closeout/exit-hook

import exitHook from 'closeout/exit-hook';
import { asyncExitHook, gracefulExit } from 'closeout/exit-hook';

FunctionsCopy Anchor Link

defaultCopy Anchor Link

The default export, declared as exitHook.

Register a synchronous hook. Returns the function that unregisters it.

Declared here and exported at the foot of the file: exit-hook's default is its exitHook, so an import exitHook from 'closeout/exit-hook' swap only works if ours is a default too, and this repository's lint wants every export last and grouped.

function exitHook(onExit: ExitHookCallback): () => void;

Returns () => void

asyncExitHookCopy Anchor Link

Register an asynchronous hook, bounded by wait.

wait is required and must be a positive number: asyncExitHook(fn, {}) and asyncExitHook(fn, { wait: 'abc' }) both throw, and both are graded.

function asyncExitHook(onExit: ExitHookCallback, options?: Partial<AsyncExitHookOptions>): () => void;

Returns () => void

gracefulExitCopy Anchor Link

Exit the way process.exit() cannot: asynchronous hooks get to run, and stdio is drained before the process goes.

The argument is the exit code, and it is named signal upstream. Kept as upstream names it, because a drop-in whose parameter names disagree with the incumbent's .d.ts is a drop-in that breaks the first person to use a named argument in their editor.

function gracefulExit(signal?: number): void;

Returns void

InterfacesCopy Anchor Link

AsyncExitHookOptionsCopy Anchor Link

interface AsyncExitHookOptions {
    /**
     * How long this hook may take, in milliseconds. Required and positive — `exit-hook` throws
     * on a missing or non-numeric value and its `type enforcing` case asserts both.
     */
    wait: number;
}

TypesCopy Anchor Link

ExitHookCallbackCopy Anchor Link

A hook takes the code the process is about to leave with.

type ExitHookCallback = (exitCode: number | string) => unknown;

OptionsCopy Anchor Link

type Options = AsyncExitHookOptions;