@lunel/file-size-formatter

@lunel/file-size-formatter

A JavaScript utility for manipulating files: formatting sizes, compressing images, extracting metadata, encryption/decryption, folder analysis, downloading & compressing images, and format conversion.

Installation

npm install @lunel/file-size-formatter

Dependencies

• sharp for image compression (see documentation).

Features

Image Resizing

The resizeImage() function allows you to resize an image with custom dimensions and fit options, while preventing unwanted enlargements.

Example

import fs from 'fs/promises';
import { resizeImage } from '@lunel/file-size-formatter';

async function main() {
  const resizedBuffer = await resizeImage('assets/1.png', {
    width: 800,
    height: 600,
    fit: 'contain',
  });

  await fs.writeFile('assets/resized.png', resizedBuffer);
  console.log('Image successfully resized!');
}

main();

formatFileSize(bytes, decimals = 2)

Formats a size in bytes into a readable string.

const { formatFileSize } = require('@lunel/file-size-formatter');
console.log(formatFileSize(123456789, 1)); // "117.7 MB"

---

compressImage(input, options)

Compresses an image by adjusting its resolution and quality.

• input : File path or Buffer (required).
• options :
  • maxWidth : Maximum width (default: 1920).
  • maxHeight : Max height (default: 1080).
  • quality : Quality (0 to 1, default: 0.8).
  • maxSizeMB : Maximum size in MB (default: 2).
  • outputFormat : Format ('jpeg', 'png', 'webp', default: 'jpeg').

import { formatFileSize, compressImage, CompressionOptions } from '@lunel/file-size-formatter';
import fs from 'fs';

async function main() {
  const options: CompressionOptions = { maxWidth: 800, quality: 0.7 };
  const buffer = await compressImage('./image.jpg', options);
  fs.writeFileSync('./output.jpg', buffer);
  console.log(`Size: ${formatFileSize(buffer.length)}`);
}

main();

---

compressMultipleImages(inputs, options)

Compresses multiple images.

const { compressMultipleImages, formatFileSize } = require('@lunel/file-size-formatter');
const fs = require('fs');

async function compressMultiple() {
  const buffers = await compressMultipleImages(['./image1.jpg', './image2.jpg'], { maxWidth: 800 });
  buffers.forEach((buffer, i) => {
    fs.writeFileSync(`./compressed-image${i + 1}.jpg`, buffer);
    console.log(`Image ${i + 1} size: ${formatFileSize(buffer.length)}`);
  });
}
compressMultiple();

---

extractMetadata(filePath)

Extracts metadata from a file (e.g., image dimensions, MIME type, size, etc.).

import { extractMetadata } from '@lunel/file-size-formatter';

async function getMetadata() {
  const metadata = await extractMetadata('assets/1.png');
  console.log(metadata);
}

getMetadata();

---

encryptFile(filePath, password)

Encrypts a file with a password/key and generates a .enc file.

import { encryptFile } from '@lunel/file-size-formatter';
import { promises as fs } from 'fs';

async function encryptFileTest() {
  const encrypted = await encryptFile('assets/level.png', 'mySecretKey');
  await fs.writeFile('assets/encrypt/level.enc', encrypted);
}

encryptFileTest();

---

decryptFile(encryptedBuffer, password)

Decrypts a previously encrypted file and restores it to its original format.

import { decryptFile } from '@lunel/file-size-formatter';
import { promises as fs } from 'fs';

async function decryptFileTest() {
  const file = await fs.readFile('assets/encrypt/level.enc');
  const decrypted = await decryptFile(file, 'mySecretKey');
  await fs.writeFile('assets/decrypt/level.png', decrypted);
}

decryptFileTest();

---

analyzeFolder(path)

Analyzes a folder and returns statistics (total size + individual file sizes).

import { analyzeFolder, formatFileSize } from '@lunel/file-size-formatter';

async function main() {
  const stats: any = await analyzeFolder("utils");
  console.log(`Total size: ${formatFileSize(stats.totalSize)}`);
  stats.files.forEach((file: any) => console.log(`${file.name} : ${formatFileSize(file.size)}`));
}
main();

---

downloadAndCompress(url, options)

Downloads an image from a URL and compresses it according to the given options.

import { downloadAndCompress } from '@lunel/file-size-formatter';
import fs from 'fs/promises';

async function main() {
  const buffer = await downloadAndCompress('https://example.com/image.jpg', { maxWidth: 500 });
  await fs.writeFile('./compressed.jpg', buffer);
  console.log('Download and compression successful');
}
main();

---

convertFormat(filePath, format)

Converts an image from one format to another (e.g., PNG → WebP).

import { convertFormat } from '@lunel/file-size-formatter';
import fs from 'fs/promises';

async function main() {
  const buffer = await convertFormat('assets/1.png', 'webp');
  await fs.writeFile('convert.webp', buffer);
  console.log('Conversion successful');
}
main();

---

Tests

Run npm test with Jest to validate.

Contribute

Open an issue or pull request on GitHub.

License

MIT