Add Specs for Yaml files

* Add spec/support folder

* Add YamlSortChecker to check if yaml files are sorted

* Add Diffy as a development dependency

* Add spec file for all yaml config files for sorting

colorls.gemspec

@@ -29,4 +29,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec'
   spec.add_development_dependency 'rubocop'
+  spec.add_development_dependency 'diffy'
 end

spec/support/yaml_sort_checker.rb

@@ -0,0 +1,53 @@
+require 'yaml'
+require 'diffy'
+
+# Check Yaml if Alphabetically sorted
+class YamlSortChecker
+  class NotSortedError < StandardError; end
+
+  def initialize(filename)
+    @yaml = YAML.load_file(filename)
+  end
+
+  def sorted?(type = :key)
+    case type.to_sym
+    when :key   then key_sorted?
+    when :value then value_sorted?
+    end
+
+    true
+  end
+
+  private
+
+  attr_reader :yaml
+
+  def key_sorted?
+    sorted_yaml  = yaml.to_a.sort_by { |content| content[0].downcase }
+
+    different_from_yaml? sorted_yaml
+  end
+
+  def value_sorted?
+    sorted_yaml = yaml.to_a.sort_by do |content| 
+      [content[1].downcase, content[0].downcase]
+    end
+
+    different_from_yaml? sorted_yaml
+  end
+
+  def different_from_yaml?(sorted_yaml)
+    actual_str   = enum_to_str(yaml)
+    expected_str = enum_to_str(sorted_yaml)
+
+    difference = Diffy::Diff.new(actual_str, expected_str).to_s
+
+    return if difference.empty?
+    
+    raise NotSortedError, "\n#{difference}"
+  end
+
+  def enum_to_str(enum)
+    enum.to_a.map { |x| x.join(' ') }.join("\n")
+  end
+end

spec/yaml_spec.rb

@@ -0,0 +1,38 @@
+require 'spec_helper'
+require 'support/yaml_sort_checker.rb'
+
+RSpec.describe 'Yaml files' do
+  let(:base_directory) { 'lib/yaml' }
+
+  describe 'file_aliases.yaml' do
+    let(:checker) { YamlSortChecker.new("#{base_directory}/file_aliases.yaml") }
+
+    it 'is sorted correctly' do
+      expect(checker.sorted?(:value)).to eq true
+    end
+  end
+
+  describe 'folder_aliases.yaml' do
+    let(:checker) { YamlSortChecker.new("#{base_directory}/folder_aliases.yaml") }
+
+    it 'is sorted correctly' do
+      expect(checker.sorted?(:value)).to eq true
+    end
+  end
+
+  describe 'folders.yaml' do
+    let(:checker) { YamlSortChecker.new("#{base_directory}/folders.yaml") }
+
+    it 'is sorted correctly' do
+      expect(checker.sorted?).to eq true
+    end
+  end
+
+  describe 'files.yaml' do
+    let(:checker) { YamlSortChecker.new("#{base_directory}/files.yaml") }
+
+    it 'is sorted correctly' do
+      expect(checker.sorted?).to eq true
+    end
+  end
+end