Adjust Issue references pluralization on success message

app/services/related_issues/create_service.rb

@@ -15,7 +15,7 @@ module RelatedIssues
         return error(exception.message, 401)
       end
 
-      success(message: "#{issues_sentence(referenced_issues)} were successfully related")
+      success_message
     end
 
     private
@@ -50,6 +50,12 @@ module RelatedIssues
       end
     end
 
+    def success_message
+      verb = referenced_issues.size > 1 ? 'were' : 'was'
+
+      success(message: "#{issues_sentence(referenced_issues)} #{verb} successfully related")
+    end
+
     def issues_sentence(issues)
       issues.map { |issue| issue.to_reference(@issue.project) }.sort.to_sentence
     end

spec/services/related_issues/create_service_spec.rb

@@ -16,7 +16,7 @@ describe RelatedIssues::CreateService, service: true do
 
     subject { described_class.new(issue, user, params).execute }
 
-    context 'when issue not found' do
+    context 'when Issue not found' do
       let(:params) do
         { issue_references: ['#999'] }
       end
@@ -46,7 +46,7 @@ describe RelatedIssues::CreateService, service: true do
       end
     end
 
-    context 'when all Issue references are valid' do
+    context 'when any Issue to relate' do
       let(:issue_a) { create :issue, project: project }
       let(:another_project) { create :empty_project, namespace: project.namespace }
       let(:another_project_issue) { create :issue, project: another_project }
@@ -69,7 +69,7 @@ describe RelatedIssues::CreateService, service: true do
         expect(RelatedIssue.last).to have_attributes(issue: issue, related_issue: another_project_issue)
       end
 
-      it 'returns success message with Issue references' do
+        it 'returns success message with Issue reference' do
           is_expected.to eq(message: "#{issue_a_ref} and #{another_project_issue_ref} were successfully related", status: :success)
         end
 
@@ -90,6 +90,39 @@ describe RelatedIssues::CreateService, service: true do
       end
     end
 
+    context 'success message' do
+      let(:issue_a) { create :issue, project: project }
+      let(:another_project) { create :empty_project, namespace: project.namespace }
+      let(:another_project_issue) { create :issue, project: another_project }
+
+      let(:issue_a_ref) { issue_a.to_reference }
+      let(:another_project_issue_ref) { another_project_issue.to_reference(project) }
+
+      before do
+        another_project.team << [user, :developer]
+      end
+
+      context 'multiple Issues relation' do
+        let(:params) do
+          { issue_references: [issue_a_ref, another_project_issue_ref] }
+        end
+
+        it 'returns success message with Issue reference' do
+          is_expected.to eq(message: "#{issue_a_ref} and #{another_project_issue_ref} were successfully related", status: :success)
+        end
+      end
+
+      context 'single Issue relation' do
+        let(:params) do
+          { issue_references: [issue_a_ref] }
+        end
+
+        it 'returns success message with Issue reference' do
+          is_expected.to eq(message: "#{issue_a_ref} was successfully related", status: :success)
+        end
+      end
+    end
+
     context 'when relation already exists' do
       let(:issue_a) { create :issue, project: project }
       let(:issue_b) { create :issue, project: project }