Add merge request popover with details

- Show pipeline status, title, MR Status and project path
- Popover attached to gitlab flavored markdown everywhere, including:
  + MR/Issue Title
  + MR/Issue description
  + MR/Issue comments
  + Rendered markdown files

2 files changed, 17 insertions, 6 deletions

diff --git a/lib/banzai/filter/abstract_reference_filter.rb b/lib/banzai/filter/abstract_reference_filter.rb
index 4764f8e1e19..5f8aca104aa 100644
--- a/lib/banzai/filter/abstract_reference_filter.rb
+++ b/lib/banzai/filter/abstract_reference_filter.rb
@@ -181,9 +181,10 @@ module Banzai
             title = object_link_title(object, matches)
             klass = reference_class(object_sym)
 
-            data = data_attributes_for(link_content || match, parent, object,
-                                       link_content: !!link_content,
-                                       link_reference: link_reference)
+            data_attributes = data_attributes_for(link_content || match, parent, object,
+                                                  link_content: !!link_content,
+                                                  link_reference: link_reference)
+            data = data_attribute(data_attributes)
 
             url =
               if matches.names.include?("url") && matches[:url]
@@ -206,13 +207,13 @@ module Banzai
       def data_attributes_for(text, parent, object, link_content: false, link_reference: false)
         object_parent_type = parent.is_a?(Group) ? :group : :project
 
-        data_attribute(
+        {
           original:             text,
           link:                 link_content,
           link_reference:       link_reference,
           object_parent_type => parent.id,
           object_sym =>         object.id
-        )
+        }
       end
 
       def object_link_text_extras(object, matches)
diff --git a/lib/banzai/filter/merge_request_reference_filter.rb b/lib/banzai/filter/merge_request_reference_filter.rb
index 7098767b583..f05902078dc 100644
--- a/lib/banzai/filter/merge_request_reference_filter.rb
+++ b/lib/banzai/filter/merge_request_reference_filter.rb
@@ -20,7 +20,9 @@ module Banzai
       end
 
       def object_link_title(object, matches)
-        object_link_commit_title(object, matches) || super
+        # The method will return `nil` if object is not a commit
+        # allowing for properly handling the extended MR Tooltip
+        object_link_commit_title(object, matches)
       end
 
       def object_link_text_extras(object, matches)
@@ -53,6 +55,14 @@ module Banzai
           .includes(target_project: :namespace)
       end
 
+      def reference_class(object_sym, options = {})
+        super(object_sym, tooltip: false)
+      end
+
+      def data_attributes_for(text, parent, object, data = {})
+        super.merge(project_path: parent.full_path, iid: object.iid, mr_title: object.title)
+      end
+
       private
 
       def object_link_commit_title(object, matches)