feat: allow async serviceErrorHandler method (#1158)

closes #1157

Author: jmcdo29

.changeset/late-snakes-join.md

@@ -0,0 +1,5 @@
+---
+'nest-commander': minor
+---
+
+feat: allow async `serviceErrorHandler` method

packages/nest-commander/src/command-factory.interface.ts

@@ -4,6 +4,7 @@ import { Help, OutputConfiguration } from 'commander';
 import type { CompletionFactoryOptions } from './completion.factory.interface';
 
 export type ErrorHandler = (err: Error) => void;
+export type ServiceErrorHandler = (err: Error) => PromiseLike<void> | void;
 export type NestLogger = LoggerService | LogLevel[] | false;
 
 export interface DefinedCommandFactoryRunOptions
@@ -18,7 +19,7 @@ export interface CommandFactoryRunOptions
   errorHandler?: ErrorHandler;
   usePlugins?: boolean;
   cliName?: string;
-  serviceErrorHandler?: ErrorHandler;
+  serviceErrorHandler?: ServiceErrorHandler;
   enablePositionalOptions?: boolean;
   enablePassThroughOptions?: boolean;
   outputConfiguration?: OutputConfiguration;

packages/nest-commander/src/command-runner.service.ts

@@ -61,8 +61,9 @@ ${cliPluginError(
       this.commander.exitOverride(this.options.errorHandler);
     }
     if (!this.options.serviceErrorHandler) {
-      this.options.serviceErrorHandler = (err: Error) =>
+      this.options.serviceErrorHandler = (err: Error) => {
         process.stderr.write(err.toString());
+      };
     }
     if (this.options.outputConfiguration) {
       this.commander.configureOutput(this.options.outputConfiguration);