Any JavaScript resource file can be transpiled to another JavaScript version using `js.Babel` which takes for argument the resource object and an optional dict of options listed below. Babel uses the [babel cli](https://babeljs.io/docs/en/babel-cli).
Hugo Pipe's Babel requires the `@babel/cli` and `@babel/core` JavaScript packages to be installed in the project or globally (`npm install -g @babel/cli@babel/core`) along with any Babel plugin(s) or preset(s) used (e.g., `npm install @babel/preset-env --save-dev`).
If you are using the Hugo Snap package, Babel and plugin(s) need to be installed locally within your Hugo site directory, e.g., `npm install @babel/cli @babel/core --save-dev` without the `-g` flag.
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## Configuration
We add the main project's `node_modules` to `NODE_PATH` when running Babel and similar tools. There are some known [issues](https://github.com/babel/babel/issues/5618) with Babel in this area, so if you have a `babel.config.js` living in a Hugo Module (and not in the project itself), we recommend using `require` to load the presets/plugins, e.g.:
```js
module.exports = {
presets: [
[
require("@babel/preset-env"),
{
useBuiltIns: "entry",
corejs: 3,
},
],
],
};
```
## Options
config
: (`string`) Path to the Babel configuration file. Hugo will, by default, look for a `babel.config.js` in your project. More information on these configuration files can be found here: [babel configuration](https://babeljs.io/docs/en/configuration).
minified
: (`bool`) Save as many bytes as possible when printing
noComments
: (`bool`) Write comments to generated output (true by default)
compact
: (`bool`) Do not include superfluous whitespace characters and line terminators. Defaults to `auto` if not set.
verbose
: (`bool`) Log everything
sourceMap
: (`string`) Output `inline` or `external` sourcemap from the babel compile. External sourcemaps will be written to the target with the output file name + ".map". Input sourcemaps can be read from js.Build and node modules and combined into the output sourcemaps.
