executable.rb in packer-binary-0.2.0

- old
+ new

@@ -1,39 +1,57 @@
 module Packer
   module Binary
+    # This class handles downloading, extracting, and saving the associated
+    # binary file
     class Executable
       include Packer::Binary::Helpers
 
+      # Raised when the current platform is unsupported
+      class PlatformUnsupported < StandardError; end
+
+      # The download URI for the binary package
+      PACKER_DOWNLOAD_URI = 'releases.hashicorp.com'.freeze
+
+      # Loads global config values and creates the download directory if the
+      # current platform is supported
       def initialize
         @packer_version = Packer::Binary.config.version
         @download_path = "#{Packer::Binary.config.download_path.chomp('/')}/packer-binary/#{@packer_version}/bin"
         @download_filename = "#{@packer_version}-packer.zip"
 
         FileUtils.mkdir_p @download_path
 
-        raise 'Your OS is not supported' unless supported?
+        raise PlatformUnsupported unless supported?
       end
 
+      # Returns the path to the binary if it exists
+      # @return [String] absolute path of the binary
       def binary
         Dir["#{@download_path}/packer*"][0]
       end
 
+      # Downloads the zipfile from the origin
       def download
-        return "#{binary} already exists" if binary_exist?
+        return if binary_exist?
 
         msg("Downloading https://#{download_domain}/#{download_uri}")
 
         require 'open-uri'
 
-        File.open("#{@download_path}/#{@download_filename}", "wb") do |saved_file|
+        File.open("#{@download_path}/#{@download_filename}", 'wb') do |saved_file|
           # the following "open" is provided by open-uri
-          open("https://#{download_domain}/#{download_uri}", "rb") do |read_file|
+          open("https://#{download_domain}/#{download_uri}", 'rb') do |read_file|
             saved_file.write(read_file.read)
           end
         end
+      end
 
-        extract
+      # Extracts the binary from the zipfile and makes it executable
+      def extract
+        return if binary_exist?
+
+        Compressor.extract("#{@download_path}/#{@download_filename}", @download_path)
         make_exe
       end
 
       private
 
@@ -47,23 +65,18 @@
 
       def make_exe
         FileUtils.chmod('a+x', binary) if binary_exist?
       end
 
-      def extract
-        Compressor::extract("#{@download_path}/#{@download_filename}", @download_path)
-      end
-
       def download_uri
         "packer/#{@packer_version}/packer_#{@packer_version}_freebsd_amd64.zip" if OS.freebsd?
         "packer/#{@packer_version}/packer_#{@packer_version}_darwin_amd64.zip" if OS.mac?
         "packer/#{@packer_version}/packer_#{@packer_version}_windows_amd64.zip" if OS.windows?
         "packer/#{@packer_version}/packer_#{@packer_version}_linux_amd64.zip" if OS.linux?
       end
 
       def download_domain
-        'releases.hashicorp.com'
+        PACKER_DOWNLOAD_URI
       end
-
     end
   end
 end