From 32936ee270a35f52b86607f249389d19f4c16a09 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Pedersen?=
 <bjorn.erik.pedersen@gmail.com>
Date: Wed, 4 Dec 2024 13:31:45 +0100
Subject: [PATCH] Update JS docs vs Hugo v0.140

---
 content/en/functions/js/Babel.md           |   3 +-
 content/en/functions/js/Batch.md           | 324 +++++++++++++++++++++
 content/en/functions/js/Build.md           |  87 +-----
 content/en/functions/js/_common/_index.md  |  13 +
 content/en/functions/js/_common/options.md |  99 +++++++
 content/en/hugo-pipes/babel.md             |  76 -----
 content/en/hugo-pipes/js.md                | 180 +-----------
 content/en/methods/page/Resources.md       |  14 +
 8 files changed, 457 insertions(+), 339 deletions(-)
 create mode 100644 content/en/functions/js/Batch.md
 create mode 100644 content/en/functions/js/_common/_index.md
 create mode 100644 content/en/functions/js/_common/options.md
 delete mode 100755 content/en/hugo-pipes/babel.md

diff --git a/content/en/functions/js/Babel.md b/content/en/functions/js/Babel.md
index 4271cd35e3..9485b4d057 100644
--- a/content/en/functions/js/Babel.md
+++ b/content/en/functions/js/Babel.md
@@ -3,8 +3,9 @@ title: js.Babel
 description: Compiles the given JavaScript resource with Babel.
 categories: []
 keywords: []
+weight: 100
 action:
-  aliases: [babel]
+  aliases: [babel,/hugo-pipes/babel/]
   related:
     - functions/js/Build
     - functions/resources/Fingerprint
diff --git a/content/en/functions/js/Batch.md b/content/en/functions/js/Batch.md
new file mode 100644
index 0000000000..4c66e5953b
--- /dev/null
+++ b/content/en/functions/js/Batch.md
@@ -0,0 +1,324 @@
+---
+title: js.Batch
+description: Build JavaScript bundle groups with global code splitting and flexible hooks/runners setup.
+weight: 50
+categories: []
+keywords: []
+action:
+  aliases: []
+  related:
+    - functions/js/Build
+    - functions/js/Babel
+    - functions/resources/Fingerprint
+    - functions/resources/Minify
+  returnType: js.Batcher
+  signatures: ['js.Batch [ID]']
+toc: true
+---
+
+{{% note %}}
+For a runnable example of this feature, see [this test and demo repo](https://github.com/bep/hugojsbatchdemo/).
+{{% /note %}}
+
+The Batch `ID` is used to create the base directory for this batch. Forward slashes are allowed. `js.Batch` returns an object with an API with this structure:
+
+* [Group]
+  * [Script]
+    * [SetOptions]
+  * [Instance]
+    * [SetOptions]
+  * [Runner]
+    * [SetOptions]
+  * [Config]
+    * [SetOptions]
+
+
+## Group
+
+The `Group` method take an `ID` (`string`) as argument. No slashes. It returns an object with these methods:
+
+
+### Script
+
+The `Script` method takes an `ID` (`string`) as argument. No slashes. It returns an [OptionsSetter] that can be used to set [script options] for this script.
+
+```go-html-template
+{{ with js.Batch "js/mybatch" }}
+  {{ with .Group "mygroup" }}
+      {{ with .Script "myscript" }}
+          {{ .SetOptions (dict "resource" (resources.Get "myscript.js")) }}
+      {{ end }}
+  {{ end }}
+{{ end }}
+```
+
+`SetOptions` takes a [script options] map. Note that if you want the  script to be handled by a [runner], you need to set the `export` option to match what you want to pass on to the runner (default is `*`).
+
+### Instance
+
+The `Instance` method takes two `string` arguments `SCRIPT_ID` and `INSTANCE_ID`. No slashes. It returns an [OptionsSetter] that can be used to set [params options] for this instance.
+
+```go-html-template
+{{ with js.Batch "js/mybatch" }}
+  {{ with .Group "mygroup" }}
+      {{ with .Instance "myscript" "myinstance" }}
+          {{ .SetOptions (dict "params" (dict "param1" "value1")) }}
+      {{ end }}
+  {{ end }}
+{{ end }}
+```
+
+`SetOptions` takes a [params options] map. The instance options will be passed to any [runner] script in the same group as JSON.
+
+
+### Runner
+
+The `Runner` method takes an `ID` (`string`) as argument. No slashes. It returns an [OptionsSetter] that can be used to set [script options] for this runner.
+
+```go-html-template
+{{ with js.Batch "js/mybatch" }}
+  {{ with .Group "mygroup" }}
+      {{ with .Runner "myrunner" }}
+          {{ .SetOptions (dict "resource" (resources.Get "myrunner.js")) }}
+      {{ end }}
+  {{ end }}
+{{ end }}
+```
+
+`SetOptions` takes a [script options] map.
+
+that will receive a data structure with all instances for that group with a live binding of the [JavaScript import] of the defined `export`.
+
+
+The runner script's export must be a function that takes one argument, the group data structure. An example of a group data structure as JSON is:
+
+```json
+{
+    "id": "leaflet",
+    "scripts": [
+        {
+            "id": "mapjsx",
+            "binding": JAVASCRIPT_BINDING,
+            "instances": [
+                {
+                    "id": "0",
+                    "params": {
+                        "c": "h-64",
+                        "lat": 48.8533173846729,
+                        "lon": 2.3497416090232535,
+                        "r": "map.jsx",
+                        "title": "Cathédrale Notre-Dame de Paris",
+                        "zoom": 23
+                    }
+                },
+                {
+                    "id": "1",
+                    "params": {
+                        "c": "h-64",
+                        "lat": 59.96300872062237,
+                        "lon": 10.663529183196863,
+                        "r": "map.jsx",
+                        "title": "Holmenkollen",
+                        "zoom": 3
+                    }
+                }
+            ]
+        }
+    ]
+}
+```
+
+Below is an example of a runner script that uses React to render elements. Note that the export (`default`) must match the `export` option in the [script options] (`default` is the default value for runner scripts) (runnable versions of examples on this page can be found at [js.Batch Demo Repo]):
+
+
+```js
+import * as ReactDOM from 'react-dom/client';
+import * as React from 'react';
+
+export default function Run(group) {
+	console.log('Running react-create-elements.js', group);
+	const scripts = group.scripts;
+	for (const script of scripts) {
+		for (const instance of script.instances) {
+			/* This is a convention in this project. */
+			let elId = `${script.id}-${instance.id}`;
+			let el = document.getElementById(elId);
+			if (!el) {
+				console.warn(`Element with id ${elId} not found`);
+				continue;
+			}
+			const root = ReactDOM.createRoot(el);
+			const reactEl = React.createElement(script.binding, instance.params);
+			root.render(reactEl);
+		}
+	}
+}
+```
+
+
+
+### Config
+
+Returns an [OptionsSetter] that can be used to set [build options] for the batch.
+
+These are mostly the same as for [js.Build], but note that:
+
+* `targetPath` is set automatically (there may be multiple outputs).
+* `format` must be `esm`, currently the only format supporting [code splitting].
+* `params` will be available in th `@params/config` namespace in the scripts. This way you can import both the [script] or [runner] params and the [config] params with:
+
+```js
+import * as params from "@params";
+import * as config from "@params/config";
+```
+
+Setting the `Config` for a batch can be done from any template (including shortcode templates), but will only be set once (the first will win):
+
+```go-html-template
+{{ with js.Batch "js/mybatch" }}
+  {{ with .Config }}
+       {{ .SetOptions (dict
+        "target" "es2023"
+        "format" "esm"
+        "jsx" "automatic"
+        "loaders" (dict ".png" "dataurl")
+        "minify" true
+        "params" (dict "param1" "value1")
+        )
+      }}
+  {{ end }}
+{{ end }}
+```
+
+## Options
+
+### Build Options
+
+format
+: (`string`) Currently only `esm` is supported in [ESBuild's code splitting].
+
+{{% include "./_common/options.md" %}}
+
+### Script Options
+
+resource
+: The resource to build. This can be a file resource or a virtual resource.
+
+export
+: The export to bind the runner to. Set it to `*` to export the [entire namespace](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import#namespace_import). Default is `default` for [runner] scripts and `*` for other [scripts](#script).
+
+importContext
+: An additional context for resolving imports. Hugo will always check this one first before falling back to `assets` and `node_modules`. A common use of this is to resolve imports inside a page bundle. See [import context](#import-context).
+
+params
+: A map of parameters that will be passed to the script as JSON. These gets bound to the `@params` namespace:
+```js
+import * as params from '@params';
+```
+
+### Script Options
+
+### Params Options
+
+params
+: A map of parameters that will be passed to the script as JSON. 
+
+### Import Context
+
+Hugo will, by default, first try to resolve any import in [assets](/introduction/#asset-directory) and, if not found, let [ESBuild] resolve it (e.g. from `node_modules`). The  `importContext` option can be used to set the first context for resolving imports. A common use of this is to resolve imports inside a [page bundle](/content-management/page-bundles/).
+
+```go-html-template
+{{ $common := resources.Match "/js/headlessui/*.*" }}
+{{ $importContext := (slice $.Page ($common.Mount "/js/headlessui" ".")) }}
+```
+
+You can pass any object that implements [Resource.Get](/methods/page/resources/#get). Pass a slice to set multiple contexts.
+
+The example above uses [`Resources.Mount`] to resolve a folder inside `assets` relative to the page bundle.
+
+### OptionsSetter
+
+An `OptionsSetter` is a special object that is returned once only. This means that you should wrap it with [with]:
+
+```go-html-template
+{{ with .Script "myscript" }}
+    {{ .SetOptions (dict "resource" (resources.Get "myscript.js"))}}
+{{ end }}
+```
+
+## Build
+
+The `Build` method returns an object with the following structure:
+
+* Groups (map)
+  * [`Resources`]
+
+Eeach [`Resource`] will be of media type `application/javascript` or `text/css`.
+
+ In a template you would typically hande one group with a given `ID` (e.g. scripts for the current section). Because of the concurrent build, this needs to be done in a [`templates.Defer`] block:
+
+```go-html-template
+{{ $group := .group }}
+{{ with (templates.Defer (dict "key" $group "data" $group )) }}
+  {{ with (js.Batch "js/mybatch") }}
+    {{ with .Build }}
+      {{ with index .Groups $ }}
+        {{ range . }}
+          {{ $s := . }}
+          {{ if eq $s.MediaType.SubType "css" }}
+            <link href="{{ $s.RelPermalink }}" rel="stylesheet" />
+          {{ else }}
+            <script src="{{ $s.RelPermalink }}" type="module"></script>
+          {{ end }}
+        {{ end }}
+      {{ end }}
+  {{ end }}
+{{ end }}
+```
+
+
+## Known Issues
+
+In the official documentation for [ESBuild's code splitting], there's a warning note in the header. The two issues are:
+
+* Only `esm` output format is supported. This means that it will not work for old browsers. See [caniuse](https://caniuse.com/?search=ESM).
+* There's a known import ordering issue.
+
+We have not seen the ordering issue as a problem during our [extensive testing](https://github.com/bep/hugojsbatchdemo) of this new feature with different libraries. There are two main cases:
+
+1. Undefined execution order of imports, see [this comment](https://github.com/evanw/esbuild/issues/399#issuecomment-1458680887)
+2. Only one execution order of imports, see [this comment](https://github.com/evanw/esbuild/issues/399#issuecomment-735355932)
+
+Many would say that both of the above are [code smells](https://en.wikipedia.org/wiki/Code_smell). The first one has a simple workaround in Hugo. Define the import order in its own script and make sure it gets passed early to ESBuild, e.g. by putting it in a script goup with a name that comes early in the alphabet.
+
+```js
+import './lib2.js';
+import './lib1.js';
+
+console.log('entrypoints-workaround.js');
+
+```
+
+[build options]: #build-options
+[`Resource`]: https://gohugo.io/methods/resource/
+[`Resources`]: /methods/page/resources/
+[`Resources.Mount`]: /methods/page/resources/#mount
+[`templates.Defer`]: /functions/templates/defer/
+[code splitting]: https://esbuild.github.io/api/#splitting
+[config]: #config
+[ESBuild's code splitting]: https://esbuild.github.io/api/#splitting
+[ESBuild]: https://github.com/evanw/esbuild
+[group]: #group
+[instance]: #instance
+[JavaScript import]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import
+[js.Batch Demo Repo]: https://github.com/bep/hugojsbatchdemo/
+[js.Build]: https://gohugo.io/hugo-pipes/js/#options
+[map]: https://gohugo.io/functions/collections/dictionary/
+[OptionsSetter]: #optionssetter
+[page bundles]: https://gohugo.io/content-management/page-bundles/
+[params options]: #params-options
+[runner]: #runner
+[script options]: #script-options
+[script]: #script
+[SetOptions]: #optionssetter
+[with]: https://gohugo.io/functions/go-template/with/
\ No newline at end of file
diff --git a/content/en/functions/js/Build.md b/content/en/functions/js/Build.md
index 2a948416e0..0e5fd3c0a4 100644
--- a/content/en/functions/js/Build.md
+++ b/content/en/functions/js/Build.md
@@ -1,6 +1,7 @@
 ---
 title: js.Build
 description: Bundles, transpiles, tree shakes, and minifies JavaScript resources.
+weight: 30
 categories: []
 keywords: []
 action:
@@ -45,94 +46,10 @@ 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`) Params that can be imported as JSON in your JS files, e.g.
-
-```go-html-template
-{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}
-```
-And then in your JS file:
-
-```js
-import * as params from '@params';
-```
-
-Note that this is meant for small data sets, e.g. configuration settings. For larger data, please put/mount the files into `/assets` and import them directly.
-
-minify
-: (`bool`)Let `js.Build` handle the minification.
-
-inject
-: (`slice`) 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
-: (`map`) 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:
-
-```go-html-template
-{{ $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
-// js/shims/react.js
-module.exports = window.React;
-```
-
-```js
-// js/shims/react-dom.js
-module.exports = window.ReactDOM;
-```
-
-With the above, these imports should work in both scenarios:
-
-```js
-import * as React from 'react';
-import * as ReactDOM from 'react-dom/client';
-```
-
-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.
-
-```go-html-template
-{{ $defines := dict "process.env.NODE_ENV" `"development"` }}
-```
-
 format
 : (`string`) The output format. One of: `iife`, `cjs`, `esm`. Default is `iife`, a self-executing function, suitable for inclusion as a `<script>` tag.
 
-sourceMap
-: (`string`) Whether to generate `inline` or `external` source maps from esbuild. External source maps will be written to the target with the output file name + ".map". Input source maps can be read from js.Build and node modules and combined into the output source maps. By default, source maps are not created.
-
-JSX {{< new-in 0.124.0 >}}
-: (`string`) How to handle/transform JSX syntax. One of: `transform`, `preserve`, `automatic`. Default is `transform`. Notably, the `automatic` transform was introduced in React 17+ and will cause the necessary JSX helper functions to be imported automatically. See https://esbuild.github.io/api/#jsx
-
-JSXImportSource {{< new-in 0.124.0 >}}
-: (`string`) Which library to use to automatically import its JSX helper functions from. This only works if `JSX` is set to `automatic`. The specified library needs to be installed through npm and expose certain exports. See https://esbuild.github.io/api/#jsx-import-source
-
-The combination of `JSX` and `JSXImportSource` is helpful if you want to use a non-React JSX library like Preact, e.g.:
-
-```go-html-template
-{{ $js := resources.Get "js/main.jsx" | js.Build (dict "JSX" "automatic" "JSXImportSource" "preact") }}
-```
-
-With the above, you can use Preact components and JSX without having to manually import `h` and `Fragment` every time:
-
-```jsx
-import { render } from 'preact';
-
-const App = () => <>Hello world!</>;
-
-const container = document.getElementById('app');
-if (container) render(<App />, container);
-```
+{{% include "./_common/options.md" %}}
 
 ### Import JS code from /assets
 
diff --git a/content/en/functions/js/_common/_index.md b/content/en/functions/js/_common/_index.md
new file mode 100644
index 0000000000..4328d4d145
--- /dev/null
+++ b/content/en/functions/js/_common/_index.md
@@ -0,0 +1,13 @@
+---
+cascade:
+  _build:
+    list: never
+    publishResources: false
+    render: never
+---
+
+<!--
+Files within this headless branch bundle are Markdown snippets. Each file must contain front matter delimiters, though front matter fields are not required.
+
+Include the rendered content using the "include" shortcode. 
+-->
diff --git a/content/en/functions/js/_common/options.md b/content/en/functions/js/_common/options.md
new file mode 100644
index 0000000000..df594df129
--- /dev/null
+++ b/content/en/functions/js/_common/options.md
@@ -0,0 +1,99 @@
+---
+_comment: Do not remove front matter.
+---
+
+params
+: (`map` or `slice`) Params that can be imported as JSON in your JS files, e.g.
+
+```go-html-template
+{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}
+```
+And then in your JS file:
+
+```js
+import * as params from '@params';
+```
+
+Note that this is meant for small data sets, e.g. configuration settings. For larger data, please put/mount the files into `/assets` and import them directly.
+
+minify
+: (`bool`)Let `js.Build` handle the minification.
+
+loaders
+: (`map`) {{< new-in "0.140.0" >}}  Configuring a loader for a given file type lets you load that file type with an import statement or a require call. For example configuring the .png file extension to use the data URL loader means importing a .png file gives you a data URLcontaining the contents of that image. Loaders available are `none`, `base64`, `binary`, `copy`,  `css`,  `dataurl`, `default`, `empty`, `file`, `global-css`, `js`, `json`, `jsx`, `local-css`,  `text`, `ts`, `tsx`. See https://esbuild.github.io/api/#loader
+
+inject
+: (`slice`) 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
+: (`map`) 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:
+
+```go-html-template
+{{ $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
+// js/shims/react.js
+module.exports = window.React;
+```
+
+```js
+// js/shims/react-dom.js
+module.exports = window.ReactDOM;
+```
+
+With the above, these imports should work in both scenarios:
+
+```js
+import * as React from 'react';
+import * as ReactDOM from 'react-dom/client';
+```
+
+target
+: (`string`) The language target. One of: `es5`, `es2015`, `es2016`, `es2017`, `es2018`, `es2019`, `es2020` or `esnext`. Default is `esnext`.
+
+platform {{< new-in 0.140.0 >}}
+: (`string`) One of `browser`, `node`, `neutral`.  Default is `browser`. See https://esbuild.github.io/api/#platform
+
+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.
+
+```go-html-template
+{{ $defines := dict "process.env.NODE_ENV" `"development"` }}
+```
+
+sourceMap
+: (`string`) Whether to generate `inline`, `linked` or `external` source maps from esbuild. Linked and external source maps will be written to the target with the output file name + ".map". When `linked` a `sourceMappingURL` will also be written to the output file. By default, source maps are not created. Note that the `linked` option was added in Hugo 0.140.0.
+
+sourcesContent {{< new-in 0.140.0 >}}
+: (`bool`) Whether to include the content of the source files in the source map. By default, this is `true`.
+
+
+JSX {{< new-in 0.124.0 >}}
+: (`string`) How to handle/transform JSX syntax. One of: `transform`, `preserve`, `automatic`. Default is `transform`. Notably, the `automatic` transform was introduced in React 17+ and will cause the necessary JSX helper functions to be imported automatically. See https://esbuild.github.io/api/#jsx
+
+JSXImportSource {{< new-in 0.124.0 >}}
+: (`string`) Which library to use to automatically import its JSX helper functions from. This only works if `JSX` is set to `automatic`. The specified library needs to be installed through npm and expose certain exports. See https://esbuild.github.io/api/#jsx-import-source
+
+The combination of `JSX` and `JSXImportSource` is helpful if you want to use a non-React JSX library like Preact, e.g.:
+
+```go-html-template
+{{ $js := resources.Get "js/main.jsx" | js.Build (dict "JSX" "automatic" "JSXImportSource" "preact") }}
+```
+
+With the above, you can use Preact components and JSX without having to manually import `h` and `Fragment` every time:
+
+```jsx
+import { render } from 'preact';
+
+const App = () => <>Hello world!</>;
+
+const container = document.getElementById('app');
+if (container) render(<App />, container);
+```
\ No newline at end of file
diff --git a/content/en/hugo-pipes/babel.md b/content/en/hugo-pipes/babel.md
deleted file mode 100755
index 766ff8ae8b..0000000000
--- a/content/en/hugo-pipes/babel.md
+++ /dev/null
@@ -1,76 +0,0 @@
----
-title: Babel
-description: Hugo Pipes can process JS files with Babel.
-categories: [asset management]
-keywords: []
-menu:
-  docs:
-    parent: hugo-pipes
-    weight: 70
-weight: 70
-function:
-  aliases: [babel]
-  returnType: resource.Resource
-  signatures: ['js.Babel [OPTIONS] RESOURCE']
----
-
-## Usage
-
-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).
-
-{{% note %}}
-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.
-{{% /note %}}
-
-## 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.
-
-## Examples
-
-```go-html-template
-{{- $transpiled := resources.Get "scripts/main.js" | babel  -}}
-```
-
-Or with options:
-
-```go-html-template
-{{ $opts := dict "noComments" true }}
-{{- $transpiled := resources.Get "scripts/main.js" | babel $opts -}}
-```
diff --git a/content/en/hugo-pipes/js.md b/content/en/hugo-pipes/js.md
index ddde8313ae..e56ebf6975 100644
--- a/content/en/hugo-pipes/js.md
+++ b/content/en/hugo-pipes/js.md
@@ -1,7 +1,7 @@
 ---
-title: js.Build
+title: JavaScript
 linkTitle: JavaScript building
-description: Bundle, transpile, tree shake, and minify JavaScript resources.
+description: Bundle, transpile, tree shake, code split, and minify JavaScript resources.
 categories: [asset management]
 keywords: []
 menu:
@@ -9,181 +9,7 @@ menu:
     parent: hugo-pipes
     weight: 60
 weight: 60
-action:
-  aliases: []
-  returnType: resource.Resource
-  signatures: ['js.Build [OPTIONS] RESOURCE']
 ---
 
-## Usage
 
-Any JavaScript resource file can be transpiled and "tree shaken" using `js.Build` which takes for argument either a string for the file path 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`) Params that can be imported as JSON in your JS files, e.g.:
-
-```go-html-template
-{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}
-```
-And then in your JS file:
-
-```js
-import * as params from '@params';
-```
-
-Note that this is meant for small data sets, e.g. configuration settings. For larger data, please put/mount the files into `/assets` and import them directly.
-
-minify
-: (`bool`) Let `js.Build` handle the minification.
-
-inject
-: (`slice`) 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
-: (`map`) 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:
-
-```go-html-template
-{{ $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
-// js/shims/react.js
-module.exports = window.React;
-```
-
-```js
-// js/shims/react-dom.js
-module.exports = window.ReactDOM;
-```
-
-With the above, these imports should work in both scenarios:
-
-```js
-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.
-
-```go-html-template
-{{ $defines := dict "process.env.NODE_ENV" `"development"` }}
-```
-
-format
-: (`string`) The output format.
-  One of: `iife`, `cjs`, `esm`.
-  Default is `iife`, a self-executing function, suitable for inclusion as a `<script>` tag.
-
-sourceMap
-: (`string`) Whether to generate `inline` or `external` source maps from esbuild. External source maps will be written to the target with the output file name + ".map". Input source maps can be read from js.Build and node modules and combined into the output source maps. By default, source maps are not created.
-
-JSX {{< new-in 0.124.0 >}}
-: (`string`) How to handle/transform JSX syntax. One of: `transform`, `preserve`, `automatic`. Default is `transform`. Notably, the `automatic` transform was introduced in React 17+ and will cause the necessary JSX helper functions to be imported automatically. See https://esbuild.github.io/api/#jsx
-
-JSXImportSource {{< new-in 0.124.0 >}}
-: (`string`) Which library to use to automatically import its JSX helper functions from. This only works if `JSX` is set to `automatic`. The specified library needs to be installed through NPM and expose certain exports. See https://esbuild.github.io/api/#jsx-import-source
-
-The combination of `JSX` and `JSXImportSource` is helpful if you want to use a non-React JSX library like Preact, e.g.:
-
-```go-html-template
-{{ $js := resources.Get "js/main.jsx" | js.Build (dict "JSX" "automatic" "JSXImportSource" "preact") }}
-```
-
-With the above, you can use Preact components and JSX without having to manually import `h` and `Fragment` every time:
-
-```jsx
-import { render } from 'preact';
-
-const App = () => <>Hello world!</>;
-
-const container = document.getElementById('app');
-if (container) render(<App />, container);
-```
-
-### Import JS code from /assets
-
-`js.Build` has full support for the virtual union file system in [Hugo Modules](/hugo-modules/). You can see some simple examples in this [test project](https://github.com/gohugoio/hugoTestProjectJSModImports), but in short this means that you can do this:
-
-```js
-import { hello } from 'my/module';
-```
-
-And it will resolve to the top-most `index.{js,ts,tsx,jsx}` inside `assets/my/module` in the layered file system.
-
-```js
-import { hello3 } from 'my/module/hello3';
-```
-
-Will resolve to `hello3.{js,ts,tsx,jsx}` inside `assets/my/module`.
-
-Any imports starting with `.` is resolved relative to the current file:
-
-```js
-import { hello4 } from './lib';
-```
-
-For other files (e.g. `JSON`, `CSS`) you need to use the relative path including any extension, e.g:
-
-```js
-import * as data from 'my/module/data.json';
-```
-
-Any imports in a file outside `/assets` or that does not resolve to a component inside `/assets` will be resolved by [ESBuild](https://esbuild.github.io/) with the **project directory** as the resolve directory (used as the starting point when looking for `node_modules` etc.). Also see [hugo mod npm pack](/commands/hugo_mod_npm_pack/). If you have any imported npm dependencies in your project, you need to make sure to run `npm install` before you run `hugo`.
-
-Also note the new `params` option that can be passed from template to your JS files, e.g.:
-
-```go-html-template
-{{ $js := resources.Get "js/main.js" | js.Build (dict "params" (dict "api" "https://example.org/api")) }}
-```
-And then in your JS file:
-
-```js
-import * as params from '@params';
-```
-
-Hugo will, by default, generate a `assets/jsconfig.json` file that maps the imports. This is useful for navigation/intellisense help inside code editors, but if you don't need/want it, you can [turn it off](/getting-started/configuration/#configure-build).
-
-### Include dependencies In package.json / node_modules
-
-Any imports in a file outside `/assets` or that does not resolve to a component inside `/assets` will be resolved by [ESBuild](https://esbuild.github.io/) with the **project directory** as the resolve directory (used as the starting point when looking for `node_modules` etc.). Also see [hugo mod npm pack](/commands/hugo_mod_npm_pack/). If you have any imported npm dependencies in your project, you need to make sure to run `npm install` before you run `hugo`.
-
-The start directory for resolving npm packages (aka. packages that live inside a `node_modules` folder) is always the main project folder.
-
-{{% note %}}
-If you're developing a theme/component that is supposed to be imported and depends on dependencies inside `package.json`, we recommend reading about [hugo mod npm pack](/commands/hugo_mod_npm_pack/), a tool to consolidate all the npm dependencies in a project.
-{{% /note %}}
-
-### Examples
-
-```go-html-template
-{{ $built := resources.Get "js/index.js" | js.Build "main.js" }}
-```
-
-Or with options:
-
-```go-html-template
-{{ $externals := slice "react" "react-dom" }}
-{{ $defines := dict "process.env.NODE_ENV" `"development"` }}
-
-{{ $opts := dict "targetPath" "main.js" "externals" $externals "defines" $defines }}
-{{ $built := resources.Get "scripts/main.js" | js.Build $opts }}
-<script src="{{ $built.RelPermalink }}" defer></script>
-```
+See [JS functions](http://localhost:1313/functions/js/).
\ No newline at end of file
diff --git a/content/en/methods/page/Resources.md b/content/en/methods/page/Resources.md
index 54a61a2e45..0237ee352d 100644
--- a/content/en/methods/page/Resources.md
+++ b/content/en/methods/page/Resources.md
@@ -69,6 +69,20 @@ When working with global resources instead of page resources, use the [`resource
 
 When working with global resources instead of page resources, use the [`resources.Match`] function.
 
+###### Mount
+
+{{< new-in "0.140.0" >}}
+
+(`ResourceGetter`) Mounts the given resources from the two arguments base (`string`) to the given target path (`string`) and returns an object that implements [Get](#get). Note that leading slashes in target marks an absolute path. Relative target paths allows you to mount resources relative to another set, e.g. a [Page bundle](/content-management/page-bundles/):
+
+```go-html-template
+{{ $common := resources.Match "/js/headlessui/*.*" }}
+{{ $importContext := (slice $.Page ($common.Mount "/js/headlessui" ".")) }}
+```
+
+This method is currently only useful in [js.Batch](/functions/js/batch/#import-context).
+
+
 ## Pattern matching
 
 With the `GetMatch` and `Match` methods, Hugo determines a match using a case-insensitive [glob pattern].