jest-time-helpers/dist/index.d.ts

Helpers you can use in tests that relate to the passage of time (i.e. code that involves setTimeout, setInterval, new Date(), Date.now(), etc)

/// <reference types="node" />
/**
 * Wait a number of milliseconds of _real time_ (not mocked time); useful for
 * allowing the runloop or external systems to advance.
 *
 * @param ts - how long to sleep for.
 */
export declare const sleep: (ms: number, unref?: boolean) => Promise<void> & {
    timeout: NodeJS.Timeout;
};
/**
 * Polls until the condition passes.
 *
 * Polls the `condition` callback every `pollInterval` ms of real time. If/when
 * it returns a truthy value, resolves successfully. If `maxDuration` is
 * exceeded before `condition()` returns true, rejects with an error.
 *
 * @param condition - a callback function that should return true when no more sleep is required
 * @param maxDuration - an optional maximum duration to sleep
 * @param pollInterval - an optional period of how long we should wait between checks; lower values increase load on the server but may make tests pass faster, larger values are more efficient but increase test latency.
 */
export declare function sleepUntil(condition: () => boolean, maxDuration?: number, pollInterval?: number): Promise<void>;
/**
 * Sets up fake timers and Date implementation within your Jest test file. You
 * should call this at the top of the file (**not** within a test or an
 * after/before); tests that need fake timers should go into their own test
 * file.
 *
 * Returns an object containing a `setTime` function which you can use to set
 * the current (fake) date within your test to a particular JavaScript
 * timestamp (number of milliseconds since 1970-01-01T00:00:00Z).
 *
 * Enables the `jest.useFakeTimers()` integration, and overwrites `global.Date`
 * with a custom function that automatically applies your test file's given
 * offset.
 */
export declare function setupFakeTimers(): {
    setTime: (timestamp: number, increment?: number) => Promise<void>;
    realNow: () => number;
};
/** One second in milliseconds */
export declare const SECOND = 1000;
/** One minute in milliseconds */
export declare const MINUTE: number;
/** One hour in milliseconds */
export declare const HOUR: number;
/** One day in milliseconds */
export declare const DAY: number;
/** One week in milliseconds */
export declare const WEEK: number;