Add Packages::Debian::ExtractMetadataService

app/services/packages/debian/extract_metadata_service.rb

+# frozen_string_literal: true
+
+module Packages
+  module Debian
+    class ExtractMetadataService
+      include Gitlab::Utils::StrongMemoize
+
+      ExtractionError = Class.new(StandardError)
+
+      def initialize(package_file)
+        @package_file = package_file
+      end
+
+      def execute
+        raise ExtractionError.new('invalid package file') unless valid_package_file?
+
+        extract_metadata
+      end
+
+      private
+
+      attr_reader :package_file
+
+      def valid_package_file?
+        package_file &&
+          package_file.package&.debian? &&
+          package_file.file.size > 0 # rubocop:disable Style/ZeroLengthPredicate
+      end
+
+      def file_type_basic
+        %i[dsc deb udeb buildinfo changes].each do |format|
+          return format if package_file.file_name.end_with?(".#{format}")
+        end
+
+        nil
+      end
+
+      def file_type_source
+        # https://manpages.debian.org/buster/dpkg-dev/dpkg-source.1.en.html
+        %i[gzip bzip2 lzma xz].each do |format|
+          return :source if package_file.file_name.end_with?(".tar.#{format}")
+        end
+
+        nil
+      end
+
+      def file_type
+        strong_memoize(:file_type) do
+          file_type_basic || file_type_source || :unknown
+        end
+      end
+
+      def file_type_debian?
+        file_type == :deb || file_type == :udeb
+      end
+
+      def file_type_meta?
+        file_type == :dsc || file_type == :buildinfo || file_type == :changes
+      end
+
+      def extracted_fields
+        if file_type_debian?
+          package_file.file.use_file do |file_path|
+            ::Packages::Debian::ExtractDebMetadataService.new(file_path).execute
+          end
+        elsif file_type_meta?
+          package_file.file.use_file do |file_path|
+            ::Packages::Debian::ParseDebian822Service.new(File.read(file_path)).execute.each_value.first
+          end
+        end
+      end
+
+      def extract_metadata
+        fields = extracted_fields
+        architecture = fields.delete(:Architecture) if file_type_debian?
+
+        {
+          file_type: file_type,
+          architecture: architecture,
+          fields: fields
+        }
+      end
+    end
+  end
+end

spec/services/packages/debian/extract_metadata_service_spec.rb

+# frozen_string_literal: true
+require 'spec_helper'
+
+RSpec.describe Packages::Debian::ExtractMetadataService do
+  let(:service) { described_class.new(package_file) }
+
+  subject { service.execute }
+
+  RSpec.shared_context 'Debian ExtractMetadata Service' do |trait|
+    let(:package_file) { create(:debian_package_file, trait) }
+  end
+
+  RSpec.shared_examples 'Test Debian ExtractMetadata Service' do |expected_file_type, expected_architecture, expected_fields|
+    it "returns file_type #{expected_file_type.inspect}" do
+      expect(subject[:file_type]).to eq(expected_file_type)
+    end
+
+    it "returns architecture #{expected_architecture.inspect}" do
+      expect(subject[:architecture]).to eq(expected_architecture)
+    end
+
+    it "returns fields #{expected_fields.nil? ? '' : 'including '}#{expected_fields.inspect}" do
+      if expected_fields.nil?
+        expect(subject[:fields]).to be_nil
+      else
+        expect(subject[:fields]).to include(**expected_fields)
+      end
+    end
+  end
+
+  using RSpec::Parameterized::TableSyntax
+
+  where(:case_name, :trait, :expected_file_type, :expected_architecture, :expected_fields) do
+    'with invalid'    | :invalid   | :unknown   | nil     | nil
+    'with source'     | :source    | :source    | nil     | nil
+    'with dsc'        | :dsc       | :dsc       | nil     | { 'Binary': 'sample-dev, libsample0, sample-udeb' }
+    'with deb'        | :deb       | :deb       | 'amd64' | { 'Multi-Arch': 'same' }
+    'with udeb'       | :udeb      | :udeb      | 'amd64' | { 'Package': 'sample-udeb' }
+    'with buildinfo'  | :buildinfo | :buildinfo | nil     | { 'Architecture': 'amd64 source', 'Build-Architecture': 'amd64' }
+    'with changes'    | :changes   | :changes   | nil     | { 'Architecture': 'source amd64', 'Binary': 'libsample0 sample-dev sample-udeb' }
+  end
+
+  with_them do
+    include_context 'Debian ExtractMetadata Service', params[:trait] do
+      it_behaves_like 'Test Debian ExtractMetadata Service',
+        params[:expected_file_type],
+        params[:expected_architecture],
+        params[:expected_fields]
+    end
+  end
+
+  context 'with invalid package file' do
+    let(:package_file) { create(:conan_package_file) }
+
+    it 'raise error' do
+      expect { subject }.to raise_error(described_class::ExtractionError, 'invalid package file')
+    end
+  end
+end