esdown

1.2.8 verified Fri May 01 auth: no javascript deprecated

An ES6+ to ES5 compiler and runtime environment, written in ES6. Version 1.2.8 is the current stable release. Allows writing programs using next-generation JavaScript features (classes, modules, etc.) and compiling them to ES5 for legacy environments. Can also be used as a runtime to execute ES6+ modules on Node.js via a REPL or direct module execution. Provides a CLI for translation with bundling and global export options. Key differentiator: includes module loading and bundling, comparable to Babel but more limited in scope and features; largely superseded by Babel and TypeScript.

Common errors

error esdown.translate is not a function ↓

cause Incorrect import: trying to import named export 'translate' directly.

fix

Use: var esdown = require('esdown'); esdown.translate(...);

error Cannot find module 'esdown' ↓

cause esdown not installed in the current project or globally.

fix

Run: npm install esdown (for local) or npm install -g esdown (for global CLI).

error Error: Unexpected token import ↓

cause Attempting to run files with import statements directly via node without esdown runtime.

fix

Use esdown main.js to run the file, or compile to ES5 first.

Warnings

deprecated esdown is effectively deprecated; consider using Babel or TypeScript for ES6+ compilation. ↓

fix Migrate to Babel (https://babeljs.io) or TypeScript (https://typescriptlang.org).

gotcha esdown does not support the full ES6 specification; see documentation for limitations. ↓

fix Check the limitations document (docs/limitations.md) for unsupported features.

breaking The API may have changed between versions; no clear changelog provided. ↓

fix Always test translation output after upgrading.

Install

npm install esdown

yarn add esdown

pnpm add esdown

Imports

esdown (default)
wrong
```
import esdown from 'esdown';
```
correct
```
var esdown = require('esdown');
```
esdown is primarily used with CommonJS require. No default ES module export exists.

translate

wrong

import { translate } from 'esdown';

correct

var esdown = require('esdown');
esdown.translate(input, options);

translate is a method on the exported object, not a named export.

CLI usage
wrong
```
esdown --compile src/main.js build/output.js
```
correct
```
esdown -i src/main.js -o build/output.js -b -r
```
CLI flags must be preceded by hyphens. Use -i for input, -o for output, -b for bundle, -r for runtime.

Quickstart

Demonstrates using esdown as a runtime to execute ES6 modules and as a compiler to produce a bundled ES5 output.

// Install globally
// npm install -g esdown

// Create a file main.js with ES6 module syntax
// main.js:
import { add } from './math.js';
console.log(add(2, 3));

// math.js:
export function add(a, b) { return a + b; }

// Run directly with esdown runtime:
// esdown main.js

// Or compile to ES5 bundle:
// esdown -i main.js -o bundle.js -b -r