js2coffee

2.2.0 verified Fri May 01 auth: no javascript maintenance

JavaScript to CoffeeScript compiler. v2.2.0 (latest) rewrites the 0.x series with a new Esprima-based parser, offering better JavaScript coverage. Released on npm and Bower. Key differentiator: unidirectional conversion from JS to CoffeeScript with warnings for unrepresentable patterns.

Common errors

error Cannot find module 'js2coffee' ↓

cause Package not installed

fix

npm install js2coffee

error js2coffee is not a function ↓

cause v2.x does not have a default export

fix

Use js2coffee.build() instead of trying to call js2coffee()

error require(...).js2coffee is not a function ↓

cause 0.x API does not exist in v2

fix

Update to js2coffee.build() for v2

Warnings

breaking 2.0 release rewrites API: 0.x `js2coffee.js2coffee()` no longer works ↓

fix Use `js2coffee.build()` instead of the old `js2coffee.js2coffee()`

deprecated 0.x series is deprecated. No longer supported. ↓

fix Upgrade to v2.x using the migration guide

gotcha Not all JavaScript constructs convert cleanly; result.warnings may contain warnings for unrepresentable patterns ↓

fix Check result.warnings array after conversion and handle accordingly

Install

npm install js2coffee

yarn add js2coffee

pnpm add js2coffee

Imports

js2coffee

wrong

import js2coffee from 'js2coffee' (ESM not supported)

correct

const js2coffee = require('js2coffee')

CommonJS only. Use require() or window.js2coffee for browser.

build
wrong
```
js2coffee(source)
```
correct
```
js2coffee.build(source)
```
build is the main API method returning { code, ast, map, warnings }
version
```
js2coffee.version (string)
```
Read-only property exposing library version

Quickstart

Compile JavaScript to CoffeeScript using the build method, outputting CoffeeScript code.

const js2coffee = require('js2coffee');
const source = `
var x = 1;
function hello(name) {
  console.log('Hello, ' + name);
}
hello('world');
`;
const result = js2coffee.build(source);
console.log(result.code);
// x = 1
// hello = (name) ->
//   console.log 'Hello, ' + name
// hello 'world'