Return empty scans when head_pipeline is nil

Add test for all comparision services
Further refactoring required since code is repeated

ee/app/services/ci/compare_container_scanning_reports_service.rb

@@ -15,7 +15,8 @@ module Ci
     end
 
     def build_comparer(base_pipeline, head_pipeline)
-      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_pipeline.security_scans)
+      head_scans = head_pipeline&.security_scans || Security::Scan.none
+      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_scans)
     end
   end
 end

ee/app/services/ci/compare_dast_reports_service.rb

@@ -15,7 +15,8 @@ module Ci
     end
 
     def build_comparer(base_pipeline, head_pipeline)
-      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_pipeline.security_scans)
+      head_scans = head_pipeline&.security_scans || Security::Scan.none
+      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_scans)
     end
   end
 end

ee/app/services/ci/compare_dependency_scanning_reports_service.rb

@@ -15,7 +15,8 @@ module Ci
     end
 
     def build_comparer(base_pipeline, head_pipeline)
-      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_pipeline.security_scans)
+      head_scans = head_pipeline&.security_scans || Security::Scan.none
+      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_scans)
     end
   end
 end

ee/app/services/ci/compare_sast_reports_service.rb

@@ -15,7 +15,8 @@ module Ci
     end
 
     def build_comparer(base_pipeline, head_pipeline)
-      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_pipeline.security_scans)
+      head_scans = head_pipeline&.security_scans || Security::Scan.none
+      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_scans)
     end
   end
 end

ee/app/services/ci/compare_secret_detection_reports_service.rb

@@ -15,7 +15,8 @@ module Ci
     end
 
     def build_comparer(base_pipeline, head_pipeline)
-      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_pipeline.security_scans)
+      head_scans = head_pipeline&.security_scans || Security::Scan.none
+      comparer_class.new(get_report(base_pipeline), get_report(head_pipeline), head_security_scans: head_scans)
     end
   end
 end

ee/changelogs/unreleased/220948-undefined-security-scans.yml

+---
+title: Return empty scans when head_pipeline is missing
+merge_request: 34193
+author:
+type: fixed

ee/spec/services/ci/compare_container_scanning_reports_service_spec.rb

@@ -60,4 +60,15 @@ describe Ci::CompareContainerScanningReportsService do
       end
     end
   end
+
+  describe "#build_comparer" do
+    context "when the head_pipeline is nil" do
+      subject { service.build_comparer(base_pipeline, nil) }
+
+      let(:base_pipeline) { create(:ee_ci_pipeline) }
+
+      specify { expect { subject }.not_to raise_error }
+      specify { expect(subject.scans).to be_empty }
+    end
+  end
 end

ee/spec/services/ci/compare_dast_reports_service_spec.rb

@@ -69,5 +69,16 @@ describe Ci::CompareDastReportsService do
         )
       end
     end
+
+    describe "#build_comparer" do
+      context "when the head_pipeline is nil" do
+        subject { service.build_comparer(base_pipeline, nil) }
+
+        let(:base_pipeline) { create(:ee_ci_pipeline) }
+
+        specify { expect { subject }.not_to raise_error }
+        specify { expect(subject.scans).to be_empty }
+      end
+    end
   end
 end

ee/spec/services/ci/compare_dependency_scanning_reports_service_spec.rb

@@ -83,5 +83,16 @@ describe Ci::CompareDependencyScanningReportsService do
         expect(result[:status_reason]).to include('JSON parsing failed')
       end
     end
+
+    describe "#build_comparer" do
+      context "when the head_pipeline is nil" do
+        subject { service.build_comparer(base_pipeline, nil) }
+
+        let(:base_pipeline) { create(:ee_ci_pipeline) }
+
+        specify { expect { subject }.not_to raise_error }
+        specify { expect(subject.scans).to be_empty }
+      end
+    end
   end
 end

ee/spec/services/ci/compare_sast_reports_service_spec.rb

@@ -61,5 +61,16 @@ describe Ci::CompareSastReportsService do
         expect(compare_keys - expected_keys).to eq([])
       end
     end
+
+    describe "#build_comparer" do
+      context "when the head_pipeline is nil" do
+        subject { service.build_comparer(base_pipeline, nil) }
+
+        let(:base_pipeline) { create(:ee_ci_pipeline) }
+
+        specify { expect { subject }.not_to raise_error }
+        specify { expect(subject.scans).to be_empty }
+      end
+    end
   end
 end

ee/spec/services/ci/compare_secret_detection_reports_service_spec.rb

@@ -57,5 +57,16 @@ RSpec.describe Ci::CompareSecretDetectionReportsService do
         expect(compare_keys - expected_keys).to eq([])
       end
     end
+
+    describe '#build_comparer' do
+      context 'when the head_pipeline is nil' do
+        subject { service.build_comparer(base_pipeline, nil) }
+
+        let(:base_pipeline) { create(:ee_ci_pipeline) }
+
+        specify { expect { subject }.not_to raise_error }
+        specify { expect(subject.scans).to be_empty }
+      end
+    end
   end
 end