test(sample): add file upload e2e test

add test using file parse pipe

sample/29-file-upload/e2e/app/app.e2e-spec.ts

@@ -1,7 +1,6 @@
 import { INestApplication } from '@nestjs/common';
 import { Test } from '@nestjs/testing';
 import { readFileSync } from 'fs';
-import { join } from 'path';
 import * as request from 'supertest';
 import { AppModule } from '../../src/app.module';
 
@@ -30,6 +29,28 @@ describe('E2E FileTest', () => {
       });
   });
 
+  it('should allow for file uploads that pass validation', async () => {
+    return request(app.getHttpServer())
+      .post('/file/pass-validation')
+      .attach('file', './package.json')
+      .field('name', 'test')
+      .expect(201)
+      .expect({
+        body: {
+          name: 'test',
+        },
+        file: readFileSync('./package.json').toString(),
+      });
+  });
+
+  it('should throw for file uploads that do not pass validation', async () => {
+    return request(app.getHttpServer())
+      .post('/file/fail-validation')
+      .attach('file', './package.json')
+      .field('name', 'test')
+      .expect(400);
+  });
+
   afterAll(async () => {
     await app.close();
   });

sample/29-file-upload/src/app.controller.ts

@@ -2,6 +2,7 @@ import {
   Body,
   Controller,
   Get,
+  ParseFilePipeBuilder,
   Post,
   UploadedFile,
   UseInterceptors,
@@ -31,4 +32,42 @@ export class AppController {
       file: file.buffer.toString(),
     };
   }
+
+  @UseInterceptors(FileInterceptor('file'))
+  @Post('file/pass-validation')
+  uploadFileAndPassValidation(
+    @Body() body: SampleDto,
+    @UploadedFile(
+      new ParseFilePipeBuilder()
+        .addFileTypeValidator({
+          fileType: 'json',
+        })
+        .build(),
+    )
+    file: Express.Multer.File,
+  ) {
+    return {
+      body,
+      file: file.buffer.toString(),
+    };
+  }
+
+  @UseInterceptors(FileInterceptor('file'))
+  @Post('file/fail-validation')
+  uploadFileAndFailValidation(
+    @Body() body: SampleDto,
+    @UploadedFile(
+      new ParseFilePipeBuilder()
+        .addFileTypeValidator({
+          fileType: 'jpg',
+        })
+        .build(),
+    )
+    file: Express.Multer.File,
+  ) {
+    return {
+      body,
+      file: file.buffer.toString(),
+    };
+  }
 }