[devdocsgjs/main: 183/239] Cleanup tailwind classes when generating markup

[Andy Holmes <andyholmes src gnome org>]

commit 7efdd2dbf0feb8150e9e7610cfa82317da849d29
Author: IgnusG <6438760+IgnusG users noreply github com>
Date:   Mon Feb 21 21:40:08 2022 +0100

    Cleanup tailwind classes when generating markup

 lib/docs/filters/tailwindcss/clean_html.rb | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)
---
diff --git a/lib/docs/filters/tailwindcss/clean_html.rb b/lib/docs/filters/tailwindcss/clean_html.rb
index 4842a585..7eecf562 100644
--- a/lib/docs/filters/tailwindcss/clean_html.rb
+++ b/lib/docs/filters/tailwindcss/clean_html.rb
@@ -1,3 +1,26 @@
+# Removes all classes not allowlisted in the below semantic_classes array - such as tailwinds utility classes
+def cleanup_tailwind_classes(node)
+  class_name = node.attr("class")
+
+  if class_name == nil
+    return node.children.each { |child| cleanup_tailwind_classes(child) }
+  end
+
+  semantic_classes = ["code", "color-swatch", "color-swatch-container", "color-tone-information", 
"color-swatch-group", "color", "colors", "long-quick-reference"]
+
+  classes = class_name.split.select do |klas|
+    semantic_classes.include? klas
+  end
+
+  if classes.length === 0
+    node.delete("class")
+  else
+    node.set_attribute("class", classes.join(" "))
+  end
+
+  node.children.each { |child| cleanup_tailwind_classes(child) }
+end
+
 module Docs
   class Tailwindcss
     class CleanHtmlFilter < Filter
@@ -52,11 +75,12 @@ module Docs
           node.parent.parent['class'] = node.parent.parent['class'].gsub(/bg-.*?\b/, ' ');
         end
 
+        @doc.traverse { |node| cleanup_tailwind_classes(node) }
+
         #remove weird <hr> 
(https://github.com/damms005/devdocs/commit/8c9fbd859b71a2525b94a35ea994393ce2b6fedb#commitcomment-50091018)
         css('hr').remove
 
         doc
-
       end
     end
   end