lasso-babel-transform

Lasso.js transform that uses Babel to transpile ES6 code to ES5.

Prerequisites

This transform requires Lasso v2+

Installation

lasso 2.x/3.x, babel 7.x, lasso-babel-transform 2.x

npm install lasso-babel-transform @babel/core

lasso 2.x/3.x, babel 6.x, lasso-babel-transform 1.x

npm install lasso-babel-transform@1

Usage

By default, this plugin will look for a .babelrc while traversing up the root directory of the packages and will transpile any files that have the .js or .es6 extension. If a .babelrc file does not exist, it will attempt to look for a .babelrc-browser file. If neither of those files exist, this plugin will look in the package.json for a babel property.

You can specify different file extensions with the extensions option in the transform's config (shown below).

require('lasso').configure({
    require: {
        transforms: [
            {
                transform: 'lasso-babel-transform',
                config: {
                    extensions: ['.js', '.es6'] // Enabled file extensions. Default: ['.js', '.es6']
                }
            }
        ]
    }
});

Global babel options

Alternatively, babel options can be provided directly via the config. Note: Specifying babel options directly will cause all files to be transpiled with these options (regardless of what is specified in the package's .babelrc, .babelrc-browser, or babel property in the package.json).

require('lasso').configure({
    require: {
        transforms: [
            {
                transform: 'lasso-babel-transform',
                config: {
                    // directly specify babel options
                    babelOptions: {
                        presets: [ "@babel/preset-env" ]
                    }
                }
            }
        ]
    }
});

Configuring Babel

You will want to put a .babelrc or .babelrc-browser file at the root of each package that has any JavaScript files that should be transpiled by Babel. For example:

my-module/.babelrc:

{
    "exclude": ["excluded/**"],
    "presets": [ "@babel/preset-env" ]
}

As mentioned above, you can also opt to use the babel property to the package.json.

my-module/package.json:

{
    "name": "my-module",
    ...
    "babel": {
        // babel config goes here
    }
}

You will need to install any Babel plugins enabled in your babel config. For example:

npm install @babel/preset-env --save