feat: add support for type: 'local-css'

README.md

@@ -104,6 +104,27 @@ In all other cases `esbuild` won't process the CSS content which instead will be
 with any transformation function by keeping an internal cache of CSS chunks (virtual CSS files) 
 importing them in the module wrapping the contents
 
+#### `type: "local-css"`
+This mode uses esbuild's built-in CSS modules support (i.e. the [`local-css` loader](https://esbuild.github.io/content-types/#local-css)).
+Use this for lightweight Sass integration that then leverages esbuild's [built-in CSS processing features](https://esbuild.github.io/content-types/#css):
+
+```javascript
+await esbuild.build({
+  ...
+  plugins: [
+    sassPlugin({
+      filter: /\.module\.scss$/,
+      type: 'local-css'
+    }),
+    sassPlugin({
+      filter: /\.scss$/
+      type: 'css'
+    }),
+  ],
+  ...   
+})
+```
+
 #### `type: "style"`
 In this mode the stylesheet will be in the javascript bundle 
 and will be dynamically added to the page when the bundle is loaded.

src/index.ts

@@ -2,7 +2,7 @@ import {OnLoadResult} from 'esbuild'
 import {StringOptions} from 'sass'
 import {sassPlugin} from './plugin'
 
-export type Type = 'css' | 'style' | 'css-text' | 'lit-css' | ((cssText: string, nonce?: string) => string)
+export type Type = 'css' | 'local-css' | 'style' | 'css-text' | 'lit-css' | ((cssText: string, nonce?: string) => string)
 
 export type SassPluginOptions = StringOptions<'sync'|'async'> & {
 

src/plugin.ts

@@ -118,9 +118,9 @@ export function sassPlugin(options: SassPluginOptions = {}): Plugin {
             }
           }
 
-          return type === 'css' ? {
+          return type === 'css' || type === 'local-css' ? {
             contents: cssText,
-            loader: 'css',
+            loader: type,
             resolveDir,
             warnings,
             watchFiles

src/utils.ts

@@ -125,6 +125,7 @@ export function makeModule(contents: string, type: Type, nonce?: string):string
     case 'css-text':
       return cssTextModule(contents)
     case 'css':
+    case 'local-css':
       return contents
     default:
       return type(contents, nonce)

test/e2e.test.ts

@@ -333,6 +333,35 @@ describe('e2e tests', function () {
     `)
   })
 
+  it('local-css', async function () {
+    const options = useFixture('local-css')
+
+    await esbuild.build({
+      ...options,
+      entryPoints: ['./src/index.js'],
+      outdir: './out',
+      bundle: true,
+      format: 'esm',
+      plugins: [
+        sassPlugin({
+          type: 'local-css'
+        }),
+      ]
+    })
+
+    const bundle = readTextFile('./out/index.js')
+
+    expect(bundle).to.containIgnoreSpaces('class="${message} ${message2}"')
+
+    expect(bundle).to.containIgnoreSpaces(`
+      var message = "example_module_message";
+    `)
+
+    expect(bundle).to.containIgnoreSpaces(`
+      var message2 = "common_module_message";
+    `)
+  })
+
   it('open-iconic (dealing with relative paths & data urls)', async function () {
     const options = useFixture('open-iconic')
 

test/fixture/local-css/README.md

@@ -0,0 +1,31 @@
+### Example `build.js`
+```javascript
+const esbuild = require("esbuild");
+const {sassPlugin, postcssModules} = require("esbuild-sass-plugin");
+
+esbuild.build({
+    entryPoints: ["./src/index.js"],
+    outdir: "build/",
+    bundle: true,
+    format: "esm",
+    plugins: [
+        sassPlugin({
+            type: 'local-css'
+        }),
+    ]
+}).catch(() => process.exit(1));
+```
+
+### ...remember the dependencies in `package.json`
+```json
+  "dependencies": {
+    ...
+    "esbuild": "^0.12.20",
+    "esbuild-sass-plugin": "^1.5.0"
+    ...
+  }
+```
+
+**Note**:
+
+This project is slightly different from the example because it's part of the fixtures

test/fixture/local-css/build.js

@@ -0,0 +1,17 @@
+const esbuild = require('esbuild')
+const {sassPlugin} = require('../../../lib')
+const {cleanFixture, logSuccess, logFailure} = require('../utils')
+
+cleanFixture(__dirname)
+
+esbuild.build({
+  entryPoints: ['./src/index.js'],
+  outdir: './out',
+  bundle: true,
+  format: 'esm',
+  plugins: [
+    sassPlugin({
+      type: 'local-css'
+    }),
+  ]
+}).then(logSuccess, logFailure)

test/fixture/local-css/index.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Bootstrap Example</title>
+    <link href="out/index.css" rel="stylesheet">
+</head>
+<body>
+<script src="out/index.js" type="text/javascript"></script>
+</body>
+</html>

test/fixture/local-css/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "local-css-fixture",
+  "version": "1.0.0",
+  "license": "MIT",
+  "scripts": {
+    "build": "node ./build",
+    "serve": "node ../serve css-modules"
+  }
+}

test/fixture/local-css/src/common.module.scss

@@ -0,0 +1,3 @@
+.message {
+  font-family: Roboto, sans-serif;
+}

test/fixture/local-css/src/example.module.scss

@@ -0,0 +1,5 @@
+.message {
+  color: white;
+  background-color: red;
+  font-size: 24px;
+}

test/fixture/local-css/src/index.js

@@ -0,0 +1,6 @@
+import { message } from "./example.module.scss";
+import * as common from "./common.module.scss";
+
+document.body.insertAdjacentHTML("afterbegin", `
+    <div class="${message} ${common.message}">Hello World</div>
+`);