1 files changed, 88 insertions, 0 deletions
diff --git a/lib/banzai/filter/references/commit_reference_filter.rb b/lib/banzai/filter/references/commit_reference_filter.rb
new file mode 100644
index 00000000000..457921bd07d
--- /dev/null
+++ b/lib/banzai/filter/references/commit_reference_filter.rb
@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+module Banzai
+  module Filter
+    module References
+      # HTML filter that replaces commit references with links.
+      #
+      # This filter supports cross-project references.
+      class CommitReferenceFilter < AbstractReferenceFilter
+        self.reference_type = :commit
+
+        def self.object_class
+          Commit
+        end
+
+        def self.references_in(text, pattern = Commit.reference_pattern)
+          text.gsub(pattern) do |match|
+            yield match, $~[:commit], $~[:project], $~[:namespace], $~
+          end
+        end
+
+        def find_object(project, id)
+          return unless project.is_a?(Project) && project.valid_repo?
+
+          _, record = records_per_parent[project].detect { |k, _v| Gitlab::Git.shas_eql?(k, id) }
+
+          record
+        end
+
+        def referenced_merge_request_commit_shas
+          return [] unless noteable.is_a?(MergeRequest)
+
+          @referenced_merge_request_commit_shas ||= begin
+            referenced_shas = references_per_parent.values.reduce(:|).to_a
+            noteable.all_commit_shas.select do |sha|
+              referenced_shas.any? { |ref| Gitlab::Git.shas_eql?(sha, ref) }
+            end
+          end
+        end
+
+        # The default behaviour is `#to_i` - we just pass the hash through.
+        def self.parse_symbol(sha_hash, _match)
+          sha_hash
+        end
+
+        def url_for_object(commit, project)
+          h = Gitlab::Routing.url_helpers
+
+          if referenced_merge_request_commit_shas.include?(commit.id)
+            h.diffs_project_merge_request_url(project,
+                                              noteable,
+                                              commit_id: commit.id,
+                                              only_path: only_path?)
+          else
+            h.project_commit_url(project,
+                                 commit,
+                                 only_path: only_path?)
+          end
+        end
+
+        def object_link_text_extras(object, matches)
+          extras = super
+
+          path = matches[:path] if matches.names.include?("path")
+          if path == '/builds'
+            extras.unshift "builds"
+          end
+
+          extras
+        end
+
+        private
+
+        def parent_records(parent, ids)
+          parent.commits_by(oids: ids.to_a)
+        end
+
+        def noteable
+          context[:noteable]
+        end
+
+        def only_path?
+          context[:only_path]
+        end
+      end
+    end
+  end
+end