1 files changed, 95 insertions, 0 deletions
diff --git a/spec/services/merge_requests/mergeability_check_service_spec.rb b/spec/services/merge_requests/mergeability_check_service_spec.rb
index 6ad079d5f28..aa0485467ed 100644
--- a/spec/services/merge_requests/mergeability_check_service_spec.rb
+++ b/spec/services/merge_requests/mergeability_check_service_spec.rb
@@ -39,6 +39,14 @@ describe MergeRequests::MergeabilityCheckService do
       expect(result).to be_a(ServiceResponse)
       expect(result).to be_success
     end
+
+    it 'ServiceResponse has merge_ref_head payload' do
+      result = subject
+
+      expect(result.payload.keys).to contain_exactly(:merge_ref_head)
+      expect(result.payload[:merge_ref_head].keys)
+        .to contain_exactly(:commit_id, :target_id, :source_id)
+    end
   end
 
   describe '#execute' do
@@ -54,6 +62,21 @@ describe MergeRequests::MergeabilityCheckService do
 
     it_behaves_like 'mergeable merge request'
 
+    context 'when multiple calls to the service' do
+      it 'returns success' do
+        subject
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.success?).to be(true)
+      end
+
+      it 'second call does not change the merge-ref' do
+        expect { subject }.to change(merge_request, :merge_ref_head).from(nil)
+        expect { subject }.not_to change(merge_request, :merge_ref_head)
+      end
+    end
+
     context 'when broken' do
       before do
         allow(merge_request).to receive(:broken?) { true }
@@ -61,6 +84,14 @@ describe MergeRequests::MergeabilityCheckService do
       end
 
       it_behaves_like 'unmergeable merge request'
+
+      it 'returns ServiceResponse.error' do
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.error?).to be(true)
+        expect(result.message).to eq('Merge request is not mergeable')
+      end
     end
 
     context 'when it has conflicts' do
@@ -70,6 +101,14 @@ describe MergeRequests::MergeabilityCheckService do
       end
 
       it_behaves_like 'unmergeable merge request'
+
+      it 'returns ServiceResponse.error' do
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.error?).to be(true)
+        expect(result.message).to eq('Merge request is not mergeable')
+      end
     end
 
     context 'when MR cannot be merged and has no merge ref' do
@@ -78,6 +117,14 @@ describe MergeRequests::MergeabilityCheckService do
       end
 
       it_behaves_like 'unmergeable merge request'
+
+      it 'returns ServiceResponse.error' do
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.error?).to be(true)
+        expect(result.message).to eq('Merge request is not mergeable')
+      end
     end
 
     context 'when MR cannot be merged and has outdated merge ref' do
@@ -87,6 +134,54 @@ describe MergeRequests::MergeabilityCheckService do
       end
 
       it_behaves_like 'unmergeable merge request'
+
+      it 'returns ServiceResponse.error' do
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.error?).to be(true)
+        expect(result.message).to eq('Merge request is not mergeable')
+      end
+    end
+
+    context 'when merge request is not given' do
+      subject { described_class.new(nil).execute }
+
+      it 'returns ServiceResponse.error' do
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.message).to eq('Invalid argument')
+      end
+    end
+
+    context 'when read only DB' do
+      it 'returns ServiceResponse.error' do
+        allow(Gitlab::Database).to receive(:read_only?) { true }
+
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.message).to eq('Unsupported operation')
+      end
+    end
+
+    context 'when MR is mergeable but merge-ref does not exists' do
+      before do
+        merge_request.mark_as_mergeable!
+      end
+
+      it 'keeps merge status as can_be_merged' do
+        expect { subject }.not_to change(merge_request, :merge_status).from('can_be_merged')
+      end
+
+      it 'returns ServiceResponse.error' do
+        result = subject
+
+        expect(result).to be_a(ServiceResponse)
+        expect(result.error?).to be(true)
+        expect(result.message).to eq('Merge ref was not found')
+      end
     end
   end
 end