add empty file check and tests for the same

packages/common/src/controllers/file-upload.controller.ts

@@ -51,6 +51,13 @@ export class FileUploadController {
     file?: { url: string } | undefined;
   }> {
     try {
+      // file.size is an added attribute that comes from MultipartFile Interface defined in file-upload.interface
+      if (file.buffer.length === 0) {
+        return {
+          statusCode: 400,
+          message: 'empty file uploads are not allowed'
+        }
+      }
       const fileUploadRequestDto = new FileUploadRequestDTO();
       fileUploadRequestDto.file = file;
       fileUploadRequestDto.destination = destination;

packages/common/src/interceptors/file-upload.interceptor.ts

@@ -81,6 +81,8 @@ export function FastifyFileInterceptor(
       next: CallHandler,
     ): Promise<Observable<any>> {
       const ctx = context.switchToHttp();
+      const request = ctx.getRequest();
+      request.raw = request.raw || request;
 
       await new Promise<void>((resolve, reject) =>
         this.multer.single(fieldName)(

packages/common/test/app.e2e-spec.ts

@@ -21,4 +21,38 @@ describe('AppController (e2e)', () => {
       .expect(200)
       .expect('Hello World!');
   });
+
+  it('/files/upload-file (POST); for file with content', async () => {
+
+    const mockDestination = 'uploads';
+    const mockFilename = 'content.txt';
+
+    const response = await request(app.getHttpServer())
+      .post(
+        `/files/upload-file?destination=${mockDestination}&filename=${mockFilename}`,
+      )
+      .attach('file', Buffer.from('content'), mockFilename);
+
+    expect(response.body).toEqual({
+      message: 'File uploaded successfully',
+      file: { url: `${mockDestination}/${mockFilename}` },
+    });
+  });
+
+  it('/files/upload-file (POST); for empty file check', async () => {
+    const mockDestination = 'uploads';
+    const mockFilename = 'empty.txt';
+
+    const response = await request(app.getHttpServer())
+      .post(
+        `/files/upload-file?destination=${mockDestination}&filename=${mockFilename}`,
+      )
+      .attach('file', Buffer.from(''), mockFilename);
+
+
+    expect(response.body).toEqual({
+      statusCode: 400,
+      message: 'empty file uploads are not allowed',
+    });
+  });
 });