Add Rubocop and get Rubocop passing

This commit adds Rubocop and makes a number of changes to address open lints.

In addition it:

1. Sets the minimum Ruby version to 2.6, removing 2.5 and jruby-9.2 from the CI matrix.
2. Adds Ruby 3.1, jruby-9.3, ruby-head, and jruby-head to the CI matrix
3. Adds missing specs for the client method on Dalli::Elasticache
4. Adds a linting GitHub action

.github/workflows/lint.yml

@@ -0,0 +1,17 @@
+name: Lint
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    name: Lint - Ruby 2.6
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Ruby 2.6
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 2.6
+        bundler-cache: true # 'bundle install' and cache
+    - name: Run Rubocop
+      run: bundle exec rubocop

.github/workflows/tests.yml

@@ -5,11 +5,12 @@ on: [push, pull_request]
 jobs:
   test:
     runs-on: ubuntu-latest
-
     strategy:
+      fail-fast: false
       matrix:
-        ruby-version: [2.5, 2.6, 2.7, '3.0', jruby-9.2, jruby-9.3]
+        ruby-version: [2.6, 2.7, '3.0', 3.1, jruby-9.3, ruby-head, jruby-head]
 
+    name: Specs - Ruby ${{ matrix.ruby-version }}
     steps:
     - uses: actions/checkout@v2
     - name: Set up Ruby ${{ matrix.ruby-version }}

.gitignore

@@ -2,6 +2,7 @@
 *.rbc
 .bundle
 .config
+.ruby-version
 coverage
 InstalledFiles
 lib/bundler/man

.rubocop.yml

@@ -0,0 +1,30 @@
+require:
+  - rubocop-performance
+  - rubocop-rake
+  - rubocop-rspec
+
+AllCops:
+  NewCops: enable
+  TargetRubyVersion: 2.6
+
+Metrics/BlockLength:
+  Max: 50
+  Exclude:
+    - 'spec/**/*'
+
+Naming/FileName:
+  Exclude:
+    - 'lib/dalli-elasticache.rb'
+
+Style/Documentation:
+  Exclude:
+    - 'spec/**/*'
+
+RSpec/ExampleLength:
+  Enabled: false
+
+RSpec/MultipleExpectations:
+  Enabled: false
+
+RSpec/MultipleMemoizedHelpers:
+  Enabled: false

Gemfile

@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 gemspec

Rakefile

@@ -1,8 +1,10 @@
-require "rubygems"
-require "bundler/setup"
-require "bundler/gem_tasks"
-require "rspec/core/rake_task"
+# frozen_string_literal: true
+
+require 'rubygems'
+require 'bundler/setup'
+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:test)
 
-task :default => :test
+task default: :test

dalli-elasticache.gemspec

@@ -1,34 +1,37 @@
-# -*- encoding: utf-8 -*-
-lib = File.expand_path('../lib/', __FILE__)
-$:.unshift lib unless $:.include?(lib)
+# frozen_string_literal: true
 
-require 'dalli/elasticache/version'
+require_relative './lib/dalli/elasticache/version'
 
 Gem::Specification.new do |s|
   s.name     = 'dalli-elasticache'
   s.version  = Dalli::ElastiCache::VERSION
   s.licenses = ['MIT']
-  
+
   s.summary     = "Configure Dalli clients with ElastiCache's AutoDiscovery"
-  s.description = <<-EOS
+  s.description = <<-DESC
     This gem provides an interface for fetching cluster information from an AWS
     ElastiCache AutoDiscovery server and configuring a Dalli client to connect
     to all nodes in the cache cluster.
-  EOS
-  
-  s.authors     = ["Aaron Suggs", "Zach Millman"]
-  s.email       = ["[email protected]", "[email protected]"]
+  DESC
+
+  s.authors     = ['Aaron Suggs', 'Zach Millman', 'Peter M. Goldstein']
+  s.email       = ['[email protected]', '[email protected]', '[email protected]']
   s.homepage    = 'http://github.com/ktheory/dalli-elasticache'
-  
-  s.files         = Dir.glob("{bin,lib}/**/*") + %w(README.md Rakefile)
-  s.rdoc_options  = ["--charset=UTF-8"]
-  s.require_paths = ["lib"]
-  s.test_files    = Dir.glob("{test,spec}/**/*")
-  
-  s.required_ruby_version     = '>= 1.9.2' # Maybe less?
+
+  s.files         = Dir.glob('{bin,lib}/**/*') + %w[README.md Rakefile]
+  s.rdoc_options  = ['--charset=UTF-8']
+  s.require_paths = ['lib']
+  s.test_files    = Dir.glob('{test,spec}/**/*')
+
+  s.required_ruby_version     = '>= 2.6.0'
   s.required_rubygems_version = '>= 1.3.5'
-  
+
   s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec'
-  s.add_dependency 'dalli', ">= 1.0.0" # ??
+  s.add_development_dependency 'rubocop'
+  s.add_development_dependency 'rubocop-performance'
+  s.add_development_dependency 'rubocop-rake'
+  s.add_development_dependency 'rubocop-rspec'
+  s.add_dependency 'dalli', '>= 2.0.0'
+  s.metadata['rubygems_mfa_required'] = 'true'
 end

lib/dalli-elasticache.rb

@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 # Support default bundler require path
 require 'dalli/elasticache'

lib/dalli/elasticache.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'dalli'
 require 'socket'
 require 'dalli/elasticache/version'
@@ -6,42 +8,60 @@
 require 'dalli/elasticache/auto_discovery/stats_response'
 
 module Dalli
+  ##
+  # Dalli::Elasticache provides an interface for providing a configuration
+  # endpoint for a memcached cluster on ElasticCache and retrieving the
+  # list of addresses (IP and port) for the individual nodes of that cluster.
+  #
+  # This allows the caller to pass that server list to Dalli, which then
+  # distributes cached items consistently over the nodes.
+  ##
   class ElastiCache
     attr_reader :endpoint, :options
-
-    def initialize(config_endpoint, options={})
+
+    ##
+    # Creates a new Dalli::ElasticCache instance.
+    #
+    # config_endpoint - a String containing the host and (optionally) port of the
+    # configuration endpoint for the cluster.  If not specified the port will
+    # default to 11211.  The host must be either a DNS name or an IPv4 address.  IPv6
+    # addresses are not handled at this time.
+    # dalli_options - a set of options passed to the Dalli::Client that is returned
+    # by the client method.  Otherwise unused.
+    ##
+    def initialize(config_endpoint, dalli_options = {})
       @endpoint = Dalli::Elasticache::AutoDiscovery::Endpoint.new(config_endpoint)
-      @options = options
+      @options = dalli_options
     end
-    
+
     # Dalli::Client configured to connect to the cluster's nodes
     def client
       Dalli::Client.new(servers, options)
     end
-    
+
     # The number of times the cluster configuration has been changed
     #
     # Returns an integer
     def version
       endpoint.config.version
     end
-    
+
     # The cache engine version of the cluster
     def engine_version
       endpoint.engine_version
     end
-    
+
     # List of cluster server nodes with ip addresses and ports
     # Always use host name instead of private elasticache IPs as internal IPs can change after a node is rebooted
     def servers
-      endpoint.config.nodes.map{ |h| "#{h[:host]}:#{h[:port]}" }
+      endpoint.config.nodes.map { |h| "#{h[:host]}:#{h[:port]}" }
     end
-    
+
     # Clear all cached data from the cluster endpoint
     def refresh
       config_endpoint = "#{endpoint.host}:#{endpoint.port}"
       @endpoint = Dalli::Elasticache::AutoDiscovery::Endpoint.new(config_endpoint)
-      
+
       self
     end
   end

lib/dalli/elasticache/auto_discovery/config_response.rb

@@ -1,48 +1,46 @@
+# frozen_string_literal: true
+
 module Dalli
   module Elasticache
     module AutoDiscovery
-
       # This class wraps the raw ASCII response from an Auto Discovery endpoint
       # and provides methods for extracting data from that response.
       #
       # http://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/AutoDiscovery.AddingToYourClientLibrary.html
-
       class ConfigResponse
-
         # The raw response text
         attr_reader :text
-    
+
         # Matches the version line of the response
-        VERSION_REGEX = /^(\d+)$/
-    
+        VERSION_REGEX = /^(\d+)$/.freeze
+
         # Matches strings like "my-cluster.001.cache.aws.com|10.154.182.29|11211"
-        NODE_REGEX = /(([-.a-zA-Z0-9]+)\|(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b)\|(\d+))/
-        NODE_LIST_REGEX = /^(#{NODE_REGEX}\s*)+$/
-    
+        NODE_REGEX = /(([-.a-zA-Z0-9]+)\|(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b)\|(\d+))/.freeze
+        NODE_LIST_REGEX = /^(#{NODE_REGEX}\s*)+$/.freeze
+
         def initialize(response_text)
           @text = response_text.to_s
         end
-    
+
         # The number of times the configuration has been changed
         #
         # Returns an integer
         def version
           VERSION_REGEX.match(@text)[1].to_i
         end
-    
+
         # Node hosts, ip addresses, and ports
         #
         # Returns an Array of Hashes with values for :host, :ip and :port
         def nodes
           NODE_LIST_REGEX.match(@text).to_s.scan(NODE_REGEX).map do |match|
             {
-              :host => match[1],
-              :ip   => match[2],
-              :port => match[3].to_i
+              host: match[1],
+              ip: match[2],
+              port: match[3].to_i
             }
           end
         end
-
       end
     end
   end