Add MergeReportsService spec for location deduplication

ee/spec/services/security/merge_reports_service_spec.rb

@@ -40,6 +40,15 @@ RSpec.describe Security::MergeReportsService, '#execute' do
          )
   end
 
+  let(:finding_id_2_loc_1_extra) do
+    build(:ci_reports_security_finding,
+          identifiers: [identifier_2_primary, identifier_2_cve],
+          location: build(:ci_reports_security_locations_sast, start_line: 32, end_line: 34),
+          scanner: scanner_2,
+          severity: :medium
+         )
+  end
+
   let(:finding_id_2_loc_2) do
     build(:ci_reports_security_finding,
           identifiers: [identifier_2_primary, identifier_2_cve],
@@ -81,7 +90,7 @@ RSpec.describe Security::MergeReportsService, '#execute' do
          )
   end
 
-  let(:report_1_findings) { [finding_id_1, finding_id_2_loc_1, finding_cwe_2, finding_wasc_1] }
+  let(:report_1_findings) { [finding_id_1, finding_id_2_loc_1, finding_id_2_loc_1_extra, finding_cwe_2, finding_wasc_1] }
 
   let(:scanned_resource) do
     ::Gitlab::Ci::Reports::Security::ScannedResource.new(URI.parse('example.com'), 'GET')