Decaf JS

0.4.18 verified Fri May 01 auth: no javascript deprecated

A CoffeeScript to ES.Next transpiler that converts CoffeeScript code to modern JavaScript (ES6+). Current version 0.4.18 is released as a young project with limited feature coverage; uses the CoffeeScript compiler under the hood for parsing. Key differentiators: falls back to CoffeeScript output when ES6 transpilation is not supported, integrates with jscodeshift for code optimization. Alternative to manual refactoring or other transpilers like decaffeinate.

Common errors

error Module not found: Can't resolve 'decafjs' ↓

cause Package not installed; incorrect package name used.

fix

Run npm install decafjs and import with require('decafjs').

error TypeError: decaf.compile is not a function ↓

cause Importing the default export incorrectly with ESM syntax.

fix

Use const decaf = require('decafjs') instead of import decaf from 'decafjs'.

Warnings

gotcha Decaf may not support all CoffeeScript syntax; unsupported features fall back to original CoffeeScript output. ↓

fix Check the test suite for supported features; manually review transpiled output.

deprecated The project is no longer actively maintained; last release was 2016. ↓

fix Consider using an alternative like decaffeinate or manually rewriting code.

gotcha The npm package name is 'decafjs', not 'decaf' or 'shopify-decaf'. ↓

fix Install using `npm install decafjs`.

gotcha The package is CommonJS-only; ESM imports or TypeScript types are not available. ↓

fix Use `require()` or set up a transpilation step.

gotcha The 'compile' function's second argument is passed to recast; options may affect output formatting. ↓

fix Refer to recast documentation for valid options.

Install

npm install shopify-decaf

yarn add shopify-decaf

pnpm add shopify-decaf

Imports

decaf
wrong
```
const decaf = require('decafjs')
```
correct
```
import decaf from 'decafjs'
```
Package is CommonJS-only; default export via require is correct. ESM import may fail.
compile
wrong
```
import { compile } from 'decafjs'
```
correct
```
const { compile } = require('decafjs')
```
Named export only accessible via require; ESM named import not supported.

transform

wrong

const compile = require('decafjs').compile

correct

const decaf = require('decafjs'); decaf.compile(code)

Direct property access is fine, but destructuring is also valid.

Quickstart

Shows basic usage of decaf to transpile a CoffeeScript function to ES6.

const decaf = require('decafjs');
const coffee = `-> alert "hello world"`;
const js = decaf.compile(coffee);
console.log(js);