From 81ed7444e3023087eaabfc08dd8dc525bcb60cd8 Mon Sep 17 00:00:00 2001
From: Jelle De Loecker <jelle@elevenways.be>
Date: Sun, 3 Mar 2024 23:09:52 +0100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Add=20`postcss-prune-var`=20depende?=
 =?UTF-8?q?ncy=20to=20remove=20unused=20variables=20from=20CSS=20files?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 CHANGELOG.md           |  1 +
 lib/core/middleware.js | 14 +++++++++++++-
 package.json           |  1 +
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index afe53c7..26e7acc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 * Add the abstract `Meta` field class: these should be used for fields that are not directly stored in the database
 * Add association aliases as a meta field to model schemas
 * Add `should_add_exports()` SCSS function
+* Add `postcss-prune-var` dependency to remove unused variables from CSS files
 
 ## 1.4.0-alpha.3 (2024-02-25)
 
diff --git a/lib/core/middleware.js b/lib/core/middleware.js
index 4e64759..df53baa 100644
--- a/lib/core/middleware.js
+++ b/lib/core/middleware.js
@@ -16,6 +16,7 @@ let publicDirs = alchemy.shared('public.directories', new Deck()),
     regenerator_runtime,
     sass_functions,
     babel_polyfill,
+    postcss_prune,
     babel_preset,
     babel_async,
     autoprefixer,
@@ -93,6 +94,7 @@ if (alchemy.settings.frontend.stylesheet.enable_scss) {
 if (alchemy.settings.frontend.stylesheet.enable_post !== false) {
 	postcss = alchemy.use('postcss');
 	autoprefixer = alchemy.use('autoprefixer');
+	postcss_prune = alchemy.use('postcss-prune-var')();
 }
 
 if (alchemy.settings.frontend.javascript.enable_babel) {
@@ -1009,7 +1011,16 @@ Alchemy.setMethod(function findAssetPath(assetFile, directories, callback) {
  * @param    {Function}   callback
  */
 function doPostCss(css, options, callback) {
-	postcss([autoprefixer]).process(css, {from: undefined}).then(function gotCssResult(result) {
+
+	let postcss_config = [
+		autoprefixer
+	];
+
+	if (options.prune !== false) {
+		postcss_config.push(postcss_prune);
+	}
+
+	postcss(postcss_config).process(css, {from: undefined}).then(function gotCssResult(result) {
 
 		if (options?.post_css_only) {
 			return callback(null, result);
@@ -1486,6 +1497,7 @@ Alchemy.setMethod(async function extractCSSExports(css_path) {
 	let result = await findStylesheet(css_path, {
 		post_css_only: true,
 		add_exports: true,
+		prune: false,
 		compile: true
 	});
 
diff --git a/package.json b/package.json
index b70a54c..17d691f 100644
--- a/package.json
+++ b/package.json
@@ -31,6 +31,7 @@
 		"mongodb"          : "~6.1.0",
 		"ncp"              : "~2.0.0",
 		"postcss"          : "~8.4.31",
+		"postcss-prune-var": "~1.1.2",
 		"protoblast"       : "~0.9.1",
 		"semver"           : "~7.5.4",
 		"socket.io"        : "~4.7.2",