1 files changed, 30 insertions, 14 deletions

diff --git a/lib/banzai/filter/table_of_contents_tag_filter.rb b/lib/banzai/filter/table_of_contents_tag_filter.rb
index 13d0a6a4cc7..4e80b543e2d 100644
--- a/lib/banzai/filter/table_of_contents_tag_filter.rb
+++ b/lib/banzai/filter/table_of_contents_tag_filter.rb
@@ -2,26 +2,31 @@
 
 module Banzai
   module Filter
-    # Using `[[_TOC_]]`, inserts a Table of Contents list.
-    # This syntax is based on the Gollum syntax. This way we have
-    # some consistency between with wiki and normal markdown.
-    # If there ever emerges a markdown standard, we can implement
-    # that here.
+    # Using `[[_TOC_]]` or `[TOC]` (both case insensitive), inserts a Table of Contents list.
     #
+    # `[[_TOC_]]` is based on the Gollum syntax. This way we have
+    # some consistency between with wiki and normal markdown.
     # The support for this has been removed from GollumTagsFilter
     #
+    # `[toc]` is a generally accepted form, used by Typora for example.
+    #
     # Based on Banzai::Filter::GollumTagsFilter
     class TableOfContentsTagFilter < HTML::Pipeline::Filter
-      TEXT_QUERY = %q(descendant-or-self::text()[ancestor::p and contains(., 'TOC')])
+      TEXT_QUERY = %q(descendant-or-self::text()[ancestor::p and contains(translate(., 'TOC', 'toc'), 'toc')])
 
       def call
         return doc if context[:no_header_anchors]
 
         doc.xpath(TEXT_QUERY).each do |node|
-          # A Gollum ToC tag is `[[_TOC_]]`, but due to MarkdownFilter running
-          # before this one, it will be converted into `[[<em>TOC</em>]]`, so it
-          # needs special-case handling
-          process_toc_tag(node) if toc_tag?(node)
+          if toc_tag?(node)
+            # Support [TOC] / [toc] tags, which don't have a wrapping <em>-tag
+            process_toc_tag(node)
+          elsif toc_tag_em?(node)
+            # Support Gollum like ToC tag (`[[_TOC_]]` / `[[_toc_]]`), which will be converted
+            # into `[[<em>TOC</em>]]` by the markdown filter, so it
+            # needs special-case handling
+            process_toc_tag_em(node)
+          end
         end
 
         doc
@@ -31,14 +36,25 @@ module Banzai
 
       # Replace an entire `[[<em>TOC</em>]]` node with the result generated by
       # TableOfContentsFilter
+      def process_toc_tag_em(node)
+        process_toc_tag(node.parent)
+      end
+
+      # Replace an entire `[TOC]` node with the result generated by
+      # TableOfContentsFilter
       def process_toc_tag(node)
-        node.parent.parent.replace(result[:toc].presence || '')
+        # we still need to go one step up to also replace the surrounding <p></p>
+        node.parent.replace(result[:toc].presence || '')
       end
 
-      def toc_tag?(node)
-        node.content == 'TOC' &&
+      def toc_tag_em?(node)
+        node.content.casecmp?('toc') &&
           node.parent.name == 'em' &&
-          node.parent.parent.text == '[[TOC]]'
+          node.parent.parent.text.casecmp?('[[toc]]')
+      end
+
+      def toc_tag?(node)
+        node.parent.text.casecmp?('[toc]')
       end
     end
   end