refactor(nest): allow nestjs handlers to return a promise or a value (#492)

Co-authored-by: Youssef Gaber <1728215+Gabrola@users.noreply.github.com>

Author: SharkEzz

.changeset/polite-kiwis-hang.md

@@ -0,0 +1,5 @@
+---
+'@ts-rest/nest': patch
+---
+
+Allow Nest.js handlers to return non-promise responses

libs/ts-rest/core/src/lib/type-utils.ts

@@ -176,3 +176,5 @@ export type Not<B extends boolean> = {
   false: true;
   true: false;
 }[`${B}`];
+
+export type Promisable<T> = Promise<T> | T;

libs/ts-rest/nest/src/lib/ts-rest-nest-handler.ts

@@ -30,6 +30,7 @@ import {
   isAppRouteOtherResponse,
   parseJsonQueryObject,
   ServerInferResponses,
+  Promisable,
 } from '@ts-rest/core';
 import {
   JsonQuerySymbol,
@@ -145,12 +146,12 @@ export const TsRestHandler = (
 
 type NestHandlerImplementation<T extends AppRouter | AppRoute> =
   T extends AppRoute
-    ? (args: TsRestRequestShape<T>) => Promise<ServerInferResponses<T>>
+    ? (args: TsRestRequestShape<T>) => Promisable<ServerInferResponses<T>>
     : {
         [K in keyof T]: T[K] extends AppRoute
           ? (
               args: TsRestRequestShape<T[K]>,
-            ) => Promise<ServerInferResponses<T[K]>>
+            ) => Promisable<ServerInferResponses<T[K]>>
           : never;
       };
 

libs/ts-rest/nest/src/lib/ts-rest-nest.ts

@@ -3,12 +3,13 @@ import {
   AppRouter,
   Without,
   ServerInferResponses,
+  Promisable,
 } from '@ts-rest/core';
 import { TsRestRequestShape } from './ts-rest-request.decorator';
 
 type AppRouterMethodShape<T extends AppRoute> = (
   ...args: any[]
-) => Promise<ServerInferResponses<T>>;
+) => Promisable<ServerInferResponses<T>>;
 
 type AppRouterControllerShape<T extends AppRouter> = Without<
   {