callBeforeAppShutdownHook

Kind: Function

Source: packages/core/hooks/before-app-shutdown.hook.ts

Part of: Core

Calls the beforeApplicationShutdown function on the module and its children (providers / controllers).

callBeforeAppShutdownHook invokes the beforeApplicationShutdown lifecycle hook for a module’s providers, controllers, and module class. It coordinates shutdown hook execution for static dependency trees and forwards the optional operating-system shutdown signal to each eligible instance.

Signature

ts
async function callBeforeAppShutdownHook(module: Module, signal: string): Promise<void>

Parameters

Returns: Promise<void>

Diagram

mermaid
graph LR
  A[Application shutdown signal] --> B[callBeforeAppShutdownHook]
  B --> C[Module providers]
  B --> D[Module controllers]
  B --> E[Module class instance]
  C --> F[beforeApplicationShutdown(signal)]
  D --> F
  E --> F

Usage

ts
import { callBeforeAppShutdownHook } from '@nestjs/core/hooks/before-app-shutdown.hook';
import { ModulesContainer } from '@nestjs/core';

async function runShutdownHooks(
  modulesContainer: ModulesContainer,
  signal = 'SIGTERM',
) {
  for (const moduleRef of modulesContainer.values()) {
    await callBeforeAppShutdownHook(moduleRef, signal);
  }
}

AI Coding Instructions

• Preserve the lifecycle execution order: providers and controllers should run before the module class hook.
• Always forward the optional shutdown signal, such as SIGTERM or SIGINT, to beforeApplicationShutdown.
• Await hook execution so asynchronous cleanup tasks, such as closing database connections, finish before shutdown continues.
• Only invoke hooks for eligible static dependency trees; transient or request-scoped instances require the existing instance-selection logic.
• Treat this as framework lifecycle infrastructure—prefer enabling application shutdown hooks rather than calling it directly in application code.

Relationships

• IMPORTS → BeforeApplicationShutdown
• IMPORTS → isFunction
• IMPORTS → isNil