hugo/content/en/hugo-pipes/js.md

title	description	date	publishdate	lastmod	categories	keywords	menu	weight	sections_weight	draft
JavaScript Building	Hugo Pipes can process JavaScript files with [ESBuild](https://github.com/evanw/esbuild).	2020-07-20	2020-07-20	2020-07-20	asset management		docs parent weight pipes 45	45	45	false

Any JavaScript resource file can be transpiled and "tree shaken" using js.Build which takes for argument either a string for the filepath or a dict of options listed below.

Options

targetPath [string]

If not set, the source path will be used as the base target path. Note that the target path's extension may change if the target MIME type is different, e.g. when the source is TypeScript.

params [map or slice] {{< new-in "0.78.0" >}}

Params that can be imported as JSON in your JS files, e.g.:

{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}

And then in your JS file:

import * as params from '@params';

Note that this is meant for small data sets, e.g. config settings. For larger data, please put/mount the files into /assets and import them directly.

minify [bool]

Let js.Build handle the minification.

avoidTDZ {{< new-in "0.78.0" >}}

There is/was a bug in WebKit with severe performance issue with the tracking of TDZ checks in JavaScriptCore. Enabling this flag removes the TDZ and const assignment checks and may improve performance of larger JS codebases until the WebKit fix is in widespread use. See https://bugs.webkit.org/show_bug.cgi?id=199866

inject [slice] {{< new-in "0.81.0" >}}

This option allows you to automatically replace a global variable with an import from another file. The path names must be relative to assets. See https://esbuild.github.io/api/#inject

shims {{< new-in "0.81.0" >}}

This option allows swapping out a component with another. A common use case is to load dependencies like React from a CDN (with shims) when in production, but running with the full bundled node_modules dependency during development:

{{ $shims := dict "react" "js/shims/react.js"  "react-dom" "js/shims/react-dom.js" }}
{{ $js = $js | js.Build dict "shims" $shims }}

The shim files may look like these:

// js/shims/react.js
module.exports = window.React;

// js/shims/react-dom.js
module.exports = window.ReactDOM;

With the above, these imports should work in both scenarios:

import * as React from 'react'
import * as ReactDOM from 'react-dom';

target [string]

The language target. One of: es5, es2015, es2016, es2017, es2018, es2019, es2020 or esnext. Default is esnext.

externals [slice]

External dependencies. Use this to trim dependencies you know will never be executed. See https://esbuild.github.io/api/#external

defines [map]

Allow to define a set of string replacement to be performed when building. Should be a map where each key is to be replaced by its value.

{{ $defines := dict "process.env.NODE_ENV" `"development"` }}

format [string] {{< new-in "0.74.3" >}}

The output format. One of: iife, cjs, esm. Default is iife, a self-executing function, suitable for inclusion as a