Refactor banzai to support referencing from group contextce-backport-3615

13 files changed, 163 insertions, 132 deletions

diff --git a/lib/banzai/cross_project_reference.rb b/lib/banzai/cross_project_reference.rb
index e2b57adf611..d8fb7705b2a 100644
--- a/lib/banzai/cross_project_reference.rb
+++ b/lib/banzai/cross_project_reference.rb
@@ -11,7 +11,7 @@ module Banzai
     # ref - String reference.
     #
     # Returns a Project, or nil if the reference can't be found
-    def project_from_ref(ref)
+    def parent_from_ref(ref)
       return context[:project] unless ref
 
       Project.find_by_full_path(ref)
diff --git a/lib/banzai/filter/abstract_reference_filter.rb b/lib/banzai/filter/abstract_reference_filter.rb
index 8975395aff1..e7e6a90b5fd 100644
--- a/lib/banzai/filter/abstract_reference_filter.rb
+++ b/lib/banzai/filter/abstract_reference_filter.rb
@@ -82,9 +82,9 @@ module Banzai
         end
       end
 
-      def project_from_ref_cached(ref)
-        cached_call(:banzai_project_refs, ref) do
-          project_from_ref(ref)
+      def from_ref_cached(ref)
+        cached_call("banzai_#{parent_type}_refs".to_sym, ref) do
+          parent_from_ref(ref)
         end
       end
 
@@ -153,15 +153,20 @@ module Banzai
       # have `gfm` and `gfm-OBJECT_NAME` class names attached for styling.
       def object_link_filter(text, pattern, link_content: nil, link_reference: false)
         references_in(text, pattern) do |match, id, project_ref, namespace_ref, matches|
-          project_path = full_project_path(namespace_ref, project_ref)
-          project = project_from_ref_cached(project_path)
+          parent_path = if parent_type == :group
+                          full_group_path(namespace_ref)
+                        else
+                          full_project_path(namespace_ref, project_ref)
+                        end
 
-          if project
+          parent = from_ref_cached(parent_path)
+
+          if parent
             object =
               if link_reference
-                find_object_from_link_cached(project, id)
+                find_object_from_link_cached(parent, id)
               else
-                find_object_cached(project, id)
+                find_object_cached(parent, id)
               end
           end
 
@@ -169,13 +174,13 @@ module Banzai
             title = object_link_title(object)
             klass = reference_class(object_sym)
 
-            data = data_attributes_for(link_content || match, project, object, link: !!link_content)
+            data = data_attributes_for(link_content || match, parent, object, link: !!link_content)
 
             url =
               if matches.names.include?("url") && matches[:url]
                 matches[:url]
               else
-                url_for_object_cached(object, project)
+                url_for_object_cached(object, parent)
               end
 
             content = link_content || object_link_text(object, matches)
@@ -224,17 +229,24 @@ module Banzai
 
       # Returns a Hash containing all object references (e.g. issue IDs) per the
       # project they belong to.
-      def references_per_project
-        @references_per_project ||= begin
+      def references_per_parent
+        @references_per ||= {}
+
+        @references_per[parent_type] ||= begin
           refs = Hash.new { |hash, key| hash[key] = Set.new }
 
           regex = Regexp.union(object_class.reference_pattern, object_class.link_reference_pattern)
 
           nodes.each do |node|
             node.to_html.scan(regex) do
-              project_path = full_project_path($~[:namespace], $~[:project])
+              path = if parent_type == :project
+                       full_project_path($~[:namespace], $~[:project])
+                     else
+                       full_group_path($~[:group])
+                     end
+
               symbol = $~[object_sym]
-              refs[project_path] << symbol if object_class.reference_valid?(symbol)
+              refs[path] << symbol if object_class.reference_valid?(symbol)
             end
           end
 
@@ -244,35 +256,41 @@ module Banzai
 
       # Returns a Hash containing referenced projects grouped per their full
       # path.
-      def projects_per_reference
-        @projects_per_reference ||= begin
+      def parent_per_reference
+        @per_reference ||= {}
+
+        @per_reference[parent_type] ||= begin
           refs = Set.new
 
-          references_per_project.each do |project_ref, _|
-            refs << project_ref
+          references_per_parent.each do |ref, _|
+            refs << ref
           end
 
-          find_projects_for_paths(refs.to_a).index_by(&:full_path)
+          find_for_paths(refs.to_a).index_by(&:full_path)
         end
       end
 
-      def projects_relation_for_paths(paths)
-        Project.where_full_path_in(paths).includes(:namespace)
+      def relation_for_paths(paths)
+        klass = parent_type.to_s.camelize.constantize
+        result = klass.where_full_path_in(paths)
+        return result if parent_type == :group
+
+        result.includes(:namespace) if parent_type == :project
       end
 
       # Returns projects for the given paths.
-      def find_projects_for_paths(paths)
+      def find_for_paths(paths)
         if RequestStore.active?
-          cache = project_refs_cache
+          cache = refs_cache
           to_query = paths - cache.keys
 
           unless to_query.empty?
-            projects = projects_relation_for_paths(to_query)
+            records = relation_for_paths(to_query)
 
             found = []
-            projects.each do |project|
-              ref = project.full_path
-              get_or_set_cache(cache, ref) { project }
+            records.each do |record|
+              ref = record.full_path
+              get_or_set_cache(cache, ref) { record }
               found << ref
             end
 
@@ -284,33 +302,37 @@ module Banzai
 
           cache.slice(*paths).values.compact
         else
-          projects_relation_for_paths(paths)
+          relation_for_paths(paths)
         end
       end
 
-      def current_project_path
-        return unless project
-
-        @current_project_path ||= project.full_path
+      def current_parent_path
+        @current_parent_path ||= parent&.full_path
       end
 
       def current_project_namespace_path
-        return unless project
-
-        @current_project_namespace_path ||= project.namespace.full_path
+        @current_project_namespace_path ||= project&.namespace&.full_path
       end
 
       private
 
       def full_project_path(namespace, project_ref)
-        return current_project_path unless project_ref
+        return current_parent_path unless project_ref
 
         namespace_ref = namespace || current_project_namespace_path
         "#{namespace_ref}/#{project_ref}"
       end
 
-      def project_refs_cache
-        RequestStore[:banzai_project_refs] ||= {}
+      def refs_cache
+        RequestStore["banzai_#{parent_type}_refs".to_sym] ||= {}
+      end
+
+      def parent_type
+        :project
+      end
+
+      def parent
+        parent_type == :project ? project : group
       end
     end
   end
diff --git a/lib/banzai/filter/epic_reference_filter.rb b/lib/banzai/filter/epic_reference_filter.rb
new file mode 100644
index 00000000000..265924abe24
--- /dev/null
+++ b/lib/banzai/filter/epic_reference_filter.rb
@@ -0,0 +1,12 @@
+module Banzai
+  module Filter
+    # The actual filter is implemented in the EE mixin
+    class EpicReferenceFilter < IssuableReferenceFilter
+      self.reference_type = :epic
+
+      def self.object_class
+        Epic
+      end
+    end
+  end
+end
diff --git a/lib/banzai/filter/issuable_reference_filter.rb b/lib/banzai/filter/issuable_reference_filter.rb
new file mode 100644
index 00000000000..7addf09be73
--- /dev/null
+++ b/lib/banzai/filter/issuable_reference_filter.rb
@@ -0,0 +1,31 @@
+module Banzai
+  module Filter
+    class IssuableReferenceFilter < AbstractReferenceFilter
+      def records_per_parent
+        @records_per_project ||= {}
+
+        @records_per_project[object_class.to_s.underscore] ||= begin
+          hash = Hash.new { |h, k| h[k] = {} }
+
+          parent_per_reference.each do |path, parent|
+            record_ids = references_per_parent[path]
+
+            parent_records(parent, record_ids).each do |record|
+              hash[parent][record.iid.to_i] = record
+            end
+          end
+
+          hash
+        end
+      end
+
+      def find_object(parent, iid)
+        records_per_parent[parent][iid]
+      end
+
+      def parent_from_ref(ref)
+        parent_per_reference[ref || current_parent_path]
+      end
+    end
+  end
+end
diff --git a/lib/banzai/filter/issue_reference_filter.rb b/lib/banzai/filter/issue_reference_filter.rb
index ce1ab977d3b..6877cae8c55 100644
--- a/lib/banzai/filter/issue_reference_filter.rb
+++ b/lib/banzai/filter/issue_reference_filter.rb
@@ -8,46 +8,24 @@ module Banzai
     # When external issues tracker like Jira is activated we should not
     # use issue reference pattern, but we should still be able
     # to reference issues from other GitLab projects.
-    class IssueReferenceFilter < AbstractReferenceFilter
+    class IssueReferenceFilter < IssuableReferenceFilter
       self.reference_type = :issue
 
       def self.object_class
         Issue
       end
 
-      def find_object(project, iid)
-        issues_per_project[project][iid]
-      end
-
       def url_for_object(issue, project)
         IssuesHelper.url_for_issue(issue.iid, project, only_path: context[:only_path], internal: true)
       end
 
-      def project_from_ref(ref)
-        projects_per_reference[ref || current_project_path]
-      end
-
-      # Returns a Hash containing the issues per Project instance.
-      def issues_per_project
-        @issues_per_project ||= begin
-          hash = Hash.new { |h, k| h[k] = {} }
-
-          projects_per_reference.each do |path, project|
-            issue_ids = references_per_project[path]
-            issues = project.issues.where(iid: issue_ids.to_a)
-
-            issues.each do |issue|
-              hash[project][issue.iid.to_i] = issue
-            end
-          end
-
-          hash
-        end
-      end
-
       def projects_relation_for_paths(paths)
         super(paths).includes(:gitlab_issue_tracker_service)
       end
+
+      def parent_records(parent, ids)
+        parent.issues.where(iid: ids.to_a)
+      end
     end
   end
 end
diff --git a/lib/banzai/filter/label_reference_filter.rb b/lib/banzai/filter/label_reference_filter.rb
index 5364984c9d3..d5360ad8f68 100644
--- a/lib/banzai/filter/label_reference_filter.rb
+++ b/lib/banzai/filter/label_reference_filter.rb
@@ -33,7 +33,7 @@ module Banzai
       end
 
       def find_label(project_ref, label_id, label_name)
-        project = project_from_ref(project_ref)
+        project = parent_from_ref(project_ref)
         return unless project
 
         label_params = label_params(label_id, label_name)
@@ -66,7 +66,7 @@ module Banzai
 
       def object_link_text(object, matches)
         project_path     = full_project_path(matches[:namespace], matches[:project])
-        project_from_ref = project_from_ref_cached(project_path)
+        project_from_ref = from_ref_cached(project_path)
         reference        = project_from_ref.to_human_reference(project)
         label_suffix     = " <i>in #{reference}</i>" if reference.present?
 
diff --git a/lib/banzai/filter/merge_request_reference_filter.rb b/lib/banzai/filter/merge_request_reference_filter.rb
index 0eab865ac04..b3cfa97d0e0 100644
--- a/lib/banzai/filter/merge_request_reference_filter.rb
+++ b/lib/banzai/filter/merge_request_reference_filter.rb
@@ -4,48 +4,19 @@ module Banzai
     # to merge requests that do not exist are ignored.
     #
     # This filter supports cross-project references.
-    class MergeRequestReferenceFilter < AbstractReferenceFilter
+    class MergeRequestReferenceFilter < IssuableReferenceFilter
       self.reference_type = :merge_request
 
       def self.object_class
         MergeRequest
       end
 
-      def find_object(project, iid)
-        merge_requests_per_project[project][iid]
-      end
-
       def url_for_object(mr, project)
         h = Gitlab::Routing.url_helpers
         h.project_merge_request_url(project, mr,
                                             only_path: context[:only_path])
       end
 
-      def project_from_ref(ref)
-        projects_per_reference[ref || current_project_path]
-      end
-
-      # Returns a Hash containing the merge_requests per Project instance.
-      def merge_requests_per_project
-        @merge_requests_per_project ||= begin
-          hash = Hash.new { |h, k| h[k] = {} }
-
-          projects_per_reference.each do |path, project|
-            merge_request_ids = references_per_project[path]
-
-            merge_requests = project.merge_requests
-              .where(iid: merge_request_ids.to_a)
-              .includes(target_project: :namespace)
-
-            merge_requests.each do |merge_request|
-              hash[project][merge_request.iid.to_i] = merge_request
-            end
-          end
-
-          hash
-        end
-      end
-
       def object_link_text_extras(object, matches)
         extras = super
 
@@ -61,6 +32,12 @@ module Banzai
 
         extras
       end
+
+      def parent_records(parent, ids)
+        parent.merge_requests
+          .where(iid: ids.to_a)
+          .includes(target_project: :namespace)
+      end
     end
   end
 end
diff --git a/lib/banzai/filter/milestone_reference_filter.rb b/lib/banzai/filter/milestone_reference_filter.rb
index bb5da310e09..2a6b0964ac5 100644
--- a/lib/banzai/filter/milestone_reference_filter.rb
+++ b/lib/banzai/filter/milestone_reference_filter.rb
@@ -38,7 +38,7 @@ module Banzai
 
       def find_milestone(project_ref, namespace_ref, milestone_id, milestone_name)
         project_path = full_project_path(namespace_ref, project_ref)
-        project = project_from_ref(project_path)
+        project = parent_from_ref(project_path)
 
         return unless project
 
diff --git a/lib/banzai/issuable_extractor.rb b/lib/banzai/issuable_extractor.rb
index cbabf9156de..49603d0b363 100644
--- a/lib/banzai/issuable_extractor.rb
+++ b/lib/banzai/issuable_extractor.rb
@@ -28,8 +28,8 @@ module Banzai
       issue_parser = Banzai::ReferenceParser::IssueParser.new(project, user)
       merge_request_parser = Banzai::ReferenceParser::MergeRequestParser.new(project, user)
 
-      issuables_for_nodes = issue_parser.issues_for_nodes(nodes).merge(
-        merge_request_parser.merge_requests_for_nodes(nodes)
+      issuables_for_nodes = issue_parser.records_for_nodes(nodes).merge(
+        merge_request_parser.records_for_nodes(nodes)
       )
 
       # The project for the issue/MR might be pending for deletion!
diff --git a/lib/banzai/reference_parser/epic_parser.rb b/lib/banzai/reference_parser/epic_parser.rb
new file mode 100644
index 00000000000..08b8a4c9a0f
--- /dev/null
+++ b/lib/banzai/reference_parser/epic_parser.rb
@@ -0,0 +1,12 @@
+module Banzai
+  module ReferenceParser
+    # The actual parser is implemented in the EE mixin
+    class EpicParser < IssuableParser
+      self.reference_type = :epic
+
+      def records_for_nodes(_nodes)
+        {}
+      end
+    end
+  end
+end
diff --git a/lib/banzai/reference_parser/issuable_parser.rb b/lib/banzai/reference_parser/issuable_parser.rb
new file mode 100644
index 00000000000..3953867eb83
--- /dev/null
+++ b/lib/banzai/reference_parser/issuable_parser.rb
@@ -0,0 +1,25 @@
+module Banzai
+  module ReferenceParser
+    class IssuableParser < BaseParser
+      def nodes_visible_to_user(user, nodes)
+        records = records_for_nodes(nodes)
+
+        nodes.select do |node|
+          issuable = records[node]
+
+          issuable && can_read_reference?(user, issuable)
+        end
+      end
+
+      def referenced_by(nodes)
+        records = records_for_nodes(nodes)
+
+        nodes.map { |node| records[node] }.compact.uniq
+      end
+
+      def can_read_reference?(user, issuable)
+        can?(user, "read_#{issuable.class.to_s.underscore}".to_sym, issuable)
+      end
+    end
+  end
+end
diff --git a/lib/banzai/reference_parser/issue_parser.rb b/lib/banzai/reference_parser/issue_parser.rb
index e0a8ca653cb..38d4e3f3e44 100644
--- a/lib/banzai/reference_parser/issue_parser.rb
+++ b/lib/banzai/reference_parser/issue_parser.rb
@@ -1,10 +1,10 @@
 module Banzai
   module ReferenceParser
-    class IssueParser < BaseParser
+    class IssueParser < IssuableParser
       self.reference_type = :issue
 
       def nodes_visible_to_user(user, nodes)
-        issues = issues_for_nodes(nodes)
+        issues = records_for_nodes(nodes)
 
         readable_issues = Ability
           .issues_readable_by_user(issues.values, user).to_set
@@ -14,13 +14,7 @@ module Banzai
         end
       end
 
-      def referenced_by(nodes)
-        issues = issues_for_nodes(nodes)
-
-        nodes.map { |node| issues[node] }.compact.uniq
-      end
-
-      def issues_for_nodes(nodes)
+      def records_for_nodes(nodes)
         @issues_for_nodes ||= grouped_objects_for_nodes(
           nodes,
           Issue.all.includes(
diff --git a/lib/banzai/reference_parser/merge_request_parser.rb b/lib/banzai/reference_parser/merge_request_parser.rb
index 75cbc7fdac4..a370ff5b5b3 100644
--- a/lib/banzai/reference_parser/merge_request_parser.rb
+++ b/lib/banzai/reference_parser/merge_request_parser.rb
@@ -1,25 +1,9 @@
 module Banzai
   module ReferenceParser
-    class MergeRequestParser < BaseParser
+    class MergeRequestParser < IssuableParser
       self.reference_type = :merge_request
 
-      def nodes_visible_to_user(user, nodes)
-        merge_requests = merge_requests_for_nodes(nodes)
-
-        nodes.select do |node|
-          merge_request = merge_requests[node]
-
-          merge_request && can?(user, :read_merge_request, merge_request.project)
-        end
-      end
-
-      def referenced_by(nodes)
-        merge_requests = merge_requests_for_nodes(nodes)
-
-        nodes.map { |node| merge_requests[node] }.compact.uniq
-      end
-
-      def merge_requests_for_nodes(nodes)
+      def records_for_nodes(nodes)
         @merge_requests_for_nodes ||= grouped_objects_for_nodes(
           nodes,
           MergeRequest.includes(
@@ -40,10 +24,6 @@ module Banzai
           self.class.data_attribute
         )
       end
-
-      def can_read_reference?(user, ref_project, node)
-        can?(user, :read_merge_request, ref_project)
-      end
     end
   end
 end