1 files changed, 110 insertions, 0 deletions
diff --git a/lib/gitlab/ci/parsers/coverage/sax_document.rb b/lib/gitlab/ci/parsers/coverage/sax_document.rb
new file mode 100644
index 00000000000..27cce0e3a3b
--- /dev/null
+++ b/lib/gitlab/ci/parsers/coverage/sax_document.rb
@@ -0,0 +1,110 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Parsers
+      module Coverage
+        class SaxDocument < Nokogiri::XML::SAX::Document
+          GO_SOURCE_PATTERN = '/usr/local/go/src'
+          MAX_SOURCES = 100
+
+          def initialize(coverage_report, project_path, worktree_paths)
+            @coverage_report = coverage_report
+            @project_path = project_path
+            @paths = worktree_paths&.to_set
+
+            @matched_filenames = []
+            @parsed_lines = []
+            @sources = []
+          end
+
+          def error(error)
+            raise Cobertura::InvalidXMLError, "XML parsing failed with error: #{error}"
+          end
+
+          def start_element(node_name, attrs = [])
+            return unless node_name
+
+            self.node_name = node_name
+            node_attrs = Hash[attrs]
+
+            if node_name == 'class' && node_attrs["filename"].present?
+              self.filename = determine_filename(node_attrs["filename"])
+              self.matched_filenames << filename if filename
+            elsif node_name == 'line'
+              self.parsed_lines << parse_line(node_attrs)
+            end
+          end
+
+          def characters(node_content)
+            if node_name == 'source'
+              parse_source(node_content)
+            end
+          end
+
+          def end_element(node_name)
+            if node_name == "package"
+              remove_matched_filenames
+            elsif node_name == "class" && filename && parsed_lines.present?
+              coverage_report.add_file(filename, Hash[parsed_lines])
+              self.filename = nil
+              self.parsed_lines = []
+            end
+          end
+
+          private
+
+          attr_accessor :coverage_report, :project_path, :paths, :sources, :node_name, :filename, :parsed_lines, :matched_filenames
+
+          def parse_line(line)
+            [Integer(line["number"]), Integer(line["hits"])]
+          rescue StandardError
+            raise Cobertura::InvalidLineInformationError, "Line information had invalid values"
+          end
+
+          def parse_source(node)
+            return unless project_path && paths && !node.include?(GO_SOURCE_PATTERN)
+
+            source = build_source_path(node)
+            self.sources << source if source.present?
+          end
+
+          def build_source_path(node)
+            # | raw source                  | extracted  |
+            # |-----------------------------|------------|
+            # | /builds/foo/test/SampleLib/ | SampleLib/ |
+            # | /builds/foo/test/something  | something  |
+            # | /builds/foo/test/           | nil        |
+            # | /builds/foo/test            | nil        |
+            node.split("#{project_path}/", 2)[1]
+          end
+
+          def remove_matched_filenames
+            return unless paths
+
+            matched_filenames.each { |f| paths.delete(f) }
+          end
+
+          def determine_filename(filename)
+            return filename unless sources.any?
+
+            full_filename = nil
+
+            sources.each_with_index do |source, index|
+              break if index >= MAX_SOURCES
+              break if full_filename = check_source(source, filename)
+            end
+
+            full_filename
+          end
+
+          def check_source(source, filename)
+            full_path = File.join(source, filename)
+
+            return full_path if paths.include?(full_path)
+          end
+        end
+      end
+    end
+  end
+end