Merge pull request nestjs#10025 from thiagomini/fix/10017-parse-file-pipe-builder

Fix/10017 parse file pipe builder

Author: kamilmysliwiec

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

@@ -5,4 +5,10 @@ export interface ParseFileOptions {
   validators?: FileValidator[];
   errorHttpStatusCode?: ErrorHttpStatusCode;
   exceptionFactory?: (error: string) => any;
+
+  /**
+   * Defines if file parameter is required.
+   * @default true
+   */
+  fileIsRequired?: boolean;
 }

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

@@ -1,9 +1,10 @@
+import { isUndefined } from '../../utils/shared.utils';
 import { Injectable, Optional } from '../../decorators/core';
 import { HttpStatus } from '../../enums';
-import { HttpErrorByCode } from '../../utils/http-error-by-code.util';
 import { PipeTransform } from '../../interfaces/features/pipe-transform.interface';
-import { ParseFileOptions } from './parse-file-options.interface';
+import { HttpErrorByCode } from '../../utils/http-error-by-code.util';
 import { FileValidator } from './file-validator.interface';
+import { ParseFileOptions } from './parse-file-options.interface';
 
 /**
  * Defines the built-in ParseFile Pipe. This pipe can be used to validate incoming files
@@ -19,22 +20,33 @@ import { FileValidator } from './file-validator.interface';
 export class ParseFilePipe implements PipeTransform<any> {
   protected exceptionFactory: (error: string) => any;
   private readonly validators: FileValidator[];
+  private readonly fileIsRequired: boolean;
 
   constructor(@Optional() options: ParseFileOptions = {}) {
     const {
       exceptionFactory,
       errorHttpStatusCode = HttpStatus.BAD_REQUEST,
       validators = [],
+      fileIsRequired,
     } = options;
 
     this.exceptionFactory =
       exceptionFactory ||
       (error => new HttpErrorByCode[errorHttpStatusCode](error));
 
     this.validators = validators;
+    this.fileIsRequired = fileIsRequired ?? true;
   }
 
   async transform(value: any): Promise<any> {
+    if (isUndefined(value)) {
+      if (this.fileIsRequired) {
+        throw this.exceptionFactory('File is required');
+      }
+
+      return value;
+    }
+
     if (this.validators.length) {
       await this.validate(value);
     }

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

@@ -116,5 +116,65 @@ describe('ParseFilePipe', () => {
         });
       });
     });
+
+    describe('when fileIsRequired is false', () => {
+      beforeEach(() => {
+        parseFilePipe = new ParseFilePipe({
+          validators: [],
+          fileIsRequired: false,
+        });
+      });
+
+      it('should pass validation if no file is provided', async () => {
+        const requestFile = undefined;
+
+        await expect(parseFilePipe.transform(requestFile)).to.eventually.eql(
+          requestFile,
+        );
+      });
+    });
+
+    describe('when fileIsRequired is true', () => {
+      beforeEach(() => {
+        parseFilePipe = new ParseFilePipe({
+          validators: [],
+          fileIsRequired: true,
+        });
+      });
+
+      it('should throw an error if no file is provided', async () => {
+        const requestFile = undefined;
+
+        await expect(parseFilePipe.transform(requestFile)).to.be.rejectedWith(
+          BadRequestException,
+        );
+      });
+
+      it('should pass validation if a file is provided', async () => {
+        const requestFile = {
+          path: 'some-path',
+        };
+
+        await expect(parseFilePipe.transform(requestFile)).to.eventually.eql(
+          requestFile,
+        );
+      });
+    });
+
+    describe('when fileIsRequired is not explicitly provided', () => {
+      beforeEach(() => {
+        parseFilePipe = new ParseFilePipe({
+          validators: [new AlwaysInvalidValidator({})],
+        });
+      });
+
+      it('should throw an error if no file is provided', async () => {
+        const requestFile = undefined;
+
+        await expect(parseFilePipe.transform(requestFile)).to.be.rejectedWith(
+          BadRequestException,
+        );
+      });
+    });
   });
 });

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

@@ -51,6 +51,18 @@ describe('E2E FileTest', () => {
       .expect(400);
   });
 
+  it('should throw when file is required but no file is uploaded', async () => {
+    return request(app.getHttpServer())
+      .post('/file/fail-validation')
+      .expect(400);
+  });
+
+  it('should allow for optional file uploads with validation enabled (fixes #10017)', () => {
+    return request(app.getHttpServer())
+      .post('/file/pass-validation')
+      .expect(201);
+  });
+
   afterAll(async () => {
     await app.close();
   });

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

@@ -42,13 +42,15 @@ export class AppController {
         .addFileTypeValidator({
           fileType: 'json',
         })
-        .build(),
+        .build({
+          fileIsRequired: false,
+        }),
     )
-    file: Express.Multer.File,
+    file?: Express.Multer.File,
   ) {
     return {
       body,
-      file: file.buffer.toString(),
+      file: file?.buffer.toString(),
     };
   }