File Utilities Library

A lightweight, zero-dependency utility library for file operations, MIME type detection, and image validation.

🌐 Created by FrontWars - Professional developer tools and resources 🖼️ Need image optimization? Visit MelhorarImagem.net - Free online image converter and optimizer

Features

✨ MIME Type Detection - Automatically detect MIME types from file extensions
🖼️ Image Validation - Check if files are images
📏 File Size Validation - Validate files against size limits
📊 Human-Readable Formatting - Convert bytes to KB, MB, GB
🎯 Zero Dependencies - Lightweight and fast
📘 TypeScript Support - Full TypeScript definitions included

Installation

npm install @frontwarsio/file-utils

Quick Start

const { getMimeType, isImage, formatFileSize } = require('@frontwarsio/file-utils');

// Get MIME type
console.log(getMimeType('photo.jpg')); // 'image/jpeg'
console.log(getMimeType('document.pdf')); // 'application/pdf'

// Check if file is an image
console.log(isImage('photo.png')); // true
console.log(isImage('document.txt')); // false

// Format file size
console.log(formatFileSize(1024)); // '1.00 KB'
console.log(formatFileSize(1048576)); // '1.00 MB'

API Reference

getMimeType(input)

Get the MIME type for a given file extension or filename.

Parameters:

• input (string): File extension or filename

Returns: string | null - The MIME type or null if not found

Example:

getMimeType('jpg')        // 'image/jpeg'
getMimeType('photo.png')  // 'image/png'
getMimeType('unknown')    // null

getExtension(filename)

Extract the file extension from a filename or path.

Parameters:

• filename (string): The filename or path

Returns: string - The file extension (lowercase, without dot)

Example:

getExtension('photo.jpg')           // 'jpg'
getExtension('/path/to/file.PDF')   // 'pdf'

isImage(filename)

Check if a file is an image based on its extension.

Parameters:

• filename (string): The filename or extension to check

Returns: boolean - True if the file is an image

Example:

isImage('photo.jpg')      // true
isImage('document.pdf')   // false

validateFileSize(sizeInBytes, maxSizeInMB)

Validate if a file size is within the specified limit.

Parameters:

• sizeInBytes (number): File size in bytes
• maxSizeInMB (number): Maximum allowed size in megabytes

Returns: boolean - True if file size is within limit

Example:

validateFileSize(1024 * 1024, 5)      // true (1MB < 5MB)
validateFileSize(10 * 1024 * 1024, 5) // false (10MB > 5MB)

formatFileSize(bytes, decimals)

Format file size to a human-readable string.

Parameters:

• bytes (number): File size in bytes
• decimals (number, optional): Number of decimal places (default: 2)

Returns: string - Formatted file size

Example:

formatFileSize(1024)       // '1.00 KB'
formatFileSize(1048576)    // '1.00 MB'
formatFileSize(1536, 1)    // '1.5 KB'

Supported File Types

The library supports 50+ file types including:

• Images: JPG, PNG, GIF, WebP, SVG, BMP, ICO, TIFF
• Documents: PDF, DOC, DOCX, XLS, XLSX, PPT, PPTX
• Text: TXT, HTML, CSS, JS, JSON, XML, Markdown
• Archives: ZIP, RAR, 7Z, TAR, GZ
• Audio: MP3, WAV, OGG, FLAC
• Video: MP4, AVI, MOV, WMV, WebM

Use Cases

• 📤 File Upload Validation - Validate file types and sizes before upload
• 🎨 Image Processing - Filter and process image files (check out MelhorarImagem.net for online image optimization)
• 📁 File Management Systems - Organize and categorize files
• 🔍 Content Type Detection - Serve files with correct headers
• 💾 Storage Management - Calculate and display storage usage

TypeScript Support

This library includes TypeScript definitions out of the box:

import { getMimeType, isImage, formatFileSize } from '@frontwarsio/file-utils';

const mimeType: string | null = getMimeType('photo.jpg');
const isImg: boolean = isImage('photo.png');
const size: string = formatFileSize(1024);

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT © FrontWars Team

Links

• 🌐 FrontWars: frontwarsio.org - Developer tools and resources
• 🖼️ MelhorarImagem: melhorarimagem.net - Free online image converter and optimizer
• 📦 NPM Package: @frontwarsio/file-utils
• 🐛 Report Issues: GitHub Issues
• 📚 More Tools: Visit FrontWars for more developer resources

Made with ❤️ by FrontWars | Image Tools: MelhorarImagem.net