JS → TS/TSX Converter CLI

A CLI tool to convert JavaScript (JS/JSX) files to fully TypeScript-compliant TS/TSX files.

This tool automatically:

• Adds type annotations for variables and function parameters
• Converts destructured function parameters to params: any with destructuring inside the function
• Skips type annotations on for...in and for...of loop variables
• Infers basic types for literals, arrays, and objects
• Detects JSX in files and outputs .tsx files
• Removes .js, .jsx, .ts, .tsx extensions from import statements

GitHub

https://github.com/sivaprasath2004/js-to-ts-converter

Features

• ✅ Converts JS/JSX files to TS/TSX
• ✅ Automatically infers types for variables
• ✅ Fixes destructured function parameters
• ✅ Fully TypeScript-compliant output
• ✅ Preserves JSX when present
• ✅ Cleans import statements (removes file extensions)

Installation

Install globally via npm:

npm install -g js-to-ts-converter-cli

Or test locally:

npm link

Usage

Convert a single file:

js-to-ts-converter ./src/utils.js

Convert a folder:

js-to-ts-converter ./src

Output files are generated in the tsConverter folder inside the source directory.

Examples

JS File: utils.js

function add({ a, b }) {
  return a + b;
}

const multiply = (x, y) => x * y;

import App from './App.js';

Converted TS File: tsConverter/utils.ts

function add(params: any): any {
  const { a, b } = params;
  return a + b;
}

const multiply = (x: any, y: any): any => x * y;

import App from './App';

Notes

• Detects JSX automatically: converts .js to .tsx if JSX is present
• Works with .js, .jsx, .ts, .tsx files
• Skips folders like node_modules, public, web_pack, .erb