Issue #326 - supporting upgrade files and version

.rubocop.yml

@@ -31,5 +31,7 @@ Style/MultilineBlockChain:
   Enabled: false
 Layout/MultilineOperationIndentation:
   Enabled: false
+Security/Eval:
+  Enabled: false
 Naming/UncommunicativeMethodParamName:
   MinNameLength: 1

lib/zold/upgrades.rb

@@ -32,7 +32,7 @@ def initialize(version, directory, log: Log::Verbose.new)
     end
 
     def run
-      Dir.glob("#{@directory}/*.rb").select { |f| f =~ /^(\d+)\.rb$/ }.sort.each do |script|
+      Dir.glob("#{@directory}/*.rb").select { |f| f =~ /\d\.\d\.\d\.rb/ }.sort.each do |script|
         @version.apply(script)
       end
     end

lib/zold/version_file.rb

@@ -31,11 +31,28 @@ def initialize(path, log: Log::Verbose.new)
       @log = log
     end
 
-    # @todo #285:30min Replace this stub with functionality.
-    #  We need to run the script (`yield`) if the version of
-    #  the script is between the saved version and the current one.
-    def apply(version)
-      @log.info("Version #{version} doesn't need to be applied.")
+    def apply(script)
+      version = extract_version_from_script_name(script)
+      return unless ::Gem::Version.new(version) > current_version
+      code = File.read(script)
+      eval(code)
+    end
+
+    def extract_version_from_script_name(file_name)
+      file_name.scan(/\d\.\d\.\d/).last
+    end
+
+    def current_version
+      return ::Gem::Version.new('0.0.0') unless File.exist?(version_file)
+      @current_version ||= ::Gem::Version.new(current_version_from_version_file)
+    end
+
+    def current_version_from_version_file
+      File.read(version_file).strip
+    end
+
+    def version_file
+      File.join(@path, 'version')
     end
   end
 end

test/test_upgrades.rb

@@ -30,10 +30,7 @@
 # Copyright:: Copyright (c) 2018 Yegor Bugayenko
 # License:: MIT
 class TestUpgrades < Minitest::Test
-  # @todo #327:30min Uncomment, when you're ready to work on upgrade manager's
-  #  test case of absent version file. Start with running the test first.
   def test_no_version_file_is_ok
-    skip
     Dir.mktmpdir do |dir|
       script_version = '0.0.1'
       create_upgrade_file(dir, script_version)
@@ -43,17 +40,13 @@ def test_no_version_file_is_ok
     end
   end
 
-  # @todo #327:30min Uncomment, when you're ready to work on upgrade manager's
-  #  test case of running only pending upgrade scripts (i.e. the scripts with
-  #  versions greater than those in the version file).
   def test_pending_scripts_run
-    skip
     Dir.mktmpdir do |dir|
       %w[1 2].each do |script_version|
-        create_upgrade_file(dir, script_version)
+        create_upgrade_file(dir, "0.0.#{script_version}")
       end
-      create_version_file(dir, '1')
-      assert_output(/#{expected_upgrade_script_output('2')}/) do
+      create_version_file(dir, '0.0.1')
+      assert_output(/#{expected_upgrade_script_output('0.0.2')}/) do
         run_upgrades(dir)
       end
     end
@@ -62,13 +55,13 @@ def test_pending_scripts_run
   def test_already_ran_scripts_dont_run
     Dir.mktmpdir do |dir|
       %w[1 2].each do |script_version|
-        create_upgrade_file(dir, script_version)
+        create_upgrade_file(dir, "0.0.#{script_version}")
       end
-      create_version_file(dir, '1')
+      create_version_file(dir, '0.0.1')
       out, _err = capture_io do
         run_upgrades(dir)
       end
-      refute_match(/#{expected_upgrade_script_output('1')}/, out)
+      refute_match(/#{expected_upgrade_script_output('0.0.1')}/, out)
     end
   end
 
@@ -79,7 +72,7 @@ def run_upgrades(dir)
   end
 
   def version_file(dir)
-    Zold::VersionFile.new(File.join(dir, 'version'))
+    Zold::VersionFile.new(dir)
   end
 
   def create_version_file(dir, version)