Fix bug when trying to cache closed issues from external issue trackers

CHANGELOG

@@ -45,6 +45,7 @@ v 8.13.0 (unreleased)
   - Changed Slack service user referencing from full name to username (Sebastian Poxhofer) 
 
 v 8.12.4 (unreleased)
+  - Fix type mismatch bug when closing Jira issue
 
 v 8.12.3
   - Update Gitlab Shell to support low IO priority for storage moves

app/models/merge_request.rb

@@ -523,9 +523,13 @@ class MergeRequest < ActiveRecord::Base
   # `MergeRequestsClosingIssues` model. This is a performance optimization.
   # Calculating this information for a number of merge requests requires
   # running `ReferenceExtractor` on each of them separately.
+  # This optimization does not apply to issues from external sources.
   def cache_merge_request_closes_issues!(current_user = self.author)
+    return if project.has_external_issue_tracker?
+
     transaction do
       self.merge_requests_closing_issues.delete_all
+
       closes_issues(current_user).each do |issue|
         self.merge_requests_closing_issues.create!(issue: issue)
       end

spec/models/merge_request_spec.rb

@@ -86,6 +86,30 @@ describe MergeRequest, models: true do
     end
   end
 
+  describe '#cache_merge_request_closes_issues!' do
+    before do
+      subject.project.team << [subject.author, :developer]
+      subject.target_branch = subject.project.default_branch
+    end
+
+    it 'caches closed issues' do
+      issue  = create :issue, project: subject.project
+      commit = double('commit1', safe_message: "Fixes #{issue.to_reference}")
+      allow(subject).to receive(:commits).and_return([commit])
+
+      expect { subject.cache_merge_request_closes_issues! }.to change(subject.merge_requests_closing_issues, :count).by(1)
+    end
+
+    it 'does not cache issues from external trackers' do
+      subject.project.update_attribute(:has_external_issue_tracker, true)
+      issue  = ExternalIssue.new('JIRA-123', subject.project)
+      commit = double('commit1', safe_message: "Fixes #{issue.to_reference}")
+      allow(subject).to receive(:commits).and_return([commit])
+
+      expect { subject.cache_merge_request_closes_issues! }.not_to change(subject.merge_requests_closing_issues, :count)
+    end
+  end
+
   describe '#source_branch_sha' do
     let(:last_branch_commit) { subject.source_project.repository.commit(subject.source_branch) }
 

spec/services/merge_requests/merge_service_spec.rb

@@ -38,6 +38,42 @@ describe MergeRequests::MergeService, services: true do
       end
     end
 
+    context 'closes related issues' do
+      let(:service) { described_class.new(project, user, commit_message: 'Awesome message') }
+
+      before do
+        allow(project).to receive(:default_branch).and_return(merge_request.target_branch)
+      end
+
+      it 'closes GitLab issue tracker issues' do
+        issue  = create :issue, project: project
+        commit = double('commit', safe_message: "Fixes #{issue.to_reference}")
+        allow(merge_request).to receive(:commits).and_return([commit])
+
+        service.execute(merge_request)
+
+        expect(issue.reload.closed?).to be_truthy
+      end
+
+      context 'with JIRA integration' do
+        include JiraServiceHelper
+
+        let(:jira_tracker) { project.create_jira_service }
+
+        before { jira_service_settings }
+
+        it 'closes issues on JIRA issue tracker' do
+          jira_issue = ExternalIssue.new('JIRA-123', project)
+          commit = double('commit', safe_message: "Fixes #{jira_issue.to_reference}")
+          allow(merge_request).to receive(:commits).and_return([commit])
+
+          expect_any_instance_of(JiraService).to receive(:close_issue).with(merge_request, jira_issue).once
+
+          service.execute(merge_request)
+        end
+      end
+    end
+
     context 'closes related todos' do
       let(:merge_request) { create(:merge_request, assignee: user, author: user) }
       let(:project) { merge_request.project }