added bound

BackendAcademy/src/app.controller.spec.ts

@@ -1,17 +1,20 @@
 import { Test, TestingModule } from '@nestjs/testing';
+import { INestApplication } from '@nestjs/common';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { AppModule } from './app.module';
+import request from 'supertest';
 
 describe('AppController', () => {
   let appController: AppController;
 
   beforeEach(async () => {
-    const app: TestingModule = await Test.createTestingModule({
+    const module: TestingModule = await Test.createTestingModule({
       controllers: [AppController],
       providers: [AppService],
     }).compile();
 
-    appController = app.get<AppController>(AppController);
+    appController = module.get<AppController>(AppController);
   });
 
   describe('getHello', () => {
@@ -20,3 +23,47 @@ describe('AppController', () => {
     });
   });
 });
+
+describe('Request body size limit (e2e)', () => {
+  let app: INestApplication;
+
+  beforeEach(async () => {
+    const moduleFixture: TestingModule = await Test.createTestingModule({
+      imports: [AppModule],
+    }).compile();
+
+    app = moduleFixture.createNestApplication();
+    await app.init();
+  });
+
+  afterEach(async () => {
+    await app.close();
+  });
+
+  it('should reject oversized JSON bodies with 413 Payload Too Large', async () => {
+    // Create a payload larger than the default 1MB limit
+    const oversizedPayload = { data: 'x'.repeat(2 * 1024 * 1024) }; // 2MB
+
+    const response = await request(app.getHttpServer())
+      .post('/api/test')
+      .send(oversizedPayload)
+      .expect(413);
+
+    expect(response.body).toHaveProperty('message');
+    expect(response.body.message).toContain('payload too large');
+  });
+
+  it('should accept JSON bodies within the size limit', async () => {
+    // Create a payload well within the 1MB limit
+    const validPayload = { data: 'x'.repeat(100) };
+
+    // Note: This endpoint may not exist, but the body size limit
+    // middleware should still allow the request through (possibly 404)
+    const response = await request(app.getHttpServer())
+      .post('/api/test')
+      .send(validPayload);
+
+    // Should not be 413 (Payload Too Large)
+    expect(response.status).not.toBe(413);
+  });
+});

BackendAcademy/src/main.ts

@@ -4,6 +4,7 @@ import { ConfigService } from '@nestjs/config';
 import { NestExpressApplication } from '@nestjs/platform-express';
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
 import helmet from 'helmet';
+import * as express from 'express';
 import { AppModule } from './app.module';
 
 // Application entry point: creates the Nest app, applies global
@@ -26,6 +27,14 @@ async function bootstrap() {
   // paths for monitoring tools that expect them un-prefixed).
   app.setGlobalPrefix('api', { exclude: ['health'] });
 
+  const configService = app.get(ConfigService);
+  // Enforces a maximum request body size to prevent DoS attacks from
+  // oversized payloads. Defaults to 1MB; configurable via MAX_BODY_SIZE
+  // env var (e.g., '5mb', '10mb'). Requests exceeding this limit return
+  // HTTP 413 (Payload Too Large) with a clear error message.
+  const maxBodySize = configService.get<string>('MAX_BODY_SIZE', '1mb');
+  app.use(express.json({ limit: maxBodySize }));
+
   // Global validation pipe applied to all incoming request bodies/params:
   //  - whitelist: strips properties not defined on the target DTO
   //  - transform: converts payloads into instances of their DTO classes
@@ -38,8 +47,6 @@ async function bootstrap() {
       forbidNonWhitelisted: true,
     }),
   );
-
-  const configService = app.get(ConfigService);
   // Swagger docs default to enabled unless explicitly turned off via
   // the SWAGGER_ENABLED env var.
   const swaggerEnabled = configService.get<string>('SWAGGER_ENABLED', 'true') === 'true';

BackendAcademy/tsconfig.json

@@ -18,7 +18,8 @@
     "forceConsistentCasingInFileNames": false,
     "noFallthroughCasesInSwitch": false,
     "esModuleInterop": true,
-    "resolveJsonModule": true
+    "resolveJsonModule": true,
+    "ignoreDeprecations": "6.0"
   },
   "include": ["src/**/*", "test/**/*"],
   "exclude": ["node_modules", "dist"]