Use SAX parser for cobertura coverage reports

- Remove FF use_cobertura_sax_parser
- Clean leagcy DOM parser

Changelog: changed

config/feature_flags/development/use_cobertura_sax_parser.yml

----
-name: use_cobertura_sax_parser
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/79866
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/352579
-milestone: '14.9'
-type: development
-group: group::memory
-default_enabled: false

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

@@ -9,11 +9,7 @@ module Gitlab
           InvalidLineInformationError = Class.new(Gitlab::Ci::Parsers::ParserError)
 
           def parse!(xml_data, coverage_report, project_path: nil, worktree_paths: nil)
-            if Feature.enabled?(:use_cobertura_sax_parser, default_enabled: :yaml)
-              Nokogiri::XML::SAX::Parser.new(SaxDocument.new(coverage_report, project_path, worktree_paths)).parse(xml_data)
-            else
-              DomParser.new.parse(xml_data, coverage_report, project_path, worktree_paths)
-            end
+            Nokogiri::XML::SAX::Parser.new(SaxDocument.new(coverage_report, project_path, worktree_paths)).parse(xml_data)
           end
         end
       end

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

-# frozen_string_literal: true
-
-module Gitlab
-  module Ci
-    module Parsers
-      module Coverage
-        class DomParser
-          GO_SOURCE_PATTERN = '/usr/local/go/src'
-          MAX_SOURCES = 100
-
-          def parse(xml_data, coverage_report, project_path, worktree_paths)
-            root = Hash.from_xml(xml_data)
-
-            context = {
-              project_path: project_path,
-              paths: worktree_paths&.to_set,
-              sources: []
-            }
-
-            parse_all(root, coverage_report, context)
-          rescue Nokogiri::XML::SyntaxError
-            raise Cobertura::InvalidXMLError, "XML parsing failed"
-          end
-
-          private
-
-          def parse_all(root, coverage_report, context)
-            return unless root.present?
-
-            root.each do |key, value|
-              parse_node(key, value, coverage_report, context)
-            end
-          end
-
-          def parse_node(key, value, coverage_report, context)
-            if key == 'sources' && value && value['source'].present?
-              parse_sources(value['source'], context)
-            elsif key == 'package'
-              Array.wrap(value).each do |item|
-                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, context)
-            elsif value.is_a?(Array)
-              value.each do |item|
-                parse_all(item, coverage_report, context)
-              end
-            end
-          end
-
-          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
-
-            filename
-          end
-
-          def parse_lines(lines)
-            line_array = Array.wrap(lines["line"])
-
-            line_array.map do |line|
-              # Using `Integer()` here to raise exception on invalid values
-              [Integer(line["number"]), Integer(line["hits"])]
-            end
-          rescue StandardError
-            raise Cobertura::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
-    end
-  end
-end

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

@@ -10,35 +10,15 @@ RSpec.describe Gitlab::Ci::Parsers::Coverage::Cobertura do
 
   subject(:parse_report) { described_class.new.parse!(xml_data, coverage_report, project_path: project_path, worktree_paths: paths) }
 
-  context 'when use_cobertura_sax_parser feature flag is enabled' do
-    before do
-      stub_feature_flags(use_cobertura_sax_parser: true)
-
-      allow_next_instance_of(Nokogiri::XML::SAX::Parser) do |document|
-        allow(document).to receive(:parse)
-      end
-    end
-
-    it 'uses Sax parser' do
-      expect(Gitlab::Ci::Parsers::Coverage::SaxDocument).to receive(:new)
-
-      parse_report
+  before do
+    allow_next_instance_of(Nokogiri::XML::SAX::Parser) do |document|
+      allow(document).to receive(:parse)
     end
   end
 
-  context 'when use_cobertura_sax_parser feature flag is disabled' do
-    before do
-      stub_feature_flags(use_cobertura_sax_parser: false)
+  it 'uses Sax parser' do
+    expect(Gitlab::Ci::Parsers::Coverage::SaxDocument).to receive(:new)
 
-      allow_next_instance_of(Gitlab::Ci::Parsers::Coverage::DomParser) do |parser|
-        allow(parser).to receive(:parse)
-      end
-    end
-
-    it 'uses Dom parser' do
-      expect(Gitlab::Ci::Parsers::Coverage::DomParser).to receive(:new)
-
-      parse_report
-    end
+    parse_report
   end
 end

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

-# frozen_string_literal: true
-
-require 'fast_spec_helper'
-require 'support/shared_examples/lib/gitlab/ci/parsers/coverage/cobertura_xml_shared_examples'
-
-RSpec.describe Gitlab::Ci::Parsers::Coverage::DomParser do
-  subject(:parse_report) { described_class.new.parse(cobertura, coverage_report, project_path, paths) }
-
-  include_examples 'parse cobertura xml'
-end