chore: add rubocop pre-commit hook and fix all offenses

.pre-commit-config.yaml

@@ -30,6 +30,13 @@ repos:
       - id: check-added-large-files
       - id: mixed-line-ending
 
+  - repo: https://github.com/rubocop/rubocop
+    rev: v1.86.2
+    hooks:
+      - id: rubocop
+        language_version: 3.4.7
+        args: ['--autocorrect', '--force-exclusion']
+
   - repo: https://github.com/woodruffw/zizmor-pre-commit
     rev: v1.25.2
     hooks:

.rubocop.yml

@@ -0,0 +1,30 @@
+AllCops:
+  NewCops: enable
+  SuggestExtensions: false
+  TargetRubyVersion: 3.4
+
+# Dockerfile_spec.rb filenames are intentional — they mirror the Dockerfile being tested
+Naming/FileName:
+  Exclude:
+    - 'spec/**/*'
+
+# Not required for a test-only project
+Style/FrozenStringLiteralComment:
+  Enabled: false
+
+# Spec helpers contain necessarily complex cleanup logic
+Metrics/MethodLength:
+  Exclude:
+    - 'spec/**/*'
+
+Metrics/AbcSize:
+  Exclude:
+    - 'spec/**/*'
+
+Metrics/CyclomaticComplexity:
+  Exclude:
+    - 'spec/**/*'
+
+Metrics/PerceivedComplexity:
+  Exclude:
+    - 'spec/**/*'

.ruby-version

@@ -0,0 +1 @@
+3.4.9

Gemfile

@@ -1,4 +1,4 @@
-source "https://rubygems.org"
+source 'https://rubygems.org'
 
 gem 'docker-api', '~> 2.4'
 gem 'rake', '~> 13.4'

Rakefile

@@ -4,24 +4,25 @@ require 'rspec/core/rake_task'
 # Enable Docker BuildKit for faster builds with better caching
 ENV['DOCKER_BUILDKIT'] = '1'
 
-task :spec    => 'spec:all'
-task :default => :spec
+task spec: 'spec:all'
+task default: :spec
 
 namespace :spec do
   targets = []
   Dir.glob('./spec/*').each do |dir|
     next unless File.directory?(dir)
+
     target = File.basename(dir)
-    target = "_#{target}" if target == "default"
+    target = "_#{target}" if target == 'default'
     targets << target
   end
 
   # Use multitask for parallel execution
-  multitask :all     => targets
-  task :default => :all
+  multitask all: targets
+  task default: :all
 
   targets.each do |target|
-    original_target = target == "_default" ? target[1..-1] : target
+    original_target = target == '_default' ? target[1..] : target
     desc "Run serverspec tests to #{original_target}"
     task target.to_sym do
       # Run RSpec in a separate process with environment variable set

spec/22/Dockerfile_spec.rb

@@ -3,21 +3,20 @@
 require 'node_tests'
 require 'npm_tests'
 
-tag = ENV['TARGET_HOST']
+tag = ENV.fetch('TARGET_HOST', nil)
 
-describe "#{tag}" do
+describe tag.to_s do
   include Helpers
 
   before(:all) do
     create_image(tag)
   end
 
-  test_node("22.22.0")
+  test_node('22.22.0')
 
   test_npm
 
   after(:all) do
     delete_image
   end
-
 end

spec/24/Dockerfile_spec.rb

@@ -3,21 +3,20 @@
 require 'node_tests'
 require 'npm_tests'
 
-tag = ENV['TARGET_HOST']
+tag = ENV.fetch('TARGET_HOST', nil)
 
-describe "#{tag}" do
+describe tag.to_s do
   include Helpers
 
   before(:all) do
     create_image(tag)
   end
 
-  test_node("24.13.0")
+  test_node('24.13.0')
 
   test_npm
 
   after(:all) do
     delete_image
   end
-
 end

spec/node_tests.rb

@@ -3,6 +3,6 @@
 def test_node(version)
   describe command('node -v') do
     its(:exit_status) { should eq 0 }
-    its(:stdout) { should match /#{version}/ }
+    its(:stdout) { should match(/#{version}/) }
   end
 end

spec/npm_tests.rb

@@ -13,7 +13,7 @@ def test_npm
     its(:exit_status) { should eq 0 }
   end
 
-  describe command("echo \'{\"foo\":\"bar\"}\' | json foo") do
-    its(:stdout) { should match /bar/ }
+  describe command("echo '{\"foo\":\"bar\"}' | json foo") do
+    its(:stdout) { should match(/bar/) }
   end
 end

spec/spec_helper.rb

@@ -1,6 +1,6 @@
 module Helpers
   def create_image(version)
-    puts "Building image..."
+    puts 'Building image...'
 
     begin
       @image = Docker::Image.build_from_dir("#{version}/")
@@ -9,44 +9,44 @@ def create_image(version)
       raise
     end
 
-    set :os, :family => 'debian'
+    set :os, family: 'debian'
     set :backend, :docker
     set :docker_image, @image.id
 
-    puts "Running tests..."
+    puts 'Running tests...'
   end
 
   def delete_image
     return unless @image
 
-    puts "Deleting image..."
+    puts 'Deleting image...'
 
     # Remove specinfra's Docker backend finalizer before we clean up containers.
     # Without this, the finalizer fires at process exit and tries to stop/delete
     # containers we've already removed here, producing "Exception in finalizer" warnings.
     begin
       ObjectSpace.undefine_finalizer(Specinfra.backend)
-    rescue => e
+    rescue StandardError => e
       puts "Warning: Could not undefine specinfra finalizer: #{e.message}"
     end
 
     # Stop and remove only containers created from this image
     begin
-      Docker::Container.all(:all => true).each do |container|
+      Docker::Container.all(all: true).each do |container|
         container_image = container.info['Image']
         container_image_id = container.info['ImageID']
 
         # Match image IDs - container IDs may have sha256: prefix and be full hashes
         # while @image.id is the short ID
-        if container_image&.include?(@image.id) || container_image_id&.include?(@image.id)
-          begin
-            container.stop unless container.info['State'] == 'exited'
-            container.delete(:force => true)
-          rescue Docker::Error::NotModifiedError
-            # Container already stopped, ignore
-          rescue Docker::Error::DockerError => e
-            puts "Warning: Failed to cleanup container #{container.id[0..11]}: #{e.message}"
-          end
+        next unless container_image&.include?(@image.id) || container_image_id&.include?(@image.id)
+
+        begin
+          container.stop unless container.info['State'] == 'exited'
+          container.delete(force: true)
+        rescue Docker::Error::NotModifiedError
+          # Container already stopped, ignore
+        rescue Docker::Error::DockerError => e
+          puts "Warning: Failed to cleanup container #{container.id[0..11]}: #{e.message}"
         end
       end
     rescue Docker::Error::DockerError => e
@@ -55,10 +55,10 @@ def delete_image
 
     # Always attempt to remove the image, even if container cleanup failed
     begin
-      @image.remove(:force => true)
-      puts "Image removed successfully"
+      @image.remove(force: true)
+      puts 'Image removed successfully'
     rescue Docker::Error::NotFoundError
-      puts "Image already removed"
+      puts 'Image already removed'
     rescue Docker::Error::DockerError => e
       puts "Warning: Failed to remove image: #{e.message}"
     end