feat(common): add error messages for file validators

Author: mag123c

packages/common/pipes/file/file-type.validator.ts

@@ -20,7 +20,10 @@ export class FileTypeValidator extends FileValidator<
   FileTypeValidatorOptions,
   IFile
 > {
-  buildErrorMessage(): string {
+  buildErrorMessage(file?: IFile): string {
+    if (file?.mimetype) {
+      return `Validation failed (current file type is ${file.mimetype}, expected type is ${this.validationOptions.fileType})`;
+    }
     return `Validation failed (expected type is ${this.validationOptions.fileType})`;
   }
 

packages/common/pipes/file/max-file-size.validator.ts

@@ -17,7 +17,7 @@ export class MaxFileSizeValidator extends FileValidator<
   MaxFileSizeValidatorOptions,
   IFile
 > {
-  buildErrorMessage(): string {
+  buildErrorMessage(file?: IFile): string {
     if ('message' in this.validationOptions) {
       if (typeof this.validationOptions.message === 'function') {
         return this.validationOptions.message(this.validationOptions.maxSize);
@@ -26,6 +26,9 @@ export class MaxFileSizeValidator extends FileValidator<
       return this.validationOptions.message;
     }
 
+    if (file?.size) {
+      return `Validation failed (current file size is ${file.size}, expected size is less than ${this.validationOptions.maxSize})`;
+    }
     return `Validation failed (expected size is less than ${this.validationOptions.maxSize})`;
   }
 

packages/common/test/pipes/file/file-type.validator.spec.ts

@@ -93,5 +93,19 @@ describe('FileTypeValidator', () => {
         `Validation failed (expected type is ${fileType})`,
       );
     });
+
+    it('should include the file type in the error message when a file is provided', () => {
+      const currentFileType = 'image/png';
+      const fileType = 'image/jpeg';
+      const fileTypeValidator = new FileTypeValidator({
+        fileType,
+      });
+
+      const file = { mimetype: currentFileType } as any;
+
+      expect(fileTypeValidator.buildErrorMessage(file)).to.equal(
+        `Validation failed (current file type is ${currentFileType}, expected type is ${fileType})`,
+      );
+    });
   });
 });

packages/common/test/pipes/file/max-file-size.validator.spec.ts

@@ -60,5 +60,18 @@ describe('MaxFileSizeValidator', () => {
         `Validation failed (expected size is less than ${oneKb})`,
       );
     });
+
+    it('should include the file size in the error message when a file is provided', () => {
+      const currentFileSize = oneKb + 1;
+      const maxFileSizeValidator = new MaxFileSizeValidator({
+        maxSize: oneKb,
+      });
+
+      const file = { size: currentFileSize } as any;
+
+      expect(maxFileSizeValidator.buildErrorMessage(file)).to.equal(
+        `Validation failed (current file size is ${currentFileSize}, expected size is less than ${oneKb})`,
+      );
+    });
   });
 });