Merge branch '14193-support-toc-markdown' into 'master'

Add support for [TOC] as alias for [[_TOC_]] in Markdown

See merge request gitlab-org/gitlab!66329

doc/user/markdown.md

@@ -410,7 +410,7 @@ To create a task list, follow the format of an ordered or unordered list:
 A table of contents is an unordered list that links to subheadings in the document.
 
 To add a table of contents to a Markdown file, wiki page, issue request, or merge request
-description, add the `[[_TOC_]]` tag on its own line.
+description, add either the `[[_TOC_]]` or `[TOC]` tag on its own line.
 
 NOTE:
 You can add a table of contents to issues and merge requests, but you can't add one

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
+          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(node) if toc_tag?(node)
+            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

spec/lib/banzai/filter/table_of_contents_tag_filter_spec.rb

@@ -6,9 +6,8 @@ RSpec.describe Banzai::Filter::TableOfContentsTagFilter do
   include FilterSpecHelper
 
   context 'table of contents' do
-    let(:html) { '<p>[[<em>TOC</em>]]</p>' }
-
-    it 'replaces [[<em>TOC</em>]] with ToC result' do
+    shared_examples 'table of contents tag' do
+      it 'replaces toc tag with ToC result' do
         doc = filter(html, {}, { toc: "FOO" })
 
         expect(doc.to_html).to eq("FOO")
@@ -20,4 +19,29 @@ RSpec.describe Banzai::Filter::TableOfContentsTagFilter do
         expect(doc.to_html).to eq ''
       end
     end
+
+    context '[[_TOC_]] as tag' do
+      it_behaves_like 'table of contents tag' do
+        let(:html) { '<p>[[<em>TOC</em>]]</p>' }
+      end
+    end
+
+    context '[[_toc_]] as tag' do
+      it_behaves_like 'table of contents tag' do
+        let(:html) { '<p>[[<em>toc</em>]]</p>' }
+      end
+    end
+
+    context '[TOC] as tag' do
+      it_behaves_like 'table of contents tag' do
+        let(:html) { '<p>[TOC]</p>' }
+      end
+    end
+
+    context '[toc] as tag' do
+      it_behaves_like 'table of contents tag' do
+        let(:html) { '<p>[toc]</p>' }
+      end
+    end
+  end
 end

spec/lib/banzai/pipeline/full_pipeline_spec.rb

@@ -102,9 +102,11 @@ RSpec.describe Banzai::Pipeline::FullPipeline do
 
   describe 'table of contents' do
     let(:project) { create(:project, :public) }
+
+    shared_examples 'table of contents tag' do |tag, tag_html|
       let(:markdown) do
         <<-MARKDOWN.strip_heredoc
-          [[_TOC_]]
+          #{tag}
 
           # Header
         MARKDOWN
@@ -112,7 +114,7 @@ RSpec.describe Banzai::Pipeline::FullPipeline do
 
       let(:invalid_markdown) do
         <<-MARKDOWN.strip_heredoc
-          test [[_TOC_]]
+          test #{tag}
 
           # Header
         MARKDOWN
@@ -128,7 +130,17 @@ RSpec.describe Banzai::Pipeline::FullPipeline do
       it 'does not insert a table of contents' do
         output = described_class.to_html(invalid_markdown, project: project)
 
-      expect(output).to include("test [[<em>TOC</em>]]")
+        expect(output).to include("test #{tag_html}")
+      end
+    end
+
+    context 'with [[_TOC_]] as tag' do
+      it_behaves_like 'table of contents tag', '[[_TOC_]]', '[[<em>TOC</em>]]'
+    end
+
+    context 'with [toc] as tag' do
+      it_behaves_like 'table of contents tag', '[toc]', '[toc]'
+      it_behaves_like 'table of contents tag', '[TOC]', '[TOC]'
     end
   end
 

spec/lib/banzai/pipeline/wiki_pipeline_spec.rb

@@ -27,7 +27,7 @@ RSpec.describe Banzai::Pipeline::WikiPipeline do
       end
     end
 
-    it 'is case-sensitive' do
+    it 'is not case-sensitive' do
       markdown = <<-MD.strip_heredoc
           [[_toc_]]
 
@@ -36,9 +36,22 @@ RSpec.describe Banzai::Pipeline::WikiPipeline do
           Foo
       MD
 
-      output = described_class.to_html(markdown, project: project, wiki: wiki)
+      result = described_class.call(markdown, project: project, wiki: wiki)
+
+      expect(result[:output].to_html).to include(result[:toc])
+    end
+
+    it 'works with alternative [toc] tag' do
+      markdown = <<-MD.strip_heredoc
+          [toc]
 
-      expect(output).to include('[[<em>toc</em>]]')
+          # Header 1
+
+          Foo
+      MD
+
+      result = described_class.call(markdown, project: project, wiki: wiki)
+      expect(result[:output].to_html).to include(result[:toc])
     end
 
     it 'handles an empty pipeline result' do