feat(common): add required file validation

ensure ParseFilePipe throws an error when a file is required but was not passed

Author: thiagomini

packages/common/pipes/file/parse-file-options.interface.ts

@@ -5,5 +5,9 @@ export interface ParseFileOptions {
   validators?: FileValidator[];
   errorHttpStatusCode?: ErrorHttpStatusCode;
   exceptionFactory?: (error: string) => any;
+
+  /**
+   * Defines if file parameter is optional. Default is false.
+   */
   fileIsOptional?: boolean;
 }

packages/common/pipes/file/parse-file.pipe.ts

@@ -20,24 +20,31 @@ import { ParseFileOptions } from './parse-file-options.interface';
 export class ParseFilePipe implements PipeTransform<any> {
   protected exceptionFactory: (error: string) => any;
   private readonly validators: FileValidator[];
+  private readonly fileIsOptional: boolean;
 
   constructor(@Optional() options: ParseFileOptions = {}) {
     const {
       exceptionFactory,
       errorHttpStatusCode = HttpStatus.BAD_REQUEST,
       validators = [],
+      fileIsOptional,
     } = options;
 
     this.exceptionFactory =
       exceptionFactory ||
       (error => new HttpErrorByCode[errorHttpStatusCode](error));
 
     this.validators = validators;
+    this.fileIsOptional = fileIsOptional ?? false;
   }
 
   async transform(value: any): Promise<any> {
     if (isUndefined(value)) {
-      return value;
+      if (this.fileIsOptional) {
+        return value;
+      }
+
+      throw this.exceptionFactory('File is required');
     }
 
     if (this.validators.length) {

packages/common/test/pipes/file/parse-file.pipe.spec.ts

@@ -133,5 +133,22 @@ describe('ParseFilePipe', () => {
         );
       });
     });
+
+    describe('when file is not optional', () => {
+      beforeEach(() => {
+        parseFilePipe = new ParseFilePipe({
+          validators: [new AlwaysInvalidValidator({})],
+          fileIsOptional: false,
+        });
+      });
+
+      it('should throw an error if no file is provided', async () => {
+        const requestFile = undefined;
+
+        await expect(parseFilePipe.transform(requestFile)).to.be.rejectedWith(
+          BadRequestException,
+        );
+      });
+    });
   });
 });