babel-preset-stage-1

6.24.1 verified Sat Apr 25 auth: no javascript deprecated

Babel preset that includes all stage 1 ECMAScript proposal plugins. This package is deprecated and removed in Babel 7+; stage presets were removed in favor of individual proposal plugins. Version 6.24.1 is the last stable release of the legacy Babel 6 line. Use @babel/preset-env with specific proposal plugins (e.g., @babel/plugin-proposal-xxx) instead. No longer maintained.

Common errors

error Error: Plugin/Preset files are not allowed to export objects, only functions. ↓

cause Using a Babel 6 preset with Babel 7 or vice versa.

fix

Ensure your Babel version matches the preset version. Use @babel/preset-env for Babel 7, or downgrade to Babel 6.

error Cannot find module 'babel-preset-stage-1' ↓

cause Preset not installed or not in node_modules.

fix

Run 'npm install --save-dev babel-preset-stage-1' and verify it is listed in package.json.

error ReferenceError: [BABEL] unknown: Decorators transform is necessary. ↓

cause Trying to use decorators without the proper plugin configuration.

fix

The stage-1 preset should include decorators. If not, add 'babel-plugin-transform-decorators-legacy' explicitly.

Warnings

deprecated Stage presets are removed in Babel 7. Use @babel/preset-env and individual @babel/plugin-proposal-* plugins. ↓

fix Upgrade to Babel 7 and replace 'stage-1' with specific proposal plugins like @babel/plugin-proposal-decorators, @babel/plugin-proposal-export-namespace-from, etc.

breaking Babel 6 stage presets include unstable proposals that may change or be removed in future ECMAScript specs. ↓

fix Pin exact Babel versions and test regularly with newer presets. Consider using @babel/preset-env with targeted proposals in Babel 7.

gotcha The decorator plugin in stage-1 is the legacy (stage 1) decorator proposal, which is incompatible with the stage 2 decorators in Babel 7. ↓

fix If upgrading to Babel 7, use @babel/plugin-proposal-decorators with the 'legacy' option for backward compatibility.

deprecated babel-preset-stage-1 is no longer maintained. Last version 6.24.1 dates back to 2017. ↓

fix Do not use for new projects. Migrate to Babel 7 or later.

Install

npm install babel-preset-stage-1

yarn add babel-preset-stage-1

pnpm add babel-preset-stage-1

Imports

default
wrong
```
import stage1 from 'babel-preset-stage-1'
```
correct
```
module.exports = require('babel-preset-stage-1')
```
Babel 6 presets are CommonJS modules. ESM import syntax is not supported directly. Use require() or configure in .babelrc.
babel-preset-stage-1 in .babelrc
wrong
```
{"presets": ["babel-preset-stage-1"]}
```
correct
```
{"presets": ["stage-1"]}
```
Babel resolves short preset names (without 'babel-preset-') automatically. Using the full name works but is not conventional.
babel-preset-stage-1 via Node API
wrong
```
require('babel-core').transform(code, { presets: ['stage-1'] })
```
correct
```
require('babel-core').transform(code, { presets: [require('babel-preset-stage-1')] })
```
When using Node API, you can pass either a string (resolved by Babel) or the preset object directly. Both work.

Quickstart

Shows how to install and configure Babel 6 stage-1 preset via .babelrc or Node API, enabling stage 1 proposals like decorators.

// Install: npm install --save-dev babel-preset-stage-1 babel-cli
// .babelrc
{
  "presets": ["stage-1"]
}

// Or via Node API
const babel = require('babel-core');
const result = babel.transform('class A { @decorator method() {} }', {
  presets: ['stage-1']
});
console.log(result.code);