allow arg def in put param

src/decorators/decorators.ts

@@ -184,7 +184,8 @@ export const PutArgv = (field?: keyof Argv) =>
   field ? CommandPut.decorate('argvField', field) : CommandPut.decorate('argv');
 export const PutSession = (field?: keyof Session) =>
   field ? CommandPut.decorate('sessionField', field) : PutArgv('session');
-export const PutArg = (i: number) => CommandPut.decorate('arg', i);
+export const PutArg = (index: number, decl?: Argv.Declaration) =>
+  CommandPut.decorate('arg', { index, decl });
 export const PutArgs = () => CommandPut.decorate('args');
 export const PutOption = (
   name: string,

src/def/interfaces.ts

@@ -159,3 +159,8 @@ export interface CommandLocaleDef extends Store {
   options?: Dict<string>;
   messages?: Store;
 }
+
+export interface CommandArgDef {
+  index: number;
+  decl?: Argv.Declaration;
+}

src/registry/registries/command-put.ts

 import { Argv, Command, Context, FieldCollector, Session, User } from 'koishi';
 import {
+  CommandArgDef,
   CommandOptionConfig,
   GenerateMappingStruct,
   KoishiCommandPutDef,
@@ -17,7 +18,7 @@ import {
 export namespace CommandPut {
   export interface ConfigMap {
     args: void;
-    arg: number;
+    arg: CommandArgDef;
     argv: void;
     argvField: keyof Argv;
     option: CommandOptionConfig;
@@ -45,9 +46,13 @@ export namespace CommandPut {
   );
 
   preRegistry.extend('arg', (data, cmd, ctx, nativeType) => {
-    const arg = cmd._arguments[data];
+    const arg = cmd._arguments[data.index];
     if (arg) {
       applyNativeTypeToArg(arg, nativeType);
+    } else if (data.decl) {
+      const decl = { ...data.decl };
+      applyNativeTypeToArg(decl, nativeType);
+      cmd._arguments[data.index] = decl;
     }
   });
 
@@ -81,7 +86,7 @@ export namespace CommandPut {
   >();
 
   registry.extend('args', (data, argv, args) => args);
-  registry.extend('arg', (data, argv, args) => args[data]);
+  registry.extend('arg', (data, argv, args) => args[data.index]);
   registry.extend('argv', (data, argv, args) => argv);
   registry.extend('argvField', (data, argv, args) => argv[data]);
   registry.extend('option', (data, argv, args) => argv.options[data.name]);

src/utility/native-type-mapping.ts

 import { Argv } from 'koishi';
 
 // eslint-disable-next-line @typescript-eslint/ban-types
-const nativeTypeMapping = new Map<Function, Argv.Type>();
+export const nativeTypeMapping = new Map<Function, Argv.Type>();
 nativeTypeMapping.set(String, 'string');
 nativeTypeMapping.set(Number, 'number');
 nativeTypeMapping.set(Boolean, 'boolean');