file-lang

Deterministically detect a programming language from a file path, file name, or extension.

file-lang is a tiny utility that maps file extensions and well-known filenames to human‑readable language names.

Install

npm install file-lang

Usage

import { detectLanguage } from "file-lang";

detectLanguage("ts"); // "TypeScript"
detectLanguage(".ts"); // "TypeScript"
detectLanguage("index.ts"); // "TypeScript"
detectLanguage("/src/utils/file.ts"); // "TypeScript"
detectLanguage("Dockerfile"); // "Docker"
detectLanguage("unknown.ext"); // "Unknown"

Accepted Input

detectLanguage accepts any string representing:

• A file extension (ts, .ts)
• A file name (index.ts)
• A file path (/path/to/file.ts)
• Well-known filenames (Dockerfile, Makefile)

Invalid, empty, or unsupported inputs safely return:

"Unknown";

The function never throws.

Output

• Returns a human-readable language name (Title Case)
• Returns "Unknown" if no mapping exists

Examples:

• "TypeScript"
• "JavaScript"
• "Markdown"
• "Docker"

Contributing

Contributions are welcome, especially:

• Adding support for additional languages
• Improving test coverage

Guidelines:

• Keep changes minimal
• Follow existing naming conventions