Split AutoMergeService interfaces into two `cancel` and `abort`

Create explicit endpoint - abort.

4 files changed, 87 insertions, 5 deletions

diff --git a/spec/services/auto_merge/base_service_spec.rb b/spec/services/auto_merge/base_service_spec.rb
index 24cb63a0d61..a409f21a7e4 100644
--- a/spec/services/auto_merge/base_service_spec.rb
+++ b/spec/services/auto_merge/base_service_spec.rb
@@ -121,11 +121,7 @@ describe AutoMerge::BaseService do
     end
   end
 
-  describe '#cancel' do
-    subject { service.cancel(merge_request) }
-
-    let(:merge_request) { create(:merge_request, :merge_when_pipeline_succeeds) }
-
+  shared_examples_for 'Canceled or Dropped' do
     it 'removes properies from the merge request' do
       subject
 
@@ -173,6 +169,20 @@ describe AutoMerge::BaseService do
       it 'does not yield block' do
         expect { |b| service.execute(merge_request, &b) }.not_to yield_control
       end
+    end
+  end
+
+  describe '#cancel' do
+    subject { service.cancel(merge_request) }
+
+    let(:merge_request) { create(:merge_request, :merge_when_pipeline_succeeds) }
+
+    it_behaves_like 'Canceled or Dropped'
+
+    context 'when failed to save' do
+      before do
+        allow(merge_request).to receive(:save) { false }
+      end
 
       it 'returns error status' do
         expect(subject[:status]).to eq(:error)
@@ -180,4 +190,24 @@ describe AutoMerge::BaseService do
       end
     end
   end
+
+  describe '#abort' do
+    subject { service.abort(merge_request, reason) }
+
+    let(:merge_request) { create(:merge_request, :merge_when_pipeline_succeeds) }
+    let(:reason) { 'an error'}
+
+    it_behaves_like 'Canceled or Dropped'
+
+    context 'when failed to save' do
+      before do
+        allow(merge_request).to receive(:save) { false }
+      end
+
+      it 'returns error status' do
+        expect(subject[:status]).to eq(:error)
+        expect(subject[:message]).to eq("Can't abort the automatic merge")
+      end
+    end
+  end
 end
diff --git a/spec/services/auto_merge/merge_when_pipeline_succeeds_service_spec.rb b/spec/services/auto_merge/merge_when_pipeline_succeeds_service_spec.rb
index 5e84ef052ce..931b52470c4 100644
--- a/spec/services/auto_merge/merge_when_pipeline_succeeds_service_spec.rb
+++ b/spec/services/auto_merge/merge_when_pipeline_succeeds_service_spec.rb
@@ -177,6 +177,17 @@ describe AutoMerge::MergeWhenPipelineSucceedsService do
     end
   end
 
+  describe "#abort" do
+    before do
+      service.abort(mr_merge_if_green_enabled, 'an error')
+    end
+
+    it 'posts a system note' do
+      note = mr_merge_if_green_enabled.notes.last
+      expect(note.note).to include 'aborted the automatic merge'
+    end
+  end
+
   describe 'pipeline integration' do
     context 'when there are multiple stages in the pipeline' do
       let(:ref) { mr_merge_if_green_enabled.source_branch }
diff --git a/spec/services/auto_merge_service_spec.rb b/spec/services/auto_merge_service_spec.rb
index 93a22e60498..50dfc49a59c 100644
--- a/spec/services/auto_merge_service_spec.rb
+++ b/spec/services/auto_merge_service_spec.rb
@@ -161,4 +161,29 @@ describe AutoMergeService do
       end
     end
   end
+
+  describe '#abort' do
+    subject { service.abort(merge_request, error) }
+
+    let(:merge_request) { create(:merge_request, :merge_when_pipeline_succeeds) }
+    let(:error) { 'an error' }
+
+    it 'delegates to a relevant service instance' do
+      expect_next_instance_of(AutoMerge::MergeWhenPipelineSucceedsService) do |service|
+        expect(service).to receive(:abort).with(merge_request, error)
+      end
+
+      subject
+    end
+
+    context 'when auto merge is not enabled' do
+      let(:merge_request) { create(:merge_request) }
+
+      it 'returns error' do
+        expect(subject[:message]).to eq("Can't abort the automatic merge")
+        expect(subject[:status]).to eq(:error)
+        expect(subject[:http_status]).to eq(406)
+      end
+    end
+  end
 end
diff --git a/spec/services/system_note_service_spec.rb b/spec/services/system_note_service_spec.rb
index 9f60e49290e..2d33e1c37eb 100644
--- a/spec/services/system_note_service_spec.rb
+++ b/spec/services/system_note_service_spec.rb
@@ -359,6 +359,22 @@ describe SystemNoteService do
     end
   end
 
+  describe '.abort_merge_when_pipeline_succeeds' do
+    let(:noteable) do
+      create(:merge_request, source_project: project, target_project: project)
+    end
+
+    subject { described_class.abort_merge_when_pipeline_succeeds(noteable, project, author, 'merge request was closed') }
+
+    it_behaves_like 'a system note' do
+      let(:action) { 'merge' }
+    end
+
+    it "posts the 'merge when pipeline succeeds' system note" do
+      expect(subject.note).to eq "aborted the automatic merge because merge request was closed"
+    end
+  end
+
   describe '.change_title' do
     let(:noteable) { create(:issue, project: project, title: 'Lorem ipsum') }