Move Issue#{referenced,closed_by}_merge_requests to service

These methods don't really need to be on the Issue model. Issue#related_branches
can also be moved to a service, but we can do that in a separate commit.

This commit does not change any behaviour; it just moves code around, renames
the service, and refactors the specs.

2 files changed, 72 insertions, 35 deletions

diff --git a/spec/services/issues/fetch_referenced_merge_requests_service_spec.rb b/spec/services/issues/fetch_referenced_merge_requests_service_spec.rb
deleted file mode 100644
index 4e58179f45f..00000000000
--- a/spec/services/issues/fetch_referenced_merge_requests_service_spec.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-require 'spec_helper.rb'
-
-describe Issues::FetchReferencedMergeRequestsService do
-  let(:project) { create(:project) }
-  let(:issue) { create(:issue, project: project) }
-  let(:other_project) { create(:project) }
-
-  let(:mr) { create(:merge_request, source_project: project, target_project: project, id: 2)}
-  let(:other_mr) { create(:merge_request, source_project: other_project, target_project: other_project, id: 1)}
-
-  let(:user) { create(:user) }
-  let(:service) { described_class.new(project, user) }
-
-  context 'with mentioned merge requests' do
-    it 'returns a list of sorted merge requests' do
-      allow(issue).to receive(:referenced_merge_requests).with(user).and_return([other_mr, mr])
-
-      mrs, closed_by_mrs = service.execute(issue)
-
-      expect(mrs).to match_array([mr, other_mr])
-      expect(closed_by_mrs).to match_array([])
-    end
-  end
-
-  context 'with closed-by merge requests' do
-    it 'returns a list of sorted merge requests' do
-      allow(issue).to receive(:closed_by_merge_requests).with(user).and_return([other_mr, mr])
-
-      mrs, closed_by_mrs = service.execute(issue)
-
-      expect(mrs).to match_array([])
-      expect(closed_by_mrs).to match_array([mr, other_mr])
-    end
-  end
-end
diff --git a/spec/services/issues/referenced_merge_requests_service_spec.rb b/spec/services/issues/referenced_merge_requests_service_spec.rb
new file mode 100644
index 00000000000..a10893e502f
--- /dev/null
+++ b/spec/services/issues/referenced_merge_requests_service_spec.rb
@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+require 'spec_helper.rb'
+
+describe Issues::ReferencedMergeRequestsService do
+  def create_referencing_mr(attributes = {})
+    create(:merge_request, attributes).tap do |merge_request|
+      create(:note, :system, project: project, noteable: issue, note: merge_request.to_reference(full: true))
+    end
+  end
+
+  def create_closing_mr(attributes = {})
+    create_referencing_mr(attributes).tap do |merge_request|
+      create(:merge_requests_closing_issues, issue: issue, merge_request: merge_request)
+    end
+  end
+
+  set(:user) { create(:user) }
+  set(:project) { create(:project, :public, :repository) }
+  set(:other_project) { create(:project, :public, :repository) }
+  set(:issue) { create(:issue, author: user, project: project) }
+
+  set(:closing_mr) { create_closing_mr(source_project: project) }
+  set(:closing_mr_other_project) { create_closing_mr(source_project: other_project) }
+
+  set(:referencing_mr) { create_referencing_mr(source_project: project, source_branch: 'csv') }
+  set(:referencing_mr_other_project) { create_referencing_mr(source_project: other_project, source_branch: 'csv') }
+
+  let(:service) { described_class.new(project, user) }
+
+  describe '#execute' do
+    it 'returns a list of sorted merge requests' do
+      mrs, closed_by_mrs = service.execute(issue)
+
+      expect(mrs).to eq([closing_mr, referencing_mr, closing_mr_other_project, referencing_mr_other_project])
+      expect(closed_by_mrs).to eq([closing_mr, closing_mr_other_project])
+    end
+  end
+
+  describe '#referenced_merge_requests' do
+    it 'returns the referenced merge requests' do
+      expect(service.referenced_merge_requests(issue)).to match_array([
+                                                                        closing_mr,
+                                                                        closing_mr_other_project,
+                                                                        referencing_mr,
+                                                                        referencing_mr_other_project
+                                                                      ])
+    end
+
+    it 'excludes cross project references if the user cannot read cross project' do
+      allow(Ability).to receive(:allowed?).and_call_original
+      expect(Ability).to receive(:allowed?).with(user, :read_cross_project).at_least(:once).and_return(false)
+
+      expect(service.referenced_merge_requests(issue)).not_to include(closing_mr_other_project)
+      expect(service.referenced_merge_requests(issue)).not_to include(referencing_mr_other_project)
+    end
+  end
+
+  describe '#closed_by_merge_requests' do
+    let(:closed_issue) { build(:issue, :closed, project: project)}
+
+    it 'returns the open merge requests that close this issue' do
+      create_closing_mr(source_project: project, state: 'closed')
+
+      expect(service.closed_by_merge_requests(issue)).to match_array([closing_mr, closing_mr_other_project])
+    end
+
+    it 'returns an empty array when the current issue is closed already' do
+      expect(service.closed_by_merge_requests(closed_issue)).to eq([])
+    end
+  end
+end