Extract a class that represents artifacts file path

lib/gitlab/ci/build/artifacts/metadata/entry.rb

 module Gitlab
-  module Ci::Build::Artifacts
-    class Metadata
-      ##
-      # Class that represents an entry (path and metadata) to a file or
-      # directory in GitLab CI Build Artifacts binary file / archive
-      #
-      # This is IO-operations safe class, that does similar job to
-      # Ruby's Pathname but without the risk of accessing filesystem.
-      #
-      # This class is working only with UTF-8 encoded paths.
-      #
-      class Entry
-        attr_reader :path, :entries
-        attr_accessor :name
-
-        def initialize(path, entries)
-          @path = path.dup.force_encoding('UTF-8')
-          @entries = entries
-
-          if path.include?("\0")
-            raise ArgumentError, 'Path contains zero byte character!'
-          end
+  module Ci
+    module Build
+      module Artifacts
+        class Metadata
+          ##
+          # Class that represents an entry (path and metadata) to a file or
+          # directory in GitLab CI Build Artifacts binary file / archive
+          #
+          # This is IO-operations safe class, that does similar job to
+          # Ruby's Pathname but without the risk of accessing filesystem.
+          #
+          # This class is working only with UTF-8 encoded paths.
+          #
+          class Entry
+            attr_reader :entries
+            attr_accessor :name
+
+            def initialize(path, entries)
+              @entries = entries
+              @path = Artifacts::Path.new(path)
+            end
+
+            delegate :empty?, to: :children
+
+            def directory?
+              blank_node? || @path.directory?
+            end
+
+            def file?
+              !directory?
+            end
+
+            def blob
+              return unless file?
+
+              @blob ||= Blob.decorate(::Ci::ArtifactBlob.new(self), nil)
+            end
+
+            def has_parent?
+              nodes > 0
+            end
+
+            def parent
+              return nil unless has_parent?
+              self.class.new(@path.to_s.chomp(basename), @entries)
+            end
+
+            def basename
+              (directory? && !blank_node?) ? name + '/' : name
+            end
+
+            def name
+              @name || @path.name
+            end
+
+            def children
+              return [] unless directory?
+              return @children if @children
+
+              child_pattern = %r{^#{Regexp.escape(@path.to_s)}[^/]+/?$}
+              @children = select_entries { |path| path =~ child_pattern }
+            end
+
+            def directories(opts = {})
+              return [] unless directory?
+              dirs = children.select(&:directory?)
+              return dirs unless has_parent? && opts[:parent]
+
+              dotted_parent = parent
+              dotted_parent.name = '..'
+              dirs.prepend(dotted_parent)
+            end
+
+            def files
+              return [] unless directory?
+              children.select(&:file?)
+            end
+
+            def metadata
+              @entries[@path.to_s] || {}
+            end
+
+            def nodes
+              @path.nodes + (file? ? 1 : 0)
+            end
+
+            def blank_node?
+              @path.to_s.empty? # "" is considered to be './'
+            end
+
+            def exists?
+              blank_node? || @entries.include?(@path.to_s)
+            end
+
+            def total_size
+              descendant_pattern = %r{^#{Regexp.escape(@path.to_s)}}
+              entries.sum do |path, entry|
+                (entry[:size] if path =~ descendant_pattern).to_i
+              end
+            end
+
+            def path
+              @path.to_s
+            end
+
+            def to_s
+              @path.to_s
+            end
+
+            def ==(other)
+              path == other.path && @entries == other.entries
+            end
+
+            def inspect
+              "#{self.class.name}: #{self.to_s}"
+            end
 
-          unless path.valid_encoding?
-            raise ArgumentError, 'Path contains non-UTF-8 byte sequence!'
+            private
+
+            def select_entries
+              selected = @entries.select { |path, _metadata| yield path }
+              selected.map { |path, _metadata| self.class.new(path, @entries) }
+            end
           end
         end
-
-        delegate :empty?, to: :children
-
-        def directory?
-          blank_node? || @path.end_with?('/')
-        end
-
-        def file?
-          !directory?
-        end
-
-        def blob
-          return unless file?
-
-          @blob ||= Blob.decorate(::Ci::ArtifactBlob.new(self), nil)
-        end
-
-        def has_parent?
-          nodes > 0
-        end
-
-        def parent
-          return nil unless has_parent?
-          self.class.new(@path.chomp(basename), @entries)
-        end
-
-        def basename
-          (directory? && !blank_node?) ? name + '/' : name
-        end
-
-        def name
-          @name || @path.split('/').last.to_s
-        end
-
-        def children
-          return [] unless directory?
-          return @children if @children
-
-          child_pattern = %r{^#{Regexp.escape(@path)}[^/]+/?$}
-          @children = select_entries { |path| path =~ child_pattern }
-        end
-
-        def directories(opts = {})
-          return [] unless directory?
-          dirs = children.select(&:directory?)
-          return dirs unless has_parent? && opts[:parent]
-
-          dotted_parent = parent
-          dotted_parent.name = '..'
-          dirs.prepend(dotted_parent)
-        end
-
-        def files
-          return [] unless directory?
-          children.select(&:file?)
-        end
-
-        def metadata
-          @entries[@path] || {}
-        end
-
-        def nodes
-          @path.count('/') + (file? ? 1 : 0)
-        end
-
-        def blank_node?
-          @path.empty? # "" is considered to be './'
-        end
-
-        def exists?
-          blank_node? || @entries.include?(@path)
-        end
-
-        def total_size
-          descendant_pattern = %r{^#{Regexp.escape(@path)}}
-          entries.sum do |path, entry|
-            (entry[:size] if path =~ descendant_pattern).to_i
-          end
-        end
-
-        def to_s
-          @path
-        end
-
-        def ==(other)
-          @path == other.path && @entries == other.entries
-        end
-
-        def inspect
-          "#{self.class.name}: #{@path}"
-        end
-
-        private
-
-        def select_entries
-          selected = @entries.select { |path, _metadata| yield path }
-          selected.map { |path, _metadata| self.class.new(path, @entries) }
-        end
       end
     end
   end

lib/gitlab/ci/build/artifacts/path.rb

+module Gitlab
+  module Ci
+    module Build
+      module Artifacts
+        class Path
+          def initialize(path)
+            @path = path.dup.force_encoding('UTF-8')
+          end
+
+          def valid?
+            nonzero? && utf8?
+          end
+
+          def directory?
+            @path.end_with?('/')
+          end
+
+          def name
+            @path.split('/').last.to_s
+          end
+
+          def nodes
+            @path.count('/')
+          end
+
+          def to_s
+            @path.tap do |path|
+              unless nonzero?
+                raise ArgumentError, 'Path contains zero byte character!'
+              end
+
+              unless utf8?
+                raise ArgumentError, 'Path contains non-UTF-8 byte sequence!'
+              end
+            end
+          end
+
+          private
+
+          def nonzero?
+            @path.exclude?("\0")
+          end
+
+          def utf8?
+            @path.valid_encoding?
+          end
+        end
+      end
+    end
+  end
+end

spec/lib/gitlab/ci/build/artifacts/path_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Ci::Build::Artifacts::Path do
+  describe '#valid?' do
+    context 'when path contains a zero character' do
+      it 'is not valid' do
+        expect(described_class.new("something/\255")).not_to be_valid
+      end
+    end
+
+    context 'when path is not utf8 string' do
+      it 'is not valid' do
+        expect(described_class.new("something/\0")).not_to be_valid
+      end
+    end
+
+    context 'when path is valid' do
+      it 'is valid' do
+        expect(described_class.new("some/file/path")).to be_valid
+      end
+    end
+  end
+
+  describe '#directory?' do
+    context 'when path ends with a directory indicator' do
+      it 'is a directory' do
+        expect(described_class.new("some/file/dir/")).to be_directory
+      end
+    end
+
+    context 'when path does not end with a directory indicator' do
+      it 'is not a directory' do
+        expect(described_class.new("some/file")).not_to be_directory
+      end
+    end
+  end
+
+  describe '#name' do
+    it 'returns a base name' do
+      expect(described_class.new("some/file").name).to eq 'file'
+    end
+  end
+
+  describe '#nodes' do
+    it 'returns number of path nodes' do
+      expect(described_class.new("some/dir/file").nodes).to eq 2
+    end
+  end
+
+  describe '#to_s' do
+    context 'when path is valid' do
+      it 'returns a string representation of a path' do
+        expect(described_class.new('some/path').to_s).to eq 'some/path'
+      end
+    end
+
+    context 'when path is invalid' do
+      it 'raises an error' do
+        expect { described_class.new("invalid/\0").to_s }
+          .to raise_error ArgumentError
+      end
+    end
+  end
+end