add @If

package-lock.json

@@ -14,7 +14,7 @@
         "koishi-decorators": "^1.1.1",
         "lodash": "^4.17.21",
         "reflect-metadata": "^0.1.13",
-        "schemastery-gen": "^3.1.0",
+        "schemastery-gen": "^3.1.1",
         "typed-reflector": "^1.0.9"
       },
       "devDependencies": {
@@ -5786,9 +5786,9 @@
       "peer": true
     },
     "node_modules/schemastery-gen": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/schemastery-gen/-/schemastery-gen-3.1.0.tgz",
-      "integrity": "sha512-rVvv/c47aKU40f49+MWiM/anoZoKgo6+54jn4XL3frren/KISwklsJ9EstkVwUGeGiwxekP4ZNlWGS/3k0n+Aw==",
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/schemastery-gen/-/schemastery-gen-3.1.1.tgz",
+      "integrity": "sha512-zwNQR9VL8o0QE9kDN6I0y9c7kqdGxolVAdJqn6FVW2epW8CyVY+h1gMkAvABvP0gT3Aj/fATNj0cG+ampTgMkw==",
       "dependencies": {
         "lodash": "^4.17.21",
         "reflect-metadata": "^0.1.13",
@@ -11198,9 +11198,9 @@
       "peer": true
     },
     "schemastery-gen": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/schemastery-gen/-/schemastery-gen-3.1.0.tgz",
-      "integrity": "sha512-rVvv/c47aKU40f49+MWiM/anoZoKgo6+54jn4XL3frren/KISwklsJ9EstkVwUGeGiwxekP4ZNlWGS/3k0n+Aw==",
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/schemastery-gen/-/schemastery-gen-3.1.1.tgz",
+      "integrity": "sha512-zwNQR9VL8o0QE9kDN6I0y9c7kqdGxolVAdJqn6FVW2epW8CyVY+h1gMkAvABvP0gT3Aj/fATNj0cG+ampTgMkw==",
       "requires": {
         "lodash": "^4.17.21",
         "reflect-metadata": "^0.1.13",

package.json

@@ -53,7 +53,7 @@
     "koishi-decorators": "^1.1.1",
     "lodash": "^4.17.21",
     "reflect-metadata": "^0.1.13",
-    "schemastery-gen": "^3.1.0",
+    "schemastery-gen": "^3.1.1",
     "typed-reflector": "^1.0.9"
   },
   "jest": {

src/base-plugin.ts

@@ -5,5 +5,5 @@ export class BasePlugin<C, PC = Partial<C>> {
   constructor(protected ctx: Context, config: PC) {}
 
   @InjectConfig()
-  protected config: C;
+  config: C;
 }

src/decorators.ts

@@ -2,6 +2,7 @@ import 'reflect-metadata';
 import { App, Context, Selection } from 'koishi';
 import { Metadata } from './meta/metadata.decorators';
 import {
+  Condition,
   KoishiAddUsingList,
   KoishiPartialUsing,
   KoishiServiceInjectSym,
@@ -120,3 +121,6 @@ export function UsingService(
     }
   };
 }
+
+export const If = <T>(func: Condition<boolean, T>): MethodDecorator =>
+  Metadata.append('KoishiIf', func);

src/def/constants.ts

 // metadatas
 import { Context } from 'koishi';
-import { ProvideDefinition, SystemInjectFun } from './interfaces';
+import { Condition, ProvideDefinition, SystemInjectFun } from './interfaces';
 
 export const KoishiServiceInjectSym = 'KoishiServiceInjectSym';
 export const KoishiServiceInjectSymKeys = 'KoishiServiceInjectSymKeys';
@@ -18,6 +18,7 @@ export interface MetadataArrayMap {
   KoishiSystemInjectSymKeys: string;
   KoishiAddUsingList: keyof Context.Services;
   KoishiPartialUsing: keyof Context.Services;
+  KoishiIf: Condition<boolean>;
 }
 
 export interface MetadataMap {

src/def/interfaces.ts

@@ -15,3 +15,9 @@ export interface ProvideOptions {
 export interface ProvideDefinition extends ProvideOptions {
   serviceName: keyof Context.Services;
 }
+
+export type Condition<R, T = any> = (
+  o: T,
+  config: T extends { config: infer C } ? C : any,
+  ctx: Context,
+) => R;

src/register.ts

@@ -113,6 +113,13 @@ export function DefinePlugin<T = any>(
           methodKey,
           false,
         );
+        const conditions = reflector.getArray('KoishiIf', this, methodKey);
+        if (
+          conditions.some(
+            (condition) => !condition(this, this.__config as any, this.__ctx),
+          )
+        )
+          return;
         const partialUsing = reflector.getArray(
           KoishiPartialUsing,
           this,

tests/if.spec.ts

+import { DefinePlugin } from '../src/register';
+import { OnGuild, UseCommand } from 'koishi-decorators';
+import { BasePlugin } from '../dist';
+import { If } from '../src/decorators';
+import { App } from 'koishi';
+
+@DefinePlugin()
+class MyPlugin extends BasePlugin<{ foo: boolean; bar: boolean }> {
+  @If<MyPlugin>((o, config, ctx) => config.foo)
+  @UseCommand('foo')
+  foo() {
+    return 'foo';
+  }
+
+  @If<MyPlugin>((o, config, ctx) => config.bar)
+  @UseCommand('bar')
+  bar() {
+    return 'bar';
+  }
+}
+
+describe('It should register conditionally', () => {
+  it('register command on condition', async () => {
+    const app = new App();
+    app.plugin(MyPlugin, { foo: true, bar: false });
+    await app.start();
+    const commandFoo = app.command('foo');
+    const commandBar = app.command('bar');
+    expect(await commandFoo.execute({})).toBe('foo');
+    expect(await commandBar.execute({})).toBeFalsy();
+  });
+});