Enable CommonMark for files and wikis

app/helpers/markup_helper.rb

@@ -107,7 +107,6 @@ module MarkupHelper
 
   def markup(file_name, text, context = {})
     context[:project] ||= @project
-    context[:markdown_engine] ||= :redcarpet
     html = context.delete(:rendered) || markup_unsafe(file_name, text, context)
     prepare_for_rendering(html, context)
   end
@@ -121,8 +120,7 @@ module MarkupHelper
       project: @project,
       project_wiki: @project_wiki,
       page_slug: wiki_page.slug,
-      issuable_state_filter_enabled: true,
-      markdown_engine: :redcarpet
+      issuable_state_filter_enabled: true
     }
 
     html =

app/models/repository.rb

@@ -580,7 +580,7 @@ class Repository
   end
 
   def rendered_readme
-    MarkupHelper.markup_unsafe(readme.name, readme.data, project: project, markdown_engine: :redcarpet) if readme
+    MarkupHelper.markup_unsafe(readme.name, readme.data, project: project) if readme
   end
   cache_method :rendered_readme
 

app/views/projects/wikis/_form.html.haml

@@ -2,8 +2,7 @@
 - commit_message = commit_message % { page_title: @page.title }
 
 = form_for [@project.namespace.becomes(Namespace), @project, @page], method: @page.persisted? ? :put : :post,
-           html: { class: 'wiki-form common-note-form prepend-top-default js-quick-submit' },
-           data: { markdown_version: CacheMarkdownField::CACHE_REDCARPET_VERSION } do |f|
+           html: { class: 'wiki-form common-note-form prepend-top-default js-quick-submit' } do |f|
   = form_errors(@page)
 
   - if @page.persisted?

spec/helpers/markup_helper_spec.rb

@@ -207,7 +207,7 @@ describe MarkupHelper do
 
       expect(helper).to receive(:markdown_unsafe).with('wiki content',
         pipeline: :wiki, project: project, project_wiki: @wiki, page_slug: "nested/page",
-        issuable_state_filter_enabled: true, markdown_engine: :redcarpet)
+        issuable_state_filter_enabled: true)
 
       helper.render_wiki_content(@wiki)
     end
@@ -259,10 +259,12 @@ describe MarkupHelper do
       expect(helper.markup('foo.md', content, rendered: '<p>NOEL</p>')).to eq('<p>NOEL</p>')
     end
 
-    it 'defaults to Redcarpet' do
-      expect(helper).to receive(:markdown_unsafe).with(content, hash_including(markdown_engine: :redcarpet)).and_return('NOEL')
+    it 'defaults to CommonMark' do
+      expect(helper.markup('foo.md', 'x^2')).to include('x^2')
+    end
 
-      expect(helper.markup('foo.md', content)).to eq('NOEL')
+    it 'honors markdown_engine for RedCarpet' do
+      expect(helper.markup('foo.md', 'x^2', { markdown_engine: :redcarpet })).to include('x<sup>2</sup>')
     end
   end