babel/experimental/babel-preset-env

babel-preset-env

Babel preset for all envs.

Install

$ npm install --save-dev babel-preset-env

Usage via .babelrc

Options

• targets - an object of browsers/environment versions to support (ex: chrome, node, etc).

The data for this is currently at: /data/plugins.json and being generated by /scripts/build-data.js using https://kangax.github.io/compat-table.

We would like help to make the data is correct! This just means usage/testing!

• loose - Enable "loose" transformations for any plugins in this preset that allow them (Disabled by default).
• modules - Enable transformation of ES6 module syntax to another module type (Enabled by default to "commonjs").
  • Can be false to not transform modules, or one of ["amd", "umd", "systemjs", "commonjs"]

{
  "presets": [
    ["env", {
      "targets": {
        "chrome": 52
      },
      "loose": true,
      "modules": false
    }]
  ]
}

Example

// src
export class A {}

// default is to run all transforms
{
  "presets": [
    ["env", {}]
  ]
}

// ...

var A = exports.A = function A() {
  _classCallCheck(this, A);
};

// target chrome 52
{
  "presets": [
    ["env", {
      "targets": {
        "chrome": 52
      }
    }]
  ]
}

// ...

class A {}
exports.A = A;

// target chrome 52 with webpack 2/rollup
{
  "presets": [
    ["env", {
      "targets": {
        "chrome": 52
      },
      "modules": false
    }]
  ]
}

// ...

export class A {}