@beautinique/backend-multer

A validated file-upload middleware for Express, built on top of multer - handles the upload, then checks Multer's own errors plus MIME type and size limits, reporting everything as a single structured error.

Installation

npm install @beautinique/backend-multer

express is a peer dependency - install whichever version your service already uses.

Usage

import { validateMulter } from '@beautinique/backend-multer';

app.post(
  '/products/:id/image',
  validateMulter({ type: 'single', fieldName: 'image' }),
  tryCatch(async (req, res) => {
    // req.file is validated - correct MIME type, within the size limit
    res.success({ data: req.file });
  }),
);

| Option | Default | Description | | ------------- | ----------------------------------- | ------------------------------------------------------------------------------------------------------ | | type | (required) | The Multer upload mode: 'single', 'array', 'fields', 'any', or 'none'. | | fieldName | - | Required when type is 'single' or 'array' - the form field to read files from. | | maxCount | Multer's default (Infinity) | Only used with type: 'array' - the max number of files accepted for fieldName. | | fieldsConfig| - | Required when type is 'fields' - { name, maxCount }[], one entry per form field. | | limits | Multer's own defaults | Passed straight through to multer({ limits }) (e.g. fileSize as a hard byte ceiling). | | format | Beautinique's image/video allowlist | Overrides the allowed MIME types per media kind: { IMAGE?, VIDEO?, OTHER? } (each an array of MIME strings). OTHER defaults to none allowed. | | size | Beautinique's image/video defaults | Overrides the max size per media kind, in bytes: { IMAGE?, VIDEO?, OTHER? }. OTHER defaults to 2 MB. |

Uploads always use multer's memoryStorage() - files are available as buffers on req.file/req.files, never written to disk.

Validation runs in two stages, and the first one that fails wins:

1. Multer's own errors - e.g. LIMIT_FILE_SIZE, LIMIT_UNEXPECTED_FILE, LIMIT_FILE_COUNT - mapped to field/global messages with the appropriate error code (PAYLOAD_TOO_LARGE, BAD_REQUEST, ...).
2. MIME type and size validation - every uploaded file (as determined by type) is checked against the resolved format/size allowlist, using Beautinique's own @beautinique/shared-constants image/video defaults unless overridden.

Either stage can report multiple field/global errors at once (via @beautinique/backend-classes's ErrorBuilder) before calling next(error) once, so a single response can list every problem with the request instead of failing on just the first one found.

Repository

https://github.com/Nageshwar1997/BQ-Packages

Homepage

https://github.com/Nageshwar1997/BQ-Packages

Issues

https://github.com/Nageshwar1997/BQ-Packages/issues

Author

Nageshwar Pawar

License

This package is licensed under the MIT License. See the root LICENSE file for details.