De-couple BundlerWrapper from LanguagePack::Ruby

lib/language_pack/helpers/bundler_wrapper.rb

@@ -1,5 +1,9 @@
 require 'language_pack/fetcher'
 
+# This class is responsible for installing and maintaining a
+# reference to bundler. It contains access to bundler internals
+# that are used to introspect a project such as detecting presence
+# of gems and their versions.
 class LanguagePack::Helpers::BundlerWrapper
   include LanguagePack::ShellHelpers
 
@@ -11,24 +15,20 @@ def initialize(error)
     end
   end
 
-  VENDOR_URL         = LanguagePack::Base::VENDOR_URL                # coupling
-  DEFAULT_FETCHER    = LanguagePack::Fetcher.new(VENDOR_URL)         # coupling
-  BUNDLER_DIR_NAME   = LanguagePack::Ruby::BUNDLER_GEM_PATH          # coupling
-  BUNDLER_PATH       = File.expand_path("../../../../tmp/#{BUNDLER_DIR_NAME}", __FILE__)
-  GEMFILE_PATH       = Pathname.new "./Gemfile"
-
-  attr_reader   :bundler_path
+  attr_reader :bundler_path
 
   def initialize(options = {})
-    @fetcher              = options[:fetcher]      || DEFAULT_FETCHER
+    @version              = "1.15.2"
     @bundler_tmp          = Dir.mktmpdir
-    @bundler_path         = options[:bundler_path] || File.join(@bundler_tmp, "#{BUNDLER_DIR_NAME}")
-    @gemfile_path         = options[:gemfile_path] || GEMFILE_PATH
-    @bundler_tar          = options[:bundler_tar]  || "#{BUNDLER_DIR_NAME}.tgz"
+    @fetcher              = options[:fetcher]      || LanguagePack::Fetcher.new(LanguagePack::Base::VENDOR_URL) # coupling
+    @bundler_path         = options[:bundler_path] || File.join(@bundler_tmp, "#{dir_name}")
+    @gemfile_path         = options[:gemfile_path] || Pathname.new("./Gemfile")
+    @bundler_tar          = options[:bundler_tar]  || "#{dir_name}.tgz"
+
     @gemfile_lock_path    = "#{@gemfile_path}.lock"
     @orig_bundle_gemfile  = ENV['BUNDLE_GEMFILE']
     ENV['BUNDLE_GEMFILE'] = @gemfile_path.to_s
-    @path                 = Pathname.new "#{@bundler_path}/gems/#{BUNDLER_DIR_NAME}/lib"
+    @path                 = Pathname.new "#{@bundler_path}/gems/#{dir_name}/lib"
   end
 
   def install
@@ -42,7 +42,7 @@ def clean
     ENV['BUNDLE_GEMFILE'] = @orig_bundle_gemfile
     FileUtils.remove_entry_secure(@bundler_tmp) if Dir.exist?(@bundler_tmp)
 
-    if LanguagePack::Ruby::BUNDLER_VERSION  == "1.7.12"
+    if version  == "1.7.12"
       # Hack to cleanup after pre 1.8 versions of bundler. See https://github.com/bundler/bundler/pull/3277/
       Dir["#{Dir.tmpdir}/bundler*"].each do |dir|
         FileUtils.remove_entry_secure(dir) if Dir.exist?(dir) && File.stat(dir).writable?
@@ -71,15 +71,19 @@ def windows_gemfile_lock?
   end
 
   def specs
-    @specs     ||= lockfile_parser.specs.each_with_object({}) {|spec, hash| hash[spec.name] = spec }
+    @specs ||= lockfile_parser.specs.each_with_object({}) {|spec, hash| hash[spec.name] = spec }
   end
 
   def platforms
     @platforms ||= lockfile_parser.platforms
   end
 
   def version
-    Bundler::VERSION
+    @version
+  end
+
+  def dir_name
+    "bundler-#{version}"
   end
 
   def instrument(*args, &block)
@@ -89,7 +93,7 @@ def instrument(*args, &block)
   def ruby_version
     instrument 'detect_ruby_version' do
       env = { "PATH"     => "#{bundler_path}/bin:#{ENV['PATH']}",
-              "RUBYLIB"  => File.join(bundler_path, "gems", BUNDLER_DIR_NAME, "lib"),
+              "RUBYLIB"  => File.join(bundler_path, "gems", dir_name, "lib"),
               "GEM_PATH" => "#{bundler_path}:#{ENV["GEM_PATH"]}",
               "BUNDLE_DISABLE_VERSION_CHECK" => "true"
             }

lib/language_pack/ruby.rb

@@ -16,8 +16,6 @@ class LanguagePack::Ruby < LanguagePack::Base
   NAME                 = "ruby"
   LIBYAML_VERSION      = "0.1.7"
   LIBYAML_PATH         = "libyaml-#{LIBYAML_VERSION}"
-  BUNDLER_VERSION      = "1.15.2"
-  BUNDLER_GEM_PATH     = "bundler-#{BUNDLER_VERSION}"
   RBX_BASE_URL         = "http://binaries.rubini.us/heroku"
   NODE_BP_PATH         = "vendor/node/bin"
 
@@ -126,9 +124,9 @@ def config_detect
   def warn_bundler_upgrade
     old_bundler_version  = @metadata.read("bundler_version").chomp if @metadata.exists?("bundler_version")
 
-    if old_bundler_version && old_bundler_version != BUNDLER_VERSION
+    if old_bundler_version && old_bundler_version != bundler.version
       puts(<<-WARNING)
-Your app was upgraded to bundler #{ BUNDLER_VERSION }.
+Your app was upgraded to bundler #{ bundler.version }.
 Previously you had a successful deploy with bundler #{ old_bundler_version }.
 
 If you see problems related to the bundler version please refer to:
@@ -596,7 +594,7 @@ def bundler_binstubs_path
   end
 
   def bundler_path
-    @bundler_path ||= "#{slug_vendor_base}/gems/#{BUNDLER_GEM_PATH}"
+    @bundler_path ||= "#{slug_vendor_base}/gems/#{bundler.dir_name}"
   end
 
   def write_bundler_shim(path)
@@ -607,7 +605,7 @@ def write_bundler_shim(path)
 #!/usr/bin/env ruby
 require 'rubygems'
 
-version = "#{BUNDLER_VERSION}"
+version = "#{bundler.version}"
 
 if ARGV.first
   str = ARGV.first
@@ -678,7 +676,7 @@ def build_bundler(default_bundle_without)
           yaml_include   = File.expand_path("#{libyaml_dir}/include").shellescape
           yaml_lib       = File.expand_path("#{libyaml_dir}/lib").shellescape
           pwd            = Dir.pwd
-          bundler_path   = "#{pwd}/#{slug_vendor_base}/gems/#{BUNDLER_GEM_PATH}/lib"
+          bundler_path   = "#{pwd}/#{slug_vendor_base}/gems/#{bundler.dir_name}/lib"
           # we need to set BUNDLE_CONFIG and BUNDLE_GEMFILE for
           # codon since it uses bundler.
           env_vars       = {
@@ -1081,7 +1079,7 @@ def load_bundler_cache
       FileUtils.mkdir_p(heroku_metadata)
       @metadata.write(ruby_version_cache, full_ruby_version, false)
       @metadata.write(buildpack_version_cache, BUILDPACK_VERSION, false)
-      @metadata.write(bundler_version_cache, BUNDLER_VERSION, false)
+      @metadata.write(bundler_version_cache, bundler.version, false)
       @metadata.write(rubygems_version_cache, rubygems_version, false)
       @metadata.write(stack_cache, @stack, false)
       @metadata.save

spec/helpers/fetcher_spec.rb

@@ -1,15 +1,14 @@
 require 'spec_helper'
 
 describe "Fetches" do
-
   it "bundler" do
     Dir.mktmpdir do |dir|
       Dir.chdir(dir) do
+
         fetcher = LanguagePack::Fetcher.new(LanguagePack::Base::VENDOR_URL)
-        fetcher.fetch_untar("#{LanguagePack::Ruby::BUNDLER_GEM_PATH}.tgz")
+        fetcher.fetch_untar("#{LanguagePack::Helpers::BundlerWrapper.new.dir_name}.tgz")
         expect(`ls bin`).to match("bundle")
       end
     end
   end
 end
-