Moving EE Pipeline code into EE::Ci::Pipeline

- Moved the :merge_train logic branch of
  Ci::Pipeline#merge_request_event_type into EE
- Added specs for EE::Ci::Pipeline to include base and EE cases

app/models/ci/pipeline.rb

@@ -772,18 +772,10 @@ module Ci
       triggered_by_merge_request? && target_sha.present?
     end
 
-    def merge_train_pipeline?
-      merge_request_pipeline? && merge_train_ref?
-    end
-
     def merge_request_ref?
       MergeRequest.merge_request_ref?(ref)
     end
 
-    def merge_train_ref?
-      MergeRequest.merge_train_ref?(ref)
-    end
-
     def matches_sha_or_source_sha?(sha)
       self.sha == sha || self.source_sha == sha
     end
@@ -816,9 +808,7 @@ module Ci
       return unless merge_request_event?
 
       strong_memoize(:merge_request_event_type) do
-        if merge_train_pipeline?
-          :merge_train
-        elsif merge_request_pipeline?
+        if merge_request_pipeline?
           :merged_result
         elsif detached_merge_request_pipeline?
           :detached

ee/app/models/ee/ci/pipeline.rb

@@ -4,6 +4,7 @@ module EE
   module Ci
     module Pipeline
       extend ActiveSupport::Concern
+      extend ::Gitlab::Utils::Override
 
       BridgeStatusError = Class.new(StandardError)
 
@@ -167,8 +168,25 @@ module EE
           target_sha == merge_request.target_branch_sha
       end
 
+      override :merge_request_event_type
+      def merge_request_event_type
+        return unless merge_request_event?
+
+        strong_memoize(:merge_request_event_type) do
+          merge_train_pipeline? ? :merge_train : super
+        end
+      end
+
+      def merge_train_pipeline?
+        merge_request_pipeline? && merge_train_ref?
+      end
+
       private
 
+      def merge_train_ref?
+        ::MergeRequest.merge_train_ref?(ref)
+      end
+
       # This batch loads the latest reports for each CI job artifact
       # type (e.g. sast, dast, etc.) in a single SQL query to eliminate
       # the need to do N different `job_artifacts.where(file_type:

ee/spec/models/ci/pipeline_spec.rb

@@ -521,4 +521,47 @@ describe Ci::Pipeline do
       it { is_expected.to be false }
     end
   end
+
+  describe '#merge_train_pipeline?' do
+    subject { pipeline.merge_train_pipeline? }
+
+    let!(:pipeline) do
+      create(:ci_pipeline, source: :merge_request_event, merge_request: merge_request, ref: ref, target_sha: 'xxx')
+    end
+
+    let(:merge_request) { create(:merge_request) }
+    let(:ref) { 'refs/merge-requests/1/train' }
+
+    it { is_expected.to be_truthy }
+
+    context 'when ref is merge ref' do
+      let(:ref) { 'refs/merge-requests/1/merge' }
+
+      it { is_expected.to be_falsy }
+    end
+  end
+
+  describe '#merge_request_event_type' do
+    subject { pipeline.merge_request_event_type }
+
+    let(:pipeline) { merge_request.all_pipelines.last }
+
+    context 'when pipeline is merge train pipeline' do
+      let(:merge_request) { create(:merge_request, :with_merge_train_pipeline) }
+
+      it { is_expected.to eq(:merge_train) }
+    end
+
+    context 'when pipeline is merge request pipeline' do
+      let(:merge_request) { create(:merge_request, :with_merge_request_pipeline) }
+
+      it { is_expected.to eq(:merged_result) }
+    end
+
+    context 'when pipeline is detached merge request pipeline' do
+      let(:merge_request) { create(:merge_request, :with_detached_merge_request_pipeline) }
+
+      it { is_expected.to eq(:detached) }
+    end
+  end
 end

spec/models/ci/pipeline_spec.rb

@@ -199,25 +199,6 @@ describe Ci::Pipeline, :mailer do
     end
   end
 
-  describe '#merge_train_pipeline?' do
-    subject { pipeline.merge_train_pipeline? }
-
-    let!(:pipeline) do
-      create(:ci_pipeline, source: :merge_request_event, merge_request: merge_request, ref: ref, target_sha: 'xxx')
-    end
-
-    let(:merge_request) { create(:merge_request) }
-    let(:ref) { 'refs/merge-requests/1/train' }
-
-    it { is_expected.to be_truthy }
-
-    context 'when ref is merge ref' do
-      let(:ref) { 'refs/merge-requests/1/merge' }
-
-      it { is_expected.to be_falsy }
-    end
-  end
-
   describe '#merge_request_ref?' do
     subject { pipeline.merge_request_ref? }
 
@@ -228,43 +209,19 @@ describe Ci::Pipeline, :mailer do
     end
   end
 
-  describe '#merge_train_ref?' do
-    subject { pipeline.merge_train_ref? }
-
-    it 'calls Mergetrain#merge_train_ref?' do
-      expect(MergeRequest).to receive(:merge_train_ref?).with(pipeline.ref)
-
-      subject
-    end
-  end
-
   describe '#merge_request_event_type' do
     subject { pipeline.merge_request_event_type }
 
-    before do
-      allow(pipeline).to receive(:merge_request_event?) { true }
-    end
-
-    context 'when pipeline is merge train pipeline' do
-      before do
-        allow(pipeline).to receive(:merge_train_pipeline?) { true }
-      end
-
-      it { is_expected.to eq(:merge_train) }
-    end
+    let(:pipeline) { merge_request.all_pipelines.last }
 
     context 'when pipeline is merge request pipeline' do
-      before do
-        allow(pipeline).to receive(:merge_request_pipeline?) { true }
-      end
+      let(:merge_request) { create(:merge_request, :with_merge_request_pipeline) }
 
       it { is_expected.to eq(:merged_result) }
     end
 
     context 'when pipeline is detached merge request pipeline' do
-      before do
-        allow(pipeline).to receive(:detached_merge_request_pipeline?) { true }
-      end
+      let(:merge_request) { create(:merge_request, :with_detached_merge_request_pipeline) }
 
       it { is_expected.to eq(:detached) }
     end