fix: add process exit handler

Author: John Doe

packages/utils/src/lib/exit-process.ts

@@ -0,0 +1,43 @@
+import process from 'node:process';
+
+/* eslint-disable  @typescript-eslint/no-magic-numbers */
+const SIGNALS = [
+  ['SIGINT', 130],
+  ['SIGTERM', 143],
+  ['SIGQUIT', 131],
+] as const;
+/* eslint-enable  @typescript-eslint/no-magic-numbers */
+
+export type FatalKind = 'uncaughtException' | 'unhandledRejection';
+type ExitHandlerOptions =
+  | {
+      onClose?: () => void;
+      onFatal: (err: unknown, kind?: FatalKind) => void;
+    }
+  | {
+      onClose: () => void;
+      onFatal?: never;
+    };
+
+export function installExitHandlers(options: ExitHandlerOptions): void {
+  // Fatal errors
+  process.on('uncaughtException', err => {
+    options.onFatal?.(err, 'uncaughtException');
+  });
+
+  process.on('unhandledRejection', reason => {
+    options.onFatal?.(reason, 'unhandledRejection');
+  });
+
+  // Graceful shutdown signals
+  SIGNALS.forEach(([signal]) => {
+    process.on(signal, () => {
+      options.onClose?.();
+    });
+  });
+
+  // Normal exit
+  process.on('exit', () => {
+    options.onClose?.();
+  });
+}

packages/utils/src/lib/exit-process.unit.test.ts

@@ -0,0 +1,109 @@
+import process from 'node:process';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { installExitHandlers } from './exit-process.js';
+
+describe('exit-process tests', () => {
+  const onFatal = vi.fn();
+  const onClose = vi.fn();
+  const processOnSpy = vi.spyOn(process, 'on');
+  const processExitSpy = vi.spyOn(process, 'exit').mockImplementation(vi.fn());
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    [
+      'uncaughtException',
+      'unhandledRejection',
+      'SIGINT',
+      'SIGTERM',
+      'SIGQUIT',
+      'exit',
+    ].forEach(event => {
+      process.removeAllListeners(event);
+    });
+  });
+
+  it('should install event listeners for all expected events', () => {
+    expect(() => installExitHandlers({ onFatal, onClose })).not.toThrow();
+
+    expect(processOnSpy).toHaveBeenCalledWith(
+      'uncaughtException',
+      expect.any(Function),
+    );
+    expect(processOnSpy).toHaveBeenCalledWith(
+      'unhandledRejection',
+      expect.any(Function),
+    );
+    expect(processOnSpy).toHaveBeenCalledWith('SIGINT', expect.any(Function));
+    expect(processOnSpy).toHaveBeenCalledWith('SIGTERM', expect.any(Function));
+    expect(processOnSpy).toHaveBeenCalledWith('SIGQUIT', expect.any(Function));
+    expect(processOnSpy).toHaveBeenCalledWith('exit', expect.any(Function));
+  });
+
+  it('should call onFatal with error and kind for uncaughtException', () => {
+    expect(() => installExitHandlers({ onFatal })).not.toThrow();
+
+    const testError = new Error('Test uncaught exception');
+
+    (process as any).emit('uncaughtException', testError);
+
+    expect(onFatal).toHaveBeenCalledWith(testError, 'uncaughtException');
+    expect(onFatal).toHaveBeenCalledTimes(1);
+    expect(onClose).not.toHaveBeenCalled();
+  });
+
+  it('should call onFatal with reason and kind for unhandledRejection', () => {
+    expect(() => installExitHandlers({ onFatal })).not.toThrow();
+
+    const testReason = 'Test unhandled rejection';
+
+    (process as any).emit('unhandledRejection', testReason);
+
+    expect(onFatal).toHaveBeenCalledWith(testReason, 'unhandledRejection');
+    expect(onFatal).toHaveBeenCalledTimes(1);
+    expect(onClose).not.toHaveBeenCalled();
+  });
+
+  it('should call onClose and exit with code 0 for SIGINT', () => {
+    expect(() => installExitHandlers({ onClose })).not.toThrow();
+
+    (process as any).emit('SIGINT');
+
+    expect(onClose).toHaveBeenCalledTimes(1);
+    expect(onClose).toHaveBeenCalledWith();
+    expect(onFatal).not.toHaveBeenCalled();
+  });
+
+  it('should call onClose and exit with code 0 for SIGTERM', () => {
+    expect(() => installExitHandlers({ onClose })).not.toThrow();
+
+    (process as any).emit('SIGTERM');
+
+    expect(onClose).toHaveBeenCalledTimes(1);
+    expect(onClose).toHaveBeenCalledWith();
+    expect(onFatal).not.toHaveBeenCalled();
+  });
+
+  it('should call onClose and exit with code 0 for SIGQUIT', () => {
+    expect(() => installExitHandlers({ onClose })).not.toThrow();
+
+    (process as any).emit('SIGQUIT');
+
+    expect(onClose).toHaveBeenCalledTimes(1);
+    expect(onClose).toHaveBeenCalledWith();
+    expect(onFatal).not.toHaveBeenCalled();
+  });
+
+  it('should call onClose for normal exit', () => {
+    expect(() => installExitHandlers({ onClose })).not.toThrow();
+
+    (process as any).emit('exit');
+
+    expect(onClose).toHaveBeenCalledTimes(1);
+    expect(onClose).toHaveBeenCalledWith();
+    expect(onFatal).not.toHaveBeenCalled();
+    expect(processExitSpy).not.toHaveBeenCalled();
+  });
+});