/releases/latest/#supported-runtimes).

## Autocomplete, IntelliSense and TypeScript definitions

Version 7 introduced JSDoc to the codebase. This should provide autocomplete and type suggestions in supporting IDEs. If you need more elaborate type support, TypeScript definitions for the Sinon projects are independently maintained by the Definitely Types community:

npm install -D @types/sinonjs__fake-timers

`@sinonjs/fake-timers` can be used in both Node and browser environments. Installation is as easy as

If you want to use `@sinonjs/fake-timers` in a browser you can either build your own bundle or use [Skypack](https://www.skypack.dev).

To use `@sinonjs/fake-timers`, create a new clock, schedule events on it using the timer

functions and pass time using the `tick` method.

// In the browser distribution, a global `FakeTimers` is already available

var FakeTimers = require("@sinonjs/fake-timers");

        "The poblano is a mild chili pepper originating in the state of Puebla, Mexico."

Upon executing the last line, an interesting fact about the

[Poblano](https://en.wikipedia.org/wiki/Poblano) will be printed synchronously to

the screen. If you want to simulate asynchronous behavior, please see the `async` function variants (eg `clock.tick(time)` vs `await clock.tickAsync(time)`).

The `next`, `runAll`, `runToFrame`, and `runToLast` methods are available to advance the clock. See the

When using `@sinonjs/fake-timers` to test timers, you will most likely want to replace the native

timers such that calling `setTimeout` actually schedules a callback with your

clock instance, not the browser's internals.

Calling `install` with no arguments achieves this. You can call `uninstall`

later to restore things as they were again.

// var clock = FakeTimers.install(typeof global !== "undefined" ? global : window);

setTimeout(fn, 15); // Schedules with clock.setTimeout

// setTimeout is restored to the native implementation

To hijack timers in another context pass it to the `install` method.

    setTimeout: setTimeout, // By default context.setTimeout uses the global setTimeout

var clock = FakeTimers.withGlobal(context).install();

context.setTimeout(fn, 15); // Schedules with clock.setTimeout

// context.setTimeout is restored to the original implementation

Usually you want to install the timers onto the global object, so call `install`

Advance the clock by jumping forward in time, firing callbacks at most once.

`time` takes the same formats as [`clock.tick`](#clockticktime--await-clocktickasynctime).

This can be used to simulate the JS engine (such as a browser) being put to sleep and resumed later, skipping intermediary timers.

Removes all timers and ticks without firing them, and sets `now` to `config.now`

that was provided to `FakeTimers.install` or to `0` if `config.now` was not provided.

Useful to reset the state of the clock without having to `uninstall` and `install` it.

### `clock.runAll()` / `await clock.runAllAsync()`

This runs all pending timers until there are none remaining. If new timers are added while it is executing they will be run as well.

This makes it easier to run asynchronous tests to completion without worrying about the number of timers they use, or the delays in those timers.

It runs a maximum of `loopLimit` times after which it assumes there is an infinite loop of timers and throws an error.

The `runAllAsync()` will also break the event loop, allowing any scheduled promise

callbacks to execute _before_ running the timers.

This runs all pending microtasks scheduled with `nextTick` but none of the timers and is mostly useful for libraries using FakeTimers underneath and for running `nextTick` items without any timers.

Advances the clock to the next frame, firing all scheduled animation frame callbacks,

if any, for that frame as well as any other timers scheduled along the way.

### `clock.runToLast()` / `await clock.runToLastAsync()`

This takes note of the last scheduled timer when it is run, and advances the

clock to that time firing callbacks as necessary.

If new timers are added while it is executing they will be run only if they

This is useful when you want to run a test to completion, but the test recursively

sets timers that would cause `runAll` to trigger an infinite loop warning.

The `runToLastAsync()` will also break the event loop, allowing any scheduled promise

This simulates a user changing the system clock while your program is running.

It affects the current time but it does not in itself cause e.g. timers to fire;

they will fire exactly as they would have done without the call to

Restores the original methods of the native timers or the methods on the object

that was passed to `FakeTimers.withGlobal`

Implements the `Date` object but using the clock to provide the correct time.

Implements the `now` method of the [`Performance`](https://developer.mozilla.org/en-US/docs/Web/API/Performance/now) object but using the clock to provide the correct time. Only available in environments that support the Performance object (browsers mostly).

In order to support creating clocks based on separate or sandboxed environments (such as JSDOM), FakeTimers exports a factory method which takes single argument `global`, which it inspects to figure out what to mock and what features to support. When invoking this function with a global, you will get back an object with `timers`, `createClock` and `install` - same as the regular FakeTimers exports only based on the passed in global instead of the global environment.

FakeTimers has a comprehensive test suite. If you're thinking of contributing bug

fixes or suggesting new features, you need to make sure you have not broken any

tests. You are also expected to add tests for any new behavior.

$(npm bin)/mocha ./test/fake-timers-test.js

[Mochify](https://github.com/mantoni/mochify.js) is used to run the tests in

PhantomJS. Make sure you have `phantomjs` installed. Then:

BSD 3-clause "New" or "Revised" License (see LICENSE file)

const globalObject = require("@sinonjs/commons").global;

 * @property {boolean} didTimeout - whether or not the callback was called before reaching the optional timeout

 * @property {function():number} timeRemaining - a floating-point value providing an estimate of the number of milliseconds remaining in the current idle period

 * Queues a function to be called during a browser's idle periods

 * @param {function(IdleDeadline)} callback

 * @param {{timeout: number}} options - an options object

 * @param {VoidVarArgsFunc} callback - the callback to run

 * @param {...*} arguments - optional arguments to call the callback with

 * @param {...*} callback - the callback to run

 * @property {function(number):void} requestAnimationFrame

/* eslint-disable jsdoc/require-property-description */

 * @property {number} now - the current time

 * @property {Date} Date - the Date constructor

 * @property {number} loopLimit - the maximum number of timers before assuming an infinite loop

 * @property {RequestIdleCallback} requestIdleCallback

 * @property {function(number):void} cancelIdleCallback

 * @property {queueMicrotask} queueMicrotask

 * @property {clearInterval} clearInterval

 * @property {function(NodeImmediate):void} clearImmediate

 * @property {function():number} countTimers

 * @property {RequestAnimationFrame} requestAnimationFrame

 * @property {function(number):void} cancelAnimationFrame

 * @property {function():void} runMicrotasks

 * @property {function(string | number): number} tick

 * @property {function(string | number): Promise<number>} tickAsync

 * @property {function(): Promise<number>} nextAsync

 * @property {function(): number} runToFrame

 * @property {function(): Promise<number>} runAllAsync

 * @property {function(): number} runToLast

 * @property {function(): Promise<number>} runToLastAsync

 * @property {function(number | Date): void} setSystemTime

 * @property {function(number): void} jump

 * @property {function(number[]): number[]} hrtime - process.hrtime (legacy)

 * @property {function(): void} uninstall Uninstall the clock.

 * @property {Function[]} methods - the methods that are faked

 * @property {boolean} [shouldClearNativeTimers] inherited from config

/* eslint-enable jsdoc/require-property-description */

 * Configuration object for the `install` method.

 * @property {number|Date} [now] a number (in milliseconds) or a Date object (default epoch)

 * @property {string[]} [toFake] names of the methods that should be faked.

 * @property {number} [loopLimit] the maximum number of timers that will be run when calling runAll()

 * @property {boolean} [shouldAdvanceTime] tells FakeTimers to increment mocked time automatically (default false)

 * @property {number} [advanceTimeDelta] increment mocked time every <<advanceTimeDelta>> ms (default: 20ms)

 * @property {boolean} [shouldClearNativeTimers] forwards clear timer calls to native functions if they are not fakes (default: false)

 * The internal structure to describe a scheduled fake timer

 * @property {function(): boolean} hasRef

 * @property {function(): NodeImmediate} ref

 * @property {function(): NodeImmediate} unref

 * Mocks available features in the specified global namespace.

 * @param {*} _global Namespace to mock (e.g. `window`)

    const userAgent = _global.navigator && _global.navigator.userAgent;

    const isRunningInIE = userAgent && userAgent.indexOf("MSIE ") > -1;

    const maxTimeout = Math.pow(2, 31) - 1; //see https://heycam.github.io/webidl/#abstract-opdef-converttoint

    const idCounterStart = 1e12; // arbitrarily large number to avoid collisions with native timer IDs

    const timeoutResult = _global.setTimeout(NOOP, 0);

    const addTimerReturnsObject = typeof timeoutResult === "object";

        _global.process && typeof _global.process.hrtime === "function";

        hrtimePresent && typeof _global.process.hrtime.bigint === "function";

        _global.process && typeof _global.process.nextTick === "function";

    const utilPromisify = _global.process && require("util").promisify;

        _global.performance && typeof _global.performance.now === "function";

        (typeof _global.Performance).match(/^(function|object)$/);

    const hasPerformanceConstructorPrototype =

        _global.performance.constructor &&

        _global.performance.constructor.prototype;

    const queueMicrotaskPresent = _global.hasOwnProperty("queueMicrotask");

        typeof _global.requestAnimationFrame === "function";

        typeof _global.cancelAnimationFrame === "function";

        typeof _global.requestIdleCallback === "function";

        typeof _global.cancelIdleCallback === "function";

        _global.setImmediate && typeof _global.setImmediate === "function";

    // Make properties writable in IE, as per

    // https://www.adequatelygood.com/Replacing-setTimeout-Globally.html

         * @param {string|number} tickValue number of milliseconds or a human-readable value like "01:11:15"

         * @returns {number} will return the new `now` value

        clock.jump = function jump(tickValue) {

                typeof tickValue === "number"

                    : parseTime(tickValue);

            const ms = Math.floor(msFloat);

            for (const timer of Object.values(clock.timers)) {

                if (clock.now + ms > timer.callAt) {

                    timer.callAt = clock.now + ms;

            clock.performance = Object.create(null);

            clock.performance.now = fakePerformanceNow;

     * @param {Config=} [config] Optional config

                `FakeTimers.install called with ${String(

                )} install requires an object parameter`

        if (_global.Date.isFake === true) {

            // Timers are already faked; this is a problem.

            // Make the user reset timers before continuing.

                "Can't install fake timers twice on the same global object."

        // eslint-disable-next-line no-param-reassign

        config = typeof config !== "undefined" ? config : {};

        config.shouldAdvanceTime = config.shouldAdvanceTime || false;

        config.advanceTimeDelta = config.advanceTimeDelta || 20;

            config.shouldClearNativeTimers || false;

                "config.target is no longer supported. Use `withGlobal(target)` instead."

        const clock = createClock(config.now, config.loopLimit);

        clock.shouldClearNativeTimers = config.shouldClearNativeTimers;

            return uninstall(clock, config);

        clock.methods = config.toFake || [];

        if (clock.methods.length === 0) {

            // do not fake nextTick by default - GitHub#126

            clock.methods = Object.keys(timers).filter(function (key) {

                return key !== "nextTick" && key !== "queueMicrotask";

        if (config.shouldAdvanceTime === true) {

            const intervalTick = doIntervalTick.bind(

            const intervalId = _global.setInterval(

		{
		"name": "@sinonjs/fake-timers",
		"description": "Fake JavaScript timers",
		"version": "10.0.2",
		"version": "10.1.0",
		"homepage": "https://github.com/sinonjs/fake-timers",
		@@ -39,15 +39,15 @@ "author": "Christian Johansen",
		"devDependencies": {
		"@sinonjs/eslint-config": "4.0.6",
		"@sinonjs/referee-sinon": "10.1.0",
		"husky": "^8.0.0",
		"jsdom": "20.0.2",
		"lint-staged": "13.0.3",
		"mocha": "10.1.0",
		"@sinonjs/eslint-config": "^4.1.0",
		"@sinonjs/referee-sinon": "11.0.0",
		"husky": "^8.0.3",
		"jsdom": "22.0.0",
		"lint-staged": "13.2.2",
		"mocha": "10.2.0",
		"mochify": "9.2.0",
		"nyc": "15.1.0",
		"prettier": "2.7.1"
		"prettier": "2.8.8"
		},
		"main": "./src/fake-timers-src.js",
		"dependencies": {
		"@sinonjs/commons": "^2.0.0"
		"@sinonjs/commons": "^3.0.0"
		},
		@@ -54,0 +54,0 @@ "nyc": {

		@@ -258,2 +258,9 @@ # `@sinonjs/fake-timers`

		### `clock.jump(time)`

		Advance the clock by jumping forward in time, firing callbacks at most once.
		`time` takes the same formats as [`clock.tick`](#clockticktime--await-clocktickasynctime).

		This can be used to simulate the JS engine (such as a browser) being put to sleep and resumed later, skipping intermediary timers.

		### `clock.reset()`
		@@ -260,0 +267,0 @@

Improved metrics

Dependency changes

		@@ -82,2 +82,3 @@ "use strict";
		* @property {function(number \| Date): void} setSystemTime
		* @property {function(number): void} jump
		* @property {Performance} performance
		@@ -1609,2 +1610,21 @@ * @property {function(number[]): number[]} hrtime - process.hrtime (legacy)

		/**
		* @param {string\|number} tickValue number of milliseconds or a human-readable value like "01:11:15"
		* @returns {number} will return the new `now` value
		*/
		clock.jump = function jump(tickValue) {
		const msFloat =
		typeof tickValue === "number"
		? tickValue
		: parseTime(tickValue);
		const ms = Math.floor(msFloat);

		for (const timer of Object.values(clock.timers)) {
		if (clock.now + ms > timer.callAt) {
		timer.callAt = clock.now + ms;
		}
		}
		clock.tick(ms);
		};

		if (performancePresent) {
		@@ -1611,0 +1631,0 @@ clock.performance = Object.create(null);