Merge branch 'eb-cobertura-background-fix' into 'master'

Implement smart cobertura class path correction

See merge request gitlab-org/gitlab!48048

app/models/ci/build.rb

@@ -916,8 +916,20 @@ module Ci
     end
 
     def collect_coverage_reports!(coverage_report)
+      project_path, worktree_paths = if Feature.enabled?(:smart_cobertura_parser, project)
+                                       # If the flag is disabled, we intentionally pass nil
+                                       # for both project_path and worktree_paths to fallback
+                                       # to the non-smart behavior of the parser
+                                       [project.full_path, pipeline.all_worktree_paths]
+                                     end
+
       each_report(Ci::JobArtifact::COVERAGE_REPORT_FILE_TYPES) do |file_type, blob|
-        Gitlab::Ci::Parsers.fabricate!(file_type).parse!(blob, coverage_report)
+        Gitlab::Ci::Parsers.fabricate!(file_type).parse!(
+          blob,
+          coverage_report,
+          project_path: project_path,
+          worktree_paths: worktree_paths
+        )
       end
 
       coverage_report

app/models/ci/pipeline.rb

@@ -972,7 +972,7 @@ module Ci
 
     def coverage_reports
       Gitlab::Ci::Reports::CoverageReports.new.tap do |coverage_reports|
-        latest_report_builds(Ci::JobArtifact.coverage_reports).each do |build|
+        latest_report_builds(Ci::JobArtifact.coverage_reports).includes(:project).find_each do |build|
           build.collect_coverage_reports!(coverage_reports)
         end
       end

changelogs/unreleased/eb-cobertura-background-fix.yml

+---
+title: Implement smart cobertura class path correction
+merge_request: 48048
+author:
+type: changed

config/feature_flags/development/smart_cobertura_parser.yml

+---
+name: smart_cobertura_parser
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/48048
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/284822
+milestone: '13.7'
+type: development
+group: group::testing
+default_enabled: false

lib/gitlab/ci/parsers/coverage/cobertura.rb

@@ -5,50 +5,113 @@ module Gitlab
     module Parsers
       module Coverage
         class Cobertura
-          CoberturaParserError = Class.new(Gitlab::Ci::Parsers::ParserError)
+          InvalidXMLError = Class.new(Gitlab::Ci::Parsers::ParserError)
+          InvalidLineInformationError = Class.new(Gitlab::Ci::Parsers::ParserError)
 
-          def parse!(xml_data, coverage_report)
+          GO_SOURCE_PATTERN = '/usr/local/go/src'
+          MAX_SOURCES = 100
+
+          def parse!(xml_data, coverage_report, project_path: nil, worktree_paths: nil)
             root = Hash.from_xml(xml_data)
 
-            parse_all(root, coverage_report)
+            context = {
+              project_path: project_path,
+              paths: worktree_paths&.to_set,
+              sources: []
+            }
+
+            parse_all(root, coverage_report, context)
           rescue Nokogiri::XML::SyntaxError
-            raise CoberturaParserError, "XML parsing failed"
-          rescue
-            raise CoberturaParserError, "Cobertura parsing failed"
+            raise InvalidXMLError, "XML parsing failed"
           end
 
           private
 
-          def parse_all(root, coverage_report)
+          def parse_all(root, coverage_report, context)
             return unless root.present?
 
             root.each do |key, value|
-              parse_node(key, value, coverage_report)
+              parse_node(key, value, coverage_report, context)
             end
           end
 
-          def parse_node(key, value, coverage_report)
-            return if key == 'sources'
-
-            if key == 'class'
+          def parse_node(key, value, coverage_report, context)
+            if key == 'sources' && value['source'].present?
+              parse_sources(value['source'], context)
+            elsif key == 'package'
               Array.wrap(value).each do |item|
-                parse_class(item, coverage_report)
+                parse_package(item, coverage_report, context)
+              end
+            elsif key == 'class'
+              # This means the cobertura XML does not have classes within package nodes.
+              # This is possible in some cases like in simple JS project structures
+              # running Jest.
+              Array.wrap(value).each do |item|
+                parse_class(item, coverage_report, context)
               end
             elsif value.is_a?(Hash)
-              parse_all(value, coverage_report)
+              parse_all(value, coverage_report, context)
             elsif value.is_a?(Array)
               value.each do |item|
-                parse_all(item, coverage_report)
+                parse_all(item, coverage_report, context)
               end
             end
           end
 
-          def parse_class(file, coverage_report)
+          def parse_sources(sources, context)
+            return unless context[:project_path] && context[:paths]
+
+            sources = Array.wrap(sources)
+
+            # TODO: Go cobertura has a different format with how their packages
+            # are included in the filename. So we can't rely on the sources.
+            # We'll deal with this later.
+            return if sources.include?(GO_SOURCE_PATTERN)
+
+            sources.each do |source|
+              source = build_source_path(source, context)
+              context[:sources] << source if source.present?
+            end
+          end
+
+          def build_source_path(source, context)
+            # | raw source                  | extracted  |
+            # |-----------------------------|------------|
+            # | /builds/foo/test/SampleLib/ | SampleLib/ |
+            # | /builds/foo/test/something  | something  |
+            # | /builds/foo/test/           | nil        |
+            # | /builds/foo/test            | nil        |
+            source.split("#{context[:project_path]}/", 2)[1]
+          end
+
+          def parse_package(package, coverage_report, context)
+            classes = package.dig('classes', 'class')
+            return unless classes.present?
+
+            matched_filenames = Array.wrap(classes).map do |item|
+              parse_class(item, coverage_report, context)
+            end
+
+            # Remove these filenames from the paths to avoid conflict
+            # with other packages that may contain the same class filenames
+            remove_matched_filenames(matched_filenames, context)
+          end
+
+          def remove_matched_filenames(filenames, context)
+            return unless context[:paths]
+
+            filenames.each { |f| context[:paths].delete(f) }
+          end
+
+          def parse_class(file, coverage_report, context)
             return unless file["filename"].present? && file["lines"].present?
 
             parsed_lines = parse_lines(file["lines"])
+            filename = determine_filename(file["filename"], context)
+
+            coverage_report.add_file(filename, Hash[parsed_lines]) if filename
 
-            coverage_report.add_file(file["filename"], Hash[parsed_lines])
+            filename
           end
 
           def parse_lines(lines)
@@ -58,6 +121,27 @@ module Gitlab
               # Using `Integer()` here to raise exception on invalid values
               [Integer(line["number"]), Integer(line["hits"])]
             end
+          rescue
+            raise InvalidLineInformationError, "Line information had invalid values"
+          end
+
+          def determine_filename(filename, context)
+            return filename unless context[:sources].any?
+
+            full_filename = nil
+
+            context[:sources].each_with_index do |source, index|
+              break if index >= MAX_SOURCES
+              break if full_filename = check_source(source, filename, context)
+            end
+
+            full_filename
+          end
+
+          def check_source(source, filename, context)
+            full_path = File.join(source, filename)
+
+            return full_path if context[:paths].include?(full_path)
           end
         end
       end

spec/factories/ci/job_artifacts.rb

@@ -229,6 +229,16 @@ FactoryBot.define do
       end
     end
 
+    trait :coverage_with_paths_not_relative_to_project_root do
+      file_type { :cobertura }
+      file_format { :gzip }
+
+      after(:build) do |artifact, evaluator|
+        artifact.file = fixture_file_upload(
+          Rails.root.join('spec/fixtures/cobertura/coverage_with_paths_not_relative_to_project_root.xml.gz'), 'application/x-gzip')
+      end
+    end
+
     trait :coverage_with_corrupted_data do
       file_type { :cobertura }
       file_format { :gzip }

spec/lib/gitlab/ci/parsers/coverage/cobertura_spec.rb

@@ -4,207 +4,690 @@ require 'fast_spec_helper'
 
 RSpec.describe Gitlab::Ci::Parsers::Coverage::Cobertura do
   describe '#parse!' do
-    subject { described_class.new.parse!(cobertura, coverage_report) }
+    subject(:parse_report) { described_class.new.parse!(cobertura, coverage_report, project_path: project_path, worktree_paths: paths) }
 
     let(:coverage_report) { Gitlab::Ci::Reports::CoverageReports.new }
+    let(:project_path) { 'foo/bar' }
+    let(:paths) { ['app/user.rb'] }
+
+    let(:cobertura) do
+      <<~EOF
+      <coverage>
+        #{sources_xml}
+        #{classes_xml}
+      </coverage>
+      EOF
+    end
 
     context 'when data is Cobertura style XML' do
-      context 'when there is no <class>' do
-        let(:cobertura) { '' }
+      shared_examples_for 'ignoring sources, project_path, and worktree_paths' do
+        context 'when there is no <class>' do
+          let(:classes_xml) { '' }
 
-        it 'parses XML and returns empty coverage' do
-          expect { subject }.not_to raise_error
+          it 'parses XML and returns empty coverage' do
+            expect { parse_report }.not_to raise_error
 
-          expect(coverage_report.files).to eq({})
+            expect(coverage_report.files).to eq({})
+          end
         end
-      end
 
-      context 'when there is a <sources>' do
-        shared_examples_for 'ignoring sources' do
-          it 'parses XML without errors' do
-            expect { subject }.not_to raise_error
+        context 'when there is a single <class>' do
+          context 'with no lines' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns empty coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({})
+            end
+          end
 
-            expect(coverage_report.files).to eq({})
+          context 'with a single line' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns a single file with coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2 } })
+            end
+          end
+
+          context 'without a package parent' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages>
+                <class filename="app.rb"><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+              </packages>
+              EOF
+            end
+
+            it 'parses XML and returns a single file with coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2 } })
+            end
+          end
+
+          context 'with multiple lines and methods info' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="2"/>
+                  <line number="2" hits="0"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns a single file with coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2, 2 => 0 } })
+            end
           end
         end
 
-        context 'and has a single source' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
+        context 'when there are multiple <class>' do
+          context 'without a package parent' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+                <class filename="foo.rb"><methods/><lines>
+                  <line number="6" hits="1"/>
+                </lines></class>
+              </packages>
+              EOF
+            end
+
+            it 'parses XML and returns coverage information per class' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2 }, 'foo.rb' => { 6 => 1 } })
+            end
+          end
+
+          context 'with the same filename and different lines' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="2"/>
+                  <line number="2" hits="0"/>
+                </lines></class>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="6" hits="1"/>
+                  <line number="7" hits="1"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns a single file with merged coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2, 2 => 0, 6 => 1, 7 => 1 } })
+            end
+          end
+
+          context 'with the same filename and lines' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="2"/>
+                  <line number="2" hits="0"/>
+                </lines></class>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="1"/>
+                  <line number="2" hits="1"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns a single file with summed-up coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 3, 2 => 1 } })
+            end
+          end
+
+          context 'with missing filename' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="2"/>
+                  <line number="2" hits="0"/>
+                </lines></class>
+                <class><methods/><lines>
+                  <line number="6" hits="1"/>
+                  <line number="7" hits="1"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and ignores class with missing name' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2, 2 => 0 } })
+            end
+          end
+
+          context 'with invalid line information' do
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="app.rb"><methods/><lines>
+                  <line number="1" hits="2"/>
+                  <line number="2" hits="0"/>
+                </lines></class>
+                <class filename="app.rb"><methods/><lines>
+                  <line null="test" hits="1"/>
+                  <line number="7" hits="1"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'raises an error' do
+              expect { parse_report }.to raise_error(described_class::InvalidLineInformationError)
+            end
+          end
+        end
+      end
+
+      context 'when there is no <sources>' do
+        let(:sources_xml) { '' }
+
+        it_behaves_like 'ignoring sources, project_path, and worktree_paths'
+      end
+
+      context 'when there is a <sources>' do
+        context 'and has a single source with a pattern for Go projects' do
+          let(:project_path) { 'local/go' } # Make sure we're not making false positives
+          let(:sources_xml) do
+            <<~EOF
             <sources>
-              <source>project/src</source>
+              <source>/usr/local/go/src</source>
             </sources>
             EOF
           end
 
-          it_behaves_like 'ignoring sources'
+          it_behaves_like 'ignoring sources, project_path, and worktree_paths'
         end
 
-        context 'and has multiple sources' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
+        context 'and has multiple sources with a pattern for Go projects' do
+          let(:project_path) { 'local/go' } # Make sure we're not making false positives
+          let(:sources_xml) do
+            <<~EOF
             <sources>
-              <source>project/src/foo</source>
-              <source>project/src/bar</source>
+              <source>/usr/local/go/src</source>
+              <source>/go/src</source>
             </sources>
             EOF
           end
 
-          it_behaves_like 'ignoring sources'
+          it_behaves_like 'ignoring sources, project_path, and worktree_paths'
         end
-      end
 
-      context 'when there is a single <class>' do
-        context 'with no lines' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <classes><class filename="app.rb"></class></classes>
+        context 'and has a single source but already is at the project root path' do
+          let(:sources_xml) do
+            <<~EOF
+            <sources>
+              <source>builds/#{project_path}</source>
+            </sources>
             EOF
           end
 
-          it 'parses XML and returns empty coverage' do
-            expect { subject }.not_to raise_error
+          it_behaves_like 'ignoring sources, project_path, and worktree_paths'
+        end
 
-            expect(coverage_report.files).to eq({})
+        context 'and has multiple sources but already are at the project root path' do
+          let(:sources_xml) do
+            <<~EOF
+            <sources>
+              <source>builds/#{project_path}/</source>
+              <source>builds/somewhere/#{project_path}</source>
+            </sources>
+            EOF
           end
+
+          it_behaves_like 'ignoring sources, project_path, and worktree_paths'
         end
 
-        context 'with a single line' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <classes>
-              <class filename="app.rb"><lines>
-                <line number="1" hits="2"/>
-              </lines></class>
-            </classes>
+        context 'and has a single source that is not at the project root path' do
+          let(:sources_xml) do
+            <<~EOF
+            <sources>
+              <source>builds/#{project_path}/app</source>
+            </sources>
             EOF
           end
 
-          it 'parses XML and returns a single file with coverage' do
-            expect { subject }.not_to raise_error
+          context 'when there is no <class>' do
+            let(:classes_xml) { '' }
 
-            expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2 } })
-          end
-        end
+            it 'parses XML and returns empty coverage' do
+              expect { parse_report }.not_to raise_error
 
-        context 'with multipe lines and methods info' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <classes>
-              <class filename="app.rb"><methods/><lines>
-                <line number="1" hits="2"/>
-                <line number="2" hits="0"/>
-              </lines></class>
-            </classes>
-            EOF
+              expect(coverage_report.files).to eq({})
+            end
           end
 
-          it 'parses XML and returns a single file with coverage' do
-            expect { subject }.not_to raise_error
+          context 'when there is a single <class>' do
+            context 'with no lines' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns empty coverage' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({})
+              end
+            end
+
+            context 'with a single line but the filename cannot be determined based on extracted source and worktree paths' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="member.rb"><lines>
+                    <line number="1" hits="2"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns empty coverage' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({})
+              end
+            end
+
+            context 'with a single line' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><lines>
+                    <line number="1" hits="2"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns a single file with the filename relative to project root' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 2 } })
+              end
+            end
+
+            context 'with multiple lines and methods info' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns a single file with the filename relative to project root' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 2, 2 => 0 } })
+              end
+            end
+          end
 
-            expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2, 2 => 0 } })
+          context 'when there are multiple <class>' do
+            context 'with the same filename but the filename cannot be determined based on extracted source and worktree paths' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="member.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class filename="member.rb"><methods/><lines>
+                    <line number="6" hits="1"/>
+                    <line number="7" hits="1"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns empty coverage' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({})
+              end
+            end
+
+            context 'without a parent package' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="6" hits="1"/>
+                    <line number="7" hits="1"/>
+                  </lines></class>
+                </packages>
+                EOF
+              end
+
+              it 'parses XML and returns coverage information with the filename relative to project root' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 2, 2 => 0, 6 => 1, 7 => 1 } })
+              end
+            end
+
+            context 'with the same filename and different lines' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="6" hits="1"/>
+                    <line number="7" hits="1"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns a single file with merged coverage, and with the filename relative to project root' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 2, 2 => 0, 6 => 1, 7 => 1 } })
+              end
+            end
+
+            context 'with the same filename and lines' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="1"/>
+                    <line number="2" hits="1"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and returns a single file with summed-up coverage, and with the filename relative to project root' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 3, 2 => 1 } })
+              end
+            end
+
+            context 'with missing filename' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class><methods/><lines>
+                    <line number="6" hits="1"/>
+                    <line number="7" hits="1"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and ignores class with missing name' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 2, 2 => 0 } })
+              end
+            end
+
+            context 'with filename that cannot be determined based on extracted source and worktree paths' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class filename="member.rb"><methods/><lines>
+                    <line number="6" hits="1"/>
+                    <line number="7" hits="1"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'parses XML and ignores class with undetermined filename' do
+                expect { parse_report }.not_to raise_error
+
+                expect(coverage_report.files).to eq({ 'app/user.rb' => { 1 => 2, 2 => 0 } })
+              end
+            end
+
+            context 'with invalid line information' do
+              let(:classes_xml) do
+                <<~EOF
+                <packages><package name="app"><classes>
+                  <class filename="user.rb"><methods/><lines>
+                    <line number="1" hits="2"/>
+                    <line number="2" hits="0"/>
+                  </lines></class>
+                  <class filename="user.rb"><methods/><lines>
+                    <line null="test" hits="1"/>
+                    <line number="7" hits="1"/>
+                  </lines></class>
+                </classes></package></packages>
+                EOF
+              end
+
+              it 'raises an error' do
+                expect { parse_report }.to raise_error(described_class::InvalidLineInformationError)
+              end
+            end
           end
         end
-      end
 
-      context 'when there are multipe <class>' do
-        context 'with the same filename and different lines' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <classes>
-              <class filename="app.rb"><methods/><lines>
-                <line number="1" hits="2"/>
-                <line number="2" hits="0"/>
-              </lines></class>
-              <class filename="app.rb"><methods/><lines>
-                <line number="6" hits="1"/>
-                <line number="7" hits="1"/>
-              </lines></class>
-            </classes>
+        context 'and has multiple sources that are not at the project root path' do
+          let(:sources_xml) do
+            <<~EOF
+            <sources>
+              <source>builds/#{project_path}/app1/</source>
+              <source>builds/#{project_path}/app2/</source>
+            </sources>
             EOF
           end
 
-          it 'parses XML and returns a single file with merged coverage' do
-            expect { subject }.not_to raise_error
-
-            expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2, 2 => 0, 6 => 1, 7 => 1 } })
+          context 'and a class filename is available under multiple extracted sources' do
+            let(:paths) { ['app1/user.rb', 'app2/user.rb'] }
+
+            let(:classes_xml) do
+              <<~EOF
+              <package name="app1">
+                <classes>
+                  <class filename="user.rb"><lines>
+                    <line number="1" hits="2"/>
+                  </lines></class>
+                </classes>
+              </package>
+              <package name="app2">
+                <classes>
+                  <class filename="user.rb"><lines>
+                    <line number="2" hits="3"/>
+                  </lines></class>
+                </classes>
+              </package>
+              EOF
+            end
+
+            it 'parses XML and returns the files with the filename relative to project root' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({
+                'app1/user.rb' => { 1 => 2 },
+                'app2/user.rb' => { 2 => 3 }
+              })
+            end
           end
-        end
 
-        context 'with the same filename and lines' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <packages><package><classes>
-              <class filename="app.rb"><methods/><lines>
-                <line number="1" hits="2"/>
-                <line number="2" hits="0"/>
-              </lines></class>
-              <class filename="app.rb"><methods/><lines>
-                <line number="1" hits="1"/>
-                <line number="2" hits="1"/>
-              </lines></class>
-            </classes></package></packages>
-            EOF
+          context 'and a class filename is available under one of the extracted sources' do
+            let(:paths) { ['app1/member.rb', 'app2/user.rb', 'app2/pet.rb'] }
+
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="user.rb"><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns a single file with the filename relative to project root using the extracted source where it is first found under' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({ 'app2/user.rb' => { 1 => 2 } })
+            end
           end
 
-          it 'parses XML and returns a single file with summed-up coverage' do
-            expect { subject }.not_to raise_error
+          context 'and a class filename is not found under any of the extracted sources' do
+            let(:paths) { ['app1/member.rb', 'app2/pet.rb'] }
 
-            expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 3, 2 => 1 } })
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="user.rb"><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            it 'parses XML and returns empty coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({})
+            end
           end
-        end
 
-        context 'with missing filename' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <classes>
-              <class filename="app.rb"><methods/><lines>
-                <line number="1" hits="2"/>
-                <line number="2" hits="0"/>
-              </lines></class>
-              <class><methods/><lines>
-                <line number="6" hits="1"/>
-                <line number="7" hits="1"/>
-              </lines></class>
-            </classes>
-            EOF
+          context 'and a class filename is not found under any of the extracted sources within the iteratable limit' do
+            let(:paths) { ['app2/user.rb'] }
+
+            let(:classes_xml) do
+              <<~EOF
+              <packages><package name="app"><classes>
+                <class filename="record.rb"><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+                <class filename="user.rb"><lines>
+                  <line number="1" hits="2"/>
+                </lines></class>
+              </classes></package></packages>
+              EOF
+            end
+
+            before do
+              stub_const("#{described_class}::MAX_SOURCES", 1)
+            end
+
+            it 'parses XML and returns empty coverage' do
+              expect { parse_report }.not_to raise_error
+
+              expect(coverage_report.files).to eq({})
+            end
           end
+        end
+      end
 
-          it 'parses XML and ignores class with missing name' do
-            expect { subject }.not_to raise_error
+      shared_examples_for 'non-smart parsing' do
+        let(:sources_xml) do
+          <<~EOF
+          <sources>
+            <source>builds/foo/bar/app</source>
+          </sources>
+          EOF
+        end
 
-            expect(coverage_report.files).to eq({ 'app.rb' => { 1 => 2, 2 => 0 } })
-          end
+        let(:classes_xml) do
+          <<~EOF
+          <packages><package name="app"><classes>
+            <class filename="user.rb"><lines>
+              <line number="1" hits="2"/>
+            </lines></class>
+          </classes></package></packages>
+          EOF
         end
 
-        context 'with invalid line information' do
-          let(:cobertura) do
-            <<-EOF.strip_heredoc
-            <classes>
-              <class filename="app.rb"><methods/><lines>
-                <line number="1" hits="2"/>
-                <line number="2" hits="0"/>
-              </lines></class>
-              <class filename="app.rb"><methods/><lines>
-                <line null="test" hits="1"/>
-                <line number="7" hits="1"/>
-              </lines></class>
-            </classes>
-            EOF
-          end
+        it 'parses XML and returns filenames unchanged just as how they are found in the class node' do
+          expect { parse_report }.not_to raise_error
 
-          it 'raises an error' do
-            expect { subject }.to raise_error(described_class::CoberturaParserError)
-          end
+          expect(coverage_report.files).to eq({ 'user.rb' => { 1 => 2 } })
         end
       end
+
+      context 'when project_path is not present' do
+        let(:project_path) { nil }
+        let(:paths) { ['app/user.rb'] }
+
+        it_behaves_like 'non-smart parsing'
+      end
+
+      context 'when worktree_paths is not present' do
+        let(:project_path) { 'foo/bar' }
+        let(:paths) { nil }
+
+        it_behaves_like 'non-smart parsing'
+      end
     end
 
     context 'when data is not Cobertura style XML' do
       let(:cobertura) { { coverage: '12%' }.to_json }
 
       it 'raises an error' do
-        expect { subject }.to raise_error(described_class::CoberturaParserError)
+        expect { parse_report }.to raise_error(described_class::InvalidXMLError)
       end
     end
   end

spec/models/ci/build_spec.rb

@@ -4059,13 +4059,40 @@ RSpec.describe Ci::Build do
         end
       end
 
+      context 'when there is a Cobertura coverage report with class filename paths not relative to project root' do
+        before do
+          allow(build.project).to receive(:full_path).and_return('root/javademo')
+          allow(build.pipeline).to receive(:all_worktree_paths).and_return(['src/main/java/com/example/javademo/User.java'])
+
+          create(:ci_job_artifact, :coverage_with_paths_not_relative_to_project_root, job: build, project: build.project)
+        end
+
+        it 'parses blobs and add the results to the coverage report with corrected paths' do
+          expect { subject }.not_to raise_error
+
+          expect(coverage_report.files.keys).to match_array(['src/main/java/com/example/javademo/User.java'])
+        end
+
+        context 'and smart_cobertura_parser feature flag is disabled' do
+          before do
+            stub_feature_flags(smart_cobertura_parser: false)
+          end
+
+          it 'parses blobs and add the results to the coverage report with unmodified paths' do
+            expect { subject }.not_to raise_error
+
+            expect(coverage_report.files.keys).to match_array(['com/example/javademo/User.java'])
+          end
+        end
+      end
+
       context 'when there is a corrupted Cobertura coverage report' do
         before do
           create(:ci_job_artifact, :coverage_with_corrupted_data, job: build, project: build.project)
         end
 
         it 'raises an error' do
-          expect { subject }.to raise_error(Gitlab::Ci::Parsers::Coverage::Cobertura::CoberturaParserError)
+          expect { subject }.to raise_error(Gitlab::Ci::Parsers::Coverage::Cobertura::InvalidLineInformationError)
         end
       end
     end

spec/models/ci/pipeline_spec.rb

@@ -3418,6 +3418,16 @@ RSpec.describe Ci::Pipeline, :mailer, factory_default: :keep do
         ])
       end
 
+      it 'does not execute N+1 queries' do
+        single_build_pipeline = create(:ci_empty_pipeline, status: :created, project: project)
+        single_rspec = create(:ci_build, :success, name: 'rspec', pipeline: single_build_pipeline, project: project)
+        create(:ci_job_artifact, :cobertura, job: single_rspec, project: project)
+
+        control = ActiveRecord::QueryRecorder.new { single_build_pipeline.coverage_reports }
+
+        expect { subject }.not_to exceed_query_limit(control)
+      end
+
       context 'when builds are retried' do
         let!(:build_rspec) { create(:ci_build, :retried, :success, name: 'rspec', pipeline: pipeline, project: project) }
         let!(:build_golang) { create(:ci_build, :retried, :success, name: 'golang', pipeline: pipeline, project: project) }

spec/services/ci/pipelines/create_artifact_service_spec.rb

@@ -7,7 +7,8 @@ RSpec.describe ::Ci::Pipelines::CreateArtifactService do
     subject { described_class.new.execute(pipeline) }
 
     context 'when pipeline has coverage reports' do
-      let(:pipeline) { create(:ci_pipeline, :with_coverage_reports) }
+      let(:project) { create(:project, :repository) }
+      let(:pipeline) { create(:ci_pipeline, :with_coverage_reports, project: project) }
 
       context 'when pipeline is finished' do
         it 'creates a pipeline artifact' do