File Type Validator (TypeScript)

A lightweight TypeScript utility to validate uploaded file content using its buffer. Ensures that the actual content type (magic number) of the file matches its declared file extension.

✨ Features

• ✅ Detects common image, document, audio, and video types
• ✅ Validates ZIP-based formats like .docx, .xlsx, .pptx
• ✅ Checks for renamed/misleading file extensions
• ✅ Useful for uploads, security, and validation middleware
• ✅ No external file-type libraries

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📦 Installation

npm install file-type-validator-ts

NPM package: file-type-validator-ts

🚀 Usage

• Validate a file uploaded from a form

Use with Express & Multer:

import { validateFileBuffer } from "./src/validator";

app.post("/upload", upload.single("file"), (req, res) => {
  const result = validateFileBuffer(req.file.buffer, req.file.originalname);
  res.json(result);
});

🧪 Supported File Types

📄 Document Files

• pdf
• doc, docx
• dot, dotx
• rtf
• txt, log, csv, tsv, sql, xml, json, ps, tex, md, yml
• ppt, pptx, pps, ppsx
• xls, xlsx, xlsm, xlt, xltx, xltm
• odt, ods
• epub, mobi, azw, azw3
• indd, wps, wpd, psd, ai

🖼 Image Files

• jpg, jpeg, png, bmp, gif, webp, ico, svg, heic, heif

🎧 Audio Files

• mp3, m4a, aac, ogg

🎥 Video Files

• mp4, mov, m4v, webm, wmv, avi, 3gp, 3g2

📦 Compressed & Archive Files

• zip, rar, gz, 7z, tar, deb, apk, jar

🗃 Database Files

• sqlite, db, mdb

🧪 Code Files

• js, ts, php, sh, patch

💻 Executables

• exe