add empty command

src/decorators.ts

 import {
+  CommandConfigExtended,
   CommandDefinitionFun,
   CommandPutConfig,
   CommandPutConfigMap,
@@ -57,19 +58,19 @@ export const All = (path: string) => UseHttpRoute({ path, method: 'all' });
 
 export function UseCommand<D extends string>(
   def: D,
-  config?: Command.Config,
+  config?: CommandConfigExtended,
 ): MethodDecorator;
 export function UseCommand<D extends string>(
   def: D,
   desc: string,
-  config?: Command.Config,
+  config?: CommandConfigExtended,
 ): MethodDecorator;
 export function UseCommand(
   def: string,
-  ...args: [Command.Config?] | [string, Command.Config?]
+  ...args: [CommandConfigExtended?] | [string, CommandConfigExtended?]
 ): MethodDecorator {
   const desc = typeof args[0] === 'string' ? (args.shift() as string) : '';
-  const config = args[0] as Command.Config;
+  const config = args[0] as CommandConfigExtended;
   return (obj, key: string, des) => {
     const putOptions: CommandPutConfig<keyof CommandPutConfigMap>[] =
       Reflect.getMetadata(KoishiCommandPutDef, obj.constructor, key) ||

src/def/interfaces.ts

@@ -119,10 +119,14 @@ export type DoRegisterConfig<
 export interface CommandRegisterConfig<D extends string = string> {
   def: D;
   desc?: string;
-  config?: Command.Config;
+  config?: CommandConfigExtended;
   putOptions?: CommandPutConfig<keyof CommandPutConfigMap>[];
 }
 
+export interface CommandConfigExtended extends Command.Config {
+  empty?: boolean;
+}
+
 export interface CommandOptionConfig {
   name: string;
   desc: string;

src/register.ts

@@ -269,20 +269,22 @@ export function KoishiPlugin<T = any>(
             for (const commandDef of commandDefs) {
               command = commandDef(command) || command;
             }
-            if (!commandData.putOptions) {
-              command.action((argv: Argv, ...args: any[]) =>
-                this[methodKey](argv, ...args),
-              );
-            } else {
-              for (const _optionToRegister of commandData.putOptions) {
-                this._preRegisterCommandActionArg(_optionToRegister, command);
-              }
-              command.action((argv: Argv, ...args: any[]) => {
-                const params = commandData.putOptions.map((o) =>
-                  this._getCommandActionArg(o, argv, args),
+            if (!commandData.config?.empty) {
+              if (!commandData.putOptions) {
+                command.action((argv: Argv, ...args: any[]) =>
+                  this[methodKey](argv, ...args),
                 );
-                return this[methodKey](...params);
-              });
+              } else {
+                for (const _optionToRegister of commandData.putOptions) {
+                  this._preRegisterCommandActionArg(_optionToRegister, command);
+                }
+                command.action((argv: Argv, ...args: any[]) => {
+                  const params = commandData.putOptions.map((o) =>
+                    this._getCommandActionArg(o, argv, args),
+                  );
+                  return this[methodKey](...params);
+                });
+              }
             }
             break;
           case 'route':