Rubocop it up

.rubocop.yml

@@ -0,0 +1,16 @@
+inherit_gem:
+  rubocop-standard:
+    - config/default.yml
+
+Style/StringLiterals:
+  Enabled: true
+  EnforcedStyle: single_quotes
+
+RequireParentheses:
+  Enabled: true
+
+Naming/FileName:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false

.travis.yml

@@ -5,5 +5,13 @@ rvm:
   - 2.5
   - 2.6
 
+git:
+  depth: 10
+
 sudo: false
 cache: bundler
+
+matrix:
+  include:
+    - script: bundle exec rake rubocop
+      rvm: 2.6.0

Gemfile

@@ -1,5 +1,7 @@
-source "https://rubygems.org"
+# frozen_string_literal: true
+
+source 'https://rubygems.org'
 
 gemspec
 
-gem "jekyll", ENV["JEKYLL_VERSION"] if ENV["JEKYLL_VERSION"]
+gem 'jekyll', ENV['JEKYLL_VERSION'] if ENV['JEKYLL_VERSION']

Rakefile

@@ -1,8 +1,14 @@
+# frozen_string_literal: true
+
 require 'bundler'
 Bundler::GemHelper.install_tasks
 
 require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
 
-task :default => :spec
+task default: :spec
+
+require 'rubocop/rake_task'
+
+RuboCop::RakeTask.new(:rubocop)

jekyll-last-modified-at.gemspec

@@ -1,17 +1,22 @@
-require File.expand_path('../lib/jekyll-last-modified-at/version.rb', __FILE__)
+# frozen_string_literal: true
+
+require File.expand_path('lib/jekyll-last-modified-at/version.rb', __dir__)
 Gem::Specification.new do |s|
-  s.name                  = "jekyll-last-modified-at"
+  s.name                  = 'jekyll-last-modified-at'
   s.version               = Jekyll::LastModifiedAt::VERSION
-  s.summary               = "A liquid tag for Jekyll to indicate the last time a file was modified."
-  s.authors               = "Garen J. Torikian"
-  s.homepage              = "https://github.com/gjtorikian/jekyll-last-modified-at"
-  s.license               = "MIT"
-  s.files                 = Dir["lib/**/*.rb"]
+  s.summary               = 'A liquid tag for Jekyll to indicate the last time a file was modified.'
+  s.authors               = 'Garen J. Torikian'
+  s.homepage              = 'https://github.com/gjtorikian/jekyll-last-modified-at'
+  s.license               = 'MIT'
+  s.files                 = Dir['lib/**/*.rb']
 
-  s.add_dependency "jekyll", ">= 3.7", " < 5.0"
-  s.add_dependency "posix-spawn", "~> 0.3.9"
+  s.add_dependency 'jekyll', '>= 3.7', ' < 5.0'
+  s.add_dependency 'posix-spawn', '~> 0.3.9'
 
-  s.add_development_dependency "rspec", "~> 3.4"
-  s.add_development_dependency "rake"
-  s.add_development_dependency "spork"
+  s.add_development_dependency 'rake'
+  s.add_development_dependency 'rspec', '~> 3.4'
+  s.add_development_dependency 'rubocop'
+  s.add_development_dependency 'rubocop-performance'
+  s.add_development_dependency 'rubocop-standard'
+  s.add_development_dependency 'spork'
 end

lib/jekyll-last-modified-at.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 module Jekyll
   module LastModifiedAt
@@ -8,10 +9,7 @@ module LastModifiedAt
     autoload :Hook, 'jekyll-last-modified-at/hook'
     autoload :Git, 'jekyll-last-modified-at/git'
 
-    Tag ; Hook
-
-    PATH_CACHE = {}
-
-    REPO_CACHE = {}
+    PATH_CACHE = {} # rubocop:disable Style/MutableConstant
+    REPO_CACHE = {} # rubocop:disable Style/MutableConstant
   end
 end

lib/jekyll-last-modified-at/determinator.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module LastModifiedAt
     class Determinator
@@ -11,27 +13,27 @@ def initialize(site_source, page_path, opts = {})
 
       def git
         return REPO_CACHE[site_source] unless REPO_CACHE[site_source].nil?
+
         REPO_CACHE[site_source] = Git.new(site_source)
         REPO_CACHE[site_source]
       end
 
       def formatted_last_modified_date
         return PATH_CACHE[page_path] unless PATH_CACHE[page_path].nil?
+
         last_modified = last_modified_at_time.strftime(format)
         PATH_CACHE[page_path] = last_modified
         last_modified
       end
 
       def last_modified_at_time
-        unless File.exists? absolute_path_to_article
-          raise Errno::ENOENT, "#{absolute_path_to_article} does not exist!"
-        end
+        raise Errno::ENOENT, "#{absolute_path_to_article} does not exist!" unless File.exist? absolute_path_to_article
 
         Time.at(last_modified_at_unix.to_i)
       end
 
       def last_modified_at_unix
-        if git.is_git_repo?
+        if git.git_repo?
           last_commit_date = Executor.sh(
             'git',
             '--git-dir',
@@ -44,7 +46,7 @@ def last_modified_at_unix
             relative_path_from_git_dir
           )[/\d+/]
           # last_commit_date can be nil iff the file was not committed.
-          (last_commit_date.nil? || last_commit_date.empty?) ? mtime(absolute_path_to_article) : last_commit_date
+          last_commit_date.nil? || last_commit_date.empty? ? mtime(absolute_path_to_article) : last_commit_date
         else
           mtime(absolute_path_to_article)
         end
@@ -59,7 +61,7 @@ def to_liquid
       end
 
       def format
-        opts['format'] ||= "%d-%b-%y"
+        opts['format'] ||= '%d-%b-%y'
       end
 
       def format=(new_format)
@@ -69,15 +71,16 @@ def format=(new_format)
       private
 
       def absolute_path_to_article
-        @article_file_path ||= Jekyll.sanitized_path(site_source, @page_path)
+        @absolute_path_to_article ||= Jekyll.sanitized_path(site_source, @page_path)
       end
 
       def relative_path_from_git_dir
-        return nil unless git.is_git_repo?
+        return nil unless git.git_repo?
+
         @relative_path_from_git_dir ||= Pathname.new(absolute_path_to_article)
-          .relative_path_from(
-            Pathname.new(File.dirname(git.top_level_directory))
-          ).to_s
+                                                .relative_path_from(
+                                                  Pathname.new(File.dirname(git.top_level_directory))
+                                                ).to_s
       end
 
       def mtime(file)

lib/jekyll-last-modified-at/executor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'posix/spawn'
 
 module Jekyll
@@ -8,23 +10,26 @@ module Executor
       def self.sh(*args)
         r, w = IO.pipe
         e, eo = IO.pipe
-        pid = spawn(*args, {
-          :out => w, r => :close,
-          :err => eo, e => :close
-        })
+        pid = spawn(*args,
+                    :out => w, r => :close,
+                    :err => eo, e => :close)
 
-        if pid > 0
+        if pid.positive?
           w.close
           eo.close
           out = r.read
           err = e.read
           ::Process.waitpid(pid)
-          if out
-            "#{out} #{err}".strip
-          end
+          "#{out} #{err}".strip if out
         end
       ensure
-        [r, w, e, eo].each{ |io| io.close rescue nil }
+        [r, w, e, eo].each do |io|
+          begin
+                                   io.close
+          rescue StandardError
+            nil
+                                 end
+        end
       end
     end
   end

lib/jekyll-last-modified-at/git.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module LastModifiedAt
     class Git
@@ -9,27 +11,28 @@ def initialize(site_source)
       end
 
       def top_level_directory
-        return nil unless is_git_repo?
+        return nil unless git_repo?
+
         @top_level_directory ||= begin
           Dir.chdir(@site_source) do
-            top_level_directory = File.join(Executor.sh("git", "rev-parse", "--show-toplevel"), ".git")
+            @top_level_directory = File.join(Executor.sh('git', 'rev-parse', '--show-toplevel'), '.git')
           end
-        rescue
-          ""
+                                 rescue StandardError
+                                   ''
         end
       end
 
-      def is_git_repo?
+      def git_repo?
         return @is_git_repo unless @is_git_repo.nil?
+
         @is_git_repo = begin
           Dir.chdir(@site_source) do
-            Executor.sh("git", "rev-parse", "--is-inside-work-tree").eql? "true"
+            Executor.sh('git', 'rev-parse', '--is-inside-work-tree').eql? 'true'
           end
-        rescue
-          false
+                       rescue StandardError
+                         false
         end
       end
-
     end
   end
 end

lib/jekyll-last-modified-at/hook.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module LastModifiedAt
     module Hook

lib/jekyll-last-modified-at/tag.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module LastModifiedAt
     class Tag < Liquid::Tag
@@ -8,11 +10,10 @@ def initialize(tag_name, format, tokens)
 
       def render(context)
         site_source = context.registers[:site].source
-        article_file = context.environments.first["page"]["path"]
+        article_file = context.environments.first['page']['path']
 
-        Determinator.new(site_source, article_file, {
-          "format" => @format
-        }).formatted_last_modified_date
+        Determinator.new(site_source, article_file,
+                         'format' => @format).formatted_last_modified_date
       end
     end
   end

lib/jekyll-last-modified-at/version.rb

@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 module Jekyll
   module LastModifiedAt
-    VERSION = "1.1.0"
+    VERSION = '1.1.0'
   end
 end