typescript-to-javascript

A CLI tool that converts TypeScript projects to plain JavaScript by stripping type annotations and rewriting import extensions. Uses Babel to transpile .ts → .js and .tsx → .jsx, then runs a Claude Code agent to clean up config files in the output directory.

Install

npm i -g typescript-to-javascript

Requires Bun to be installed on your system.

Usage

Run from the root of any TypeScript project:

tsx-js [source-dir] [output-dir]

| Argument | Default | Description | |---|---|---| | source-dir | client | Directory containing TypeScript source files | | output-dir | <source-dir>-js | Directory where JavaScript output is written |

Examples

# Convert ./client → ./client-js
tsx-js

# Convert ./src → ./src-js
tsx-js src

# Convert ./app → ./app-output (custom output name)
tsx-js app app-output

What it does

1. Transpiles .ts files → .js using @babel/preset-typescript (strips all type annotations)
2. Transpiles .tsx files → .jsx using @babel/preset-typescript + @babel/plugin-syntax-jsx (preserves JSX, strips types)
3. Rewrites relative imports — updates .ts/.tsx extensions in import statements to their .js/.jsx equivalents
4. Runs a Claude Code agent to copy and update non-TypeScript project files (package.json, config files, etc.) in the output directory — removing TS-only deps and adjusting scripts for JavaScript

The Claude Code post-conversion step requires the claude CLI to be available. If it is not found, the step is skipped and a warning is printed.

Requirements

• Bun runtime
• Claude Code CLI (claude on PATH) — optional, for the config cleanup step

Local development

bun install
bun run convert