1 files changed, 32 insertions, 0 deletions
diff --git a/app/services/markdown_content_rewriter_service.rb b/app/services/markdown_content_rewriter_service.rb
new file mode 100644
index 00000000000..bc6fd592eaa
--- /dev/null
+++ b/app/services/markdown_content_rewriter_service.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+# This service passes Markdown content through our GFM rewriter classes
+# which rewrite references to GitLab objects and uploads within the content
+# based on their visibility by the `target_parent`.
+class MarkdownContentRewriterService
+  REWRITERS = [Gitlab::Gfm::ReferenceRewriter, Gitlab::Gfm::UploadsRewriter].freeze
+
+  def initialize(current_user, content, source_parent, target_parent)
+    # See https://gitlab.com/gitlab-org/gitlab/-/merge_requests/39654#note_399095117
+    raise ArgumentError, 'The rewriter classes require that `source_parent` is a `Project`' \
+      unless source_parent.is_a?(Project)
+
+    @current_user = current_user
+    @content = content.presence
+    @source_parent = source_parent
+    @target_parent = target_parent
+  end
+
+  def execute
+    return unless content
+
+    REWRITERS.inject(content) do |text, klass|
+      rewriter = klass.new(text, source_parent, current_user)
+      rewriter.rewrite(target_parent)
+    end
+  end
+
+  private
+
+  attr_reader :current_user, :content, :source_parent, :target_parent
+end