refactor(decorator): fix types

Author: akhil-neoito

src/decorators/log-message.decorator.ts

@@ -1,4 +1,8 @@
-import { type DescriptorFn, createDecorator } from '@/decorators/utils';
+import {
+  type DescriptorFn,
+  createDecorator,
+  type DefaultDecoratorArgs,
+} from '@/decorators/utils';
 
 interface LogMessageDecoratorArgs {
   message: string;
@@ -14,7 +18,9 @@ const descriptorFn: LogMessageDescriptor = ({ message }) => {
  * This is a sample decorator created using the `createDecorator()` method.
  * The same format can be used to create your own custom decorators.
  */
-const LogMessage = <TArgs = unknown>(args: LogMessageDecoratorArgs) => {
+const LogMessage = <TArgs extends DefaultDecoratorArgs = DefaultDecoratorArgs>(
+  args: LogMessageDecoratorArgs
+) => {
   return createDecorator<
     LogMessageDecoratorArgs,
     TArgs,

src/decorators/utils.ts

@@ -1,6 +1,9 @@
 import logger from '@/lib/logger';
 
-export type DecoratorArgs<T = unknown> = [T, string, number];
+export type DefaultDecoratorArgs = [unknown];
+export type DecoratorArgs<
+  T extends DefaultDecoratorArgs = DefaultDecoratorArgs,
+> = T extends DefaultDecoratorArgs ? [string, number] : T;
 export type DecoratorFn<TArgs extends DecoratorArgs, TReturn = void> = (
   ...args: TArgs
 ) => TReturn;
@@ -21,7 +24,11 @@ export type ContextTarget<This, TReturn> = (
  * @param descriptorArgs - Arguments for the descriptor function.
  * @returns The generated decorator function.
  */
-export function createDecorator<TFnArgs, TArgs = unknown, TReturn = void>(
+export function createDecorator<
+  TFnArgs,
+  TArgs extends DefaultDecoratorArgs = DefaultDecoratorArgs,
+  TReturn = void,
+>(
   descriptorFn: DescriptorFn<TFnArgs, TReturn>,
   descriptorArgs: TFnArgs
 ): GeneratedDecorator<any> {
@@ -45,7 +52,12 @@ export function createDecorator<TFnArgs, TArgs = unknown, TReturn = void>(
  * @param descriptorArgs - Arguments for the descriptor function.
  * @returns The generated context-aware decorator.
  */
-export function createContextDecorator<This, TReturn, TFnArgs, TArgs = unknown>(
+export function createContextDecorator<
+  This,
+  TReturn,
+  TFnArgs,
+  TArgs extends DefaultDecoratorArgs = DefaultDecoratorArgs,
+>(
   context: ClassMethodDecoratorContext<This, ContextTarget<This, TReturn>>,
   _target: ContextTarget<This, TReturn>,
   descriptorFn: DescriptorFn<TFnArgs, TReturn>,

src/modules/users/users.service.ts

@@ -3,7 +3,7 @@ import prisma from '@/lib/prisma';
 import LogMessage from '@/decorators/log-message.decorator';
 
 export default class UserService {
-  @LogMessage({ message: 'test-decorator' })
+  @LogMessage<[users]>({ message: 'test-decorator' })
   public async createUser(data: users) {
     const user = await prisma.users.create({ data });
     return user;