ExceptionsZone

Kind: Class

Source: packages/core/errors/exceptions-zone.ts

Part of: Core

ExceptionsZone executes synchronous or asynchronous bootstrap work within a centralized exception boundary. It delegates caught errors to Nest's exception handling and logging infrastructure, then runs a teardown callback—by default terminating the process.

Methods

When something fails

• ExceptionsZone handles failure in 2 places: it logs it and continues in all 2.

Diagram

mermaid
graph LR
  A[Application bootstrap callback] --> B{ExceptionsZone.run / asyncRun}
  B -->|Success| C[Continue execution]
  B -->|Throws or rejects| D[ExceptionHandler]
  D --> E[Flush logs]
  E --> F[Teardown callback]
  F --> G[Exit process by default]

Usage

ts
import { ExceptionsZone } from '@nestjs/core/errors/exceptions-zone';

async function bootstrap() {
  // Create and start the application here.
  console.log('Application started');
}

ExceptionsZone.asyncRun(
  bootstrap,
  error => {
    console.error('Bootstrap failed:', error);
    process.exitCode = 1;
  },
);

AI Coding Instructions

• Use run() for synchronous callbacks and asyncRun() for callbacks that return a Promise.
• Provide a custom teardown callback when callers need cleanup, test-friendly behavior, or custom process-exit handling.
• Do not catch and silently ignore errors inside the callback; allow unrecoverable bootstrap errors to reach ExceptionsZone.
• Preserve the exception handler and log-flushing flow when modifying this class, as it ensures startup failures are reported consistently.
• Treat this as core bootstrap infrastructure; application-level request exceptions should use Nest exception filters instead.

Relationships

• IMPORTS → Logger