From 3b895261fe71ebbaddac420e39b18027ce50ea41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Pedersen?=
 <bjorn.erik.pedersen@gmail.com>
Date: Mon, 5 Oct 2020 13:34:14 +0200
Subject: [PATCH] Make js.Build fully support modules

Fixes #7816
Fixes #7777
Fixes #7916
---
 content/en/getting-started/configuration.md |  4 ++
 content/en/hugo-pipes/js.md                 | 63 ++++++++++++++++++++-
 2 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/content/en/getting-started/configuration.md b/content/en/getting-started/configuration.md
index 392f71a66..fda7e2327 100644
--- a/content/en/getting-started/configuration.md
+++ b/content/en/getting-started/configuration.md
@@ -304,6 +304,7 @@ The `build` configuration section contains global build-related configuration op
 [build]
 useResourceCacheWhen="fallback"
 writeStats = false
+noJSConfigInAssets = false
 {{< /code-toggle >}}
 
 
@@ -313,6 +314,9 @@ useResourceCacheWhen
 writeStats {{< new-in "0.69.0" >}}
 : When enabled, a file named `hugo_stats.json` will be written to your project root with some aggregated data about the build, e.g. list of HTML entities published to be used to do [CSS pruning](/hugo-pipes/postprocess/#css-purging-with-postcss). If you're only using this for the production build, you should consider placing it below [config/production](/getting-started/configuration/#configuration-directory). It's also worth mentioning that, due to the nature of the partial server builds, new HTML entities will be added when you add or change them while the server is running, but the old values will not be removed until you restart the server or run a regular `hugo` build.
 
+noJSConfigInAssets {{< new-in "0.78.0" >}}
+: Turn off writing a `jsconfig.js` into your `/assets` folder with mapping of imports from running [js.Build](https://gohugo.io/hugo-pipes/js). This file is intended to help with intellisense/navigation inside code editors such as [VS Code](https://code.visualstudio.com/). Note that if you do not use `js.Build`, no file will be written.
+
 ## Configure Server
 
 {{< new-in "0.67.0" >}}
diff --git a/content/en/hugo-pipes/js.md b/content/en/hugo-pipes/js.md
index e7a0e9007..5e9c027d5 100644
--- a/content/en/hugo-pipes/js.md
+++ b/content/en/hugo-pipes/js.md
@@ -23,6 +23,20 @@ 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.:
+
+```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. config settings. For larger data, please put/mount the files into `/assets` and import them directly.
+
 minify [bool]
 : Let `js.Build` handle the minification.
 
@@ -50,7 +64,51 @@ defines [map]
 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 <script> tag. 
+  Default is `iife`, a self-executing function, suitable for inclusion as a <script> tag.
+
+
+### Import JS code from /assets
+
+{{< new-in "0.78.0" >}}
+
+Since Hugo `v0.78.0` `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 respolve 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';
+```
+
+Wil 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';
+```
+
+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.js` 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).
 
 ### Examples
 
@@ -69,7 +127,8 @@ Or with options:
 <script type="text/javascript" src="{{ $built.RelPermalink }}" defer></script>
 ```
 
-#### Shimming a JS library
+#### Shimming a JS library 
+
 It's a very common practice to load external libraries using CDN rather than importing all packages in a single JS file, making it bulky. To do the same with Hugo, you'll need to shim the libraries as follows. In this example, `algoliasearch` and `instantsearch.js` will be shimmed.
 
 Firstly, add the following to your project's `package.json`: