Add reference unfold pipeline used when moving issue

app/services/issues/move_service.rb

@@ -86,10 +86,13 @@ module Issues
                                     :snippets, :commits, :commit_ranges]
 
       cross_project_mentionables.each do |type|
-        references.public_send(type).each do |mentionable|
-          new_content.gsub!(mentionable.to_reference,
-                            mentionable.to_reference(@project_new))
-        end
+        referables = references.public_send(type)
+
+        context = { objects: referables, project: @project_new,
+                    pipeline: :reference_unfold }
+
+        new_content = Banzai.render_result(new_content, context)
+        new_content = new_content[:output].to_s
       end
 
       new_content

lib/banzai/filter/reference_unfold_filter.rb

+module Banzai
+  module Filter
+    ##
+    # Filter than unfolds local references.
+    #
+    # Replaces all local references with project cross reference version
+    # in all objects passed to this filter in context.
+    #
+    # Requires objects array with each element implementing `Referable`.
+    #
+    class ReferenceUnfoldFilter < ReferenceFilter
+      def initialize(*)
+        super
+
+        @objects = context[:objects]
+        @project = context[:project]
+
+        unless @objects.all? { |object| object.respond_to?(:to_reference) }
+          raise StandardError, "No `to_reference` method implemented in one of the objects !"
+        end
+
+        unless @project.kind_of?(Project)
+          raise StandardError, 'No valid project passed in context!'
+        end
+      end
+
+      def call
+        @objects.each do |object|
+          pattern = /#{Regexp.escape(object.to_reference)}/
+          replace_text_nodes_matching(pattern) do |content|
+            content.gsub(pattern, object.to_reference(@project))
+          end
+        end
+
+        doc
+      end
+
+      private
+
+      def validate
+        needs :project
+        needs :objects
+      end
+    end
+  end
+end

lib/banzai/pipeline/reference_unfold_pipeline.rb

+module Banzai
+  module Pipeline
+    class ReferenceUnfoldPipeline < BasePipeline
+      def self.filters
+        [Filter::ReferenceUnfoldFilter]
+      end
+    end
+  end
+end

spec/lib/banzai/pipeline/reference_unfold_pipeline_spec.rb

+require 'spec_helper'
+
+describe Banzai::Pipeline::ReferenceUnfoldPipeline do
+  let(:text) { 'some text' }
+  let(:project) { create(:project) }
+  let(:objects) { [] }
+
+  let(:result) do
+    described_class.to_html(text, project: project, objects: objects)
+  end
+
+  context 'invalid initializers' do
+    subject { -> { result } }
+
+    context 'project context is invalid' do
+      let(:project) { nil }
+      it { is_expected.to raise_error StandardError, /No valid project/ }
+    end
+
+    context 'objects context is invalid' do
+      let(:objects) { ['issue'] }
+      it { is_expected.to raise_error StandardError, /No `to_reference` method/ }
+    end
+  end
+
+  context 'multiple issues and merge requests referenced' do
+    subject { result }
+
+    let(:main_project) { create(:project) }
+
+    let(:issue_first) { create(:issue, project: main_project) }
+    let(:issue_second) { create(:issue, project: main_project) }
+    let(:merge_request) { create(:merge_request, source_project: main_project) }
+
+    let(:objects) { [issue_first, issue_second, merge_request] }
+
+    context 'plain text description' do
+      let(:text) { 'Description that references #1, #2 and !1' }
+
+      it { is_expected.to include issue_first.to_reference(project) }
+      it { is_expected.to include issue_second.to_reference(project) }
+      it { is_expected.to include merge_request.to_reference(project) }
+    end
+
+    context 'description with ignored elements' do
+      let(:text) do
+        <<-EOF
+          Hi. This references #1, but not `#2`
+          <pre>and not !1</pre>
+        EOF
+      end
+
+
+      it { is_expected.to include issue_first.to_reference(project) }
+      it { is_expected.to_not include issue_second.to_reference(project) }
+      it { is_expected.to_not include merge_request.to_reference(project) }
+    end
+  end
+end