For funsies: Crystal implementation

.gitignore

@@ -6,5 +6,6 @@
 /pkg/
 /spec/reports/
 /tmp/
+/crystal_build/
 
 Gemfile.lock

.travis.yml

@@ -1,6 +1,11 @@
 ---
 language: ruby
 cache: bundler
+# ref: https://github.com/travis-ci/travis-build/blob/543bb7e3/lib/travis/build/script/crystal.rb#L104-L108
+before_script:
+  - travis_apt_get_update
+  - sudo apt-get install -y gcc pkg-config git tzdata libpcre3-dev libevent-dev libyaml-dev libgmp-dev libssl-dev libxml2-dev 2>&1 > /dev/null
+  - sudo snap install crystal --classic --channel=latest/stable
 rvm:
 - 2.5
 - 2.6

Rakefile

@@ -1,10 +1,23 @@
 require "bundler/gem_tasks"
 require "rake/testtask"
+require "rake/clean"
+
+CLEAN << "crystal_build"
 
 Rake::TestTask.new(:test) do |t|
   t.libs << "test"
   t.libs << "lib"
   t.test_files = FileList["test/**/*_test.rb"]
 end
 
-task :default => :test
+namespace :crystal do
+  directory "crystal_build"
+  file      "crystal_build/cfme-versions" => "crystal_build" do
+    sh "crystal build --release lib/cfme-versions.cr -o crystal_build/cfme-versions"
+  end
+
+  desc "Build the crystal "
+  task :build => "crystal_build/cfme-versions"
+end
+
+task :default => ["crystal:build", :test]

lib/cfme-versions.cr

@@ -0,0 +1,92 @@
+module CFME
+  class Versions
+    FIELDS   = [
+         "ManageIQ",      "",       "CFME",  "CloudForms", "CP4MCM", "Ruby", "Rails", "PostgreSQL"
+    ]
+    VERSIONS = [
+      %w[ N/A             N/A        5.1.z    2.0           N/A       N/A     N/A      N/A        ],
+      %w[ N/A             N/A        5.2.z    3.0           N/A       N/A     N/A      N/A        ],
+      %w[ Anand           1.y.z      5.3.z    3.1           N/A       N/A     N/A      N/A        ],
+      %w[ Botvinnik       2.y.z      5.4.z    3.2           N/A       N/A     N/A      N/A        ],
+      %w[ Capablanca      3.y.z      5.5.z    4.0           N/A       2.2.z   4.2.z    9.4.z      ],
+      %w[ Darga           4.y.z      5.6.z    4.1           N/A       2.2.z   5.0.z    9.4.z      ],
+      %w[ Euwe            5.y.z      5.7.z    4.2           N/A       2.3.z   5.0.z    9.5.z      ],
+      %w[ Fine            6.y.z      5.8.z    4.5           N/A       2.3.z   5.0.z    9.5.z      ],
+      %w[ Gaprindashvili  7.y.z      5.9.z    4.6           N/A       2.3.z   5.0.z    9.5.z      ],
+      %w[ Hammer          8.y.z      5.10.z   4.7           N/A       2.4.z   5.0.z    9.5.z      ],
+      %w[ Ivanchuk        9.y.z      5.11.z   5.0           1.2,1.3   2.5.z   5.1.z    10.y       ],
+      %w[ Jansa           10.y.z     N/A      N/A           2.0       2.5.z   5.2.z    10.y       ],
+      %w[ Kasparov        11.y.z     N/A      N/A           N/A       2.6.z   5.2.z    10.y       ]
+    ]
+
+    def self.run(argv = ARGV)
+      until argv.empty?
+        arg = argv.shift
+
+        # The `return` statements are there for specs
+        case arg
+        when "--version"  then return print_version
+        when "--help"     then return print_help
+        end
+      end
+
+      CFME::Versions.print_table
+    end
+
+    def self.version
+      VERSIONS.last[1].split(".").first + ".0.0"
+    end
+
+    def self.print_help
+      puts <<-HELP + "\n\n"
+      usage:  cfme-versions [OPTION]...
+
+      Options:
+
+          --version     Prints the version number and exits
+          --help        This help
+      HELP
+      exit
+    end
+
+    def self.print_table
+      # Print Header
+      puts printable_row(FIELDS)
+      puts printable_row(spacings.map { |size| "-" * size })
+
+      # Print version data
+      VERSIONS.each do |version|
+        version_data = version.map { |column| column == "N/A" ? "" : column } # remove N/A values
+        puts printable_row(version_data)
+      end
+    end
+
+    def self.print_version
+      puts CFME::Versions.version
+      exit
+    end
+
+    private def self.printable_row(data)
+      "| #{data.map_with_index { |header, index| header.ljust(spacings[index]) }.join(" | ")} |"
+    end
+
+    @@spacings = [] of Int32
+
+    # Column width based on Miq::Versions.raw_data
+    private def self.spacings
+      spacings = @@spacings
+      return spacings unless spacings.empty?
+
+      spacings = FIELDS.map(&.size)
+      VERSIONS.each do |version|
+        version.each.with_index do |col, index|
+          spacings[index] = [spacings[index].to_i, col.size].max
+        end
+      end
+
+      @@spacings = spacings
+    end
+  end
+end
+
+CFME::Versions.run

test/crystal_implementation_test.rb

@@ -0,0 +1,22 @@
+require "test_helper"
+
+class CrystalImplementation < Minitest::Test
+  def cfme_versions_cr *args
+    `crystal_build/cfme-versions #{args.join " "}`
+  end
+
+  def test_output_is_correct
+    expected, _ = capture_io { CFME::Versions.print_help }
+    assert_equal expected, cfme_versions_cr('--help')
+  end
+
+  def test_version_flag_is_correct
+    expected, _ = capture_io { CFME::Versions.print_version }
+    assert_equal expected, cfme_versions_cr('--version')
+  end
+
+  def test_help_text_is_correct
+    expected, _ = capture_io { CFME::Versions.print_table }
+    assert_equal expected, cfme_versions_cr
+  end
+end