Add env validation

src/app.module.ts

@@ -4,10 +4,19 @@ import { AppService } from './app.service';
 import { ConfigModule } from '@nestjs/config';
 import { MongooseModule } from '@nestjs/mongoose';
 import { ShowsModule } from './shows/shows.module';
+import * as Joi from 'joi';
 
 @Module({
   imports: [
-    ConfigModule.forRoot(),
+    ConfigModule.forRoot({
+      validationSchema: Joi.object({
+        NODE_ENV: Joi.string()
+          .valid('development', 'production')
+          .default('development'),
+        URI: Joi.string().uri().required(),
+        PORT: Joi.number().port().default(3000),
+      }),
+    }),
     MongooseModule.forRoot(process.env.URI),
     ShowsModule,
   ],

src/main.ts

@@ -15,6 +15,6 @@ async function bootstrap() {
     logger.log("In development mode, not enabling CORS")
   }
 
-  await app.listen(process.env.PORT ?? 3000);
+  await app.listen(process.env.PORT);
 }
 bootstrap();