Add Next Gemfile Support

Closes #1

bin/build

@@ -8,9 +8,12 @@ APP_DIR=$(pwd)
 BIN_DIR=$(cd $(dirname $0); pwd)
 BUILDPACK_DIR=$(dirname $BIN_DIR)
 
-# legacy buildpack uses $STACK 
+# legacy buildpack uses $STACK
 export STACK=$CNB_STACK_ID
 
+echo "-----> build JUAN"
+printenv
+
 source "$BIN_DIR/support/bash_functions.sh"
 heroku_buildpack_ruby_install_ruby "$BIN_DIR" "$BUILDPACK_DIR"
 

bin/compile

@@ -7,6 +7,7 @@ CACHE_DIR=$2
 ENV_DIR=$3
 BIN_DIR=$(cd $(dirname $0); pwd)
 BUILDPACK_DIR=$(dirname $BIN_DIR)
+echo "-----> compile JUAN"
 
 source "$BIN_DIR/support/bash_functions.sh"
 heroku_buildpack_ruby_install_ruby "$BIN_DIR" "$BUILDPACK_DIR"

bin/support/ruby_compile

@@ -13,6 +13,7 @@ require "language_pack/shell_helpers"
 
 begin
   LanguagePack::ShellHelpers.initialize_env(ARGV[2])
+  puts "RUBY_COMPILE: #{ARGV.inspect}"
   if pack = LanguagePack.detect(ARGV[0], ARGV[1])
     pack.topic("Compiling #{pack.name}")
     pack.log("compile") do

lib/language_pack/helpers/bundler_wrapper.rb

@@ -101,7 +101,7 @@ def initialize(version_hash, major_minor)
   def initialize(options = {})
     @bundler_tmp          = Pathname.new(Dir.mktmpdir)
     @fetcher              = options[:fetcher]      || LanguagePack::Fetcher.new(LanguagePack::Base::VENDOR_URL) # coupling
-    @gemfile_path         = options[:gemfile_path] || Pathname.new("./Gemfile")
+    @gemfile_path         = options[:gemfile_path] || Pathname.new(ENV["BUNDLE_GEMFILE"] || "./Gemfile")
     @gemfile_lock_path    = Pathname.new("#{@gemfile_path}.lock")
 
     @version = self.class.detect_bundler_version(contents: @gemfile_lock_path.read(mode: "rt"))
@@ -114,7 +114,9 @@ def initialize(options = {})
   end
 
   def install
+    warn("install start #{ENV['BUNDLE_GEMFILE']} #{env('BUNDLE_GEMFILE')}")
     ENV['BUNDLE_GEMFILE'] = @gemfile_path.to_s
+    warn("install end #{ENV['BUNDLE_GEMFILE']} #{env('BUNDLE_GEMFILE')}")
 
     fetch_bundler
     $LOAD_PATH << @path
@@ -123,7 +125,9 @@ def install
   end
 
   def clean
+    warn("clean start #{ENV['BUNDLE_GEMFILE']} #{env('BUNDLE_GEMFILE')}")
     ENV['BUNDLE_GEMFILE'] = @orig_bundle_gemfile
+    warn("clean end #{ENV['BUNDLE_GEMFILE']} #{env('BUNDLE_GEMFILE')}")
     @bundler_tmp.rmtree if @bundler_tmp.directory?
   end
 
@@ -223,7 +227,7 @@ def needs_ruby_global_append_path?
   end
 
   def bundler_version_escape_valve!
-    topic("Removing BUNDLED WITH version in the Gemfile.lock")
+    topic("Removing BUNDLED WITH version in the #{@gemfile_lock_path}")
     contents = File.read(@gemfile_lock_path, mode: "rt")
     File.open(@gemfile_lock_path, "w") do |f|
       f.write contents.sub(/^BUNDLED WITH$(\r?\n)   (?<major>\d+)\.\d+\.\d+/m, '')

lib/language_pack/ruby.rb

@@ -29,13 +29,26 @@ def self.use?
   end
 
   def self.bundler
+    warn("setting bundler #{env('BUNDLER_ORIG_BUNDLE_GEMFILE')} #{env('BUNDLE_GEMFILE')}", inline: true)
     @@bundler ||= LanguagePack::Helpers::BundlerWrapper.new.install
   end
 
   def bundler
     self.class.bundler
   end
 
+  def current_gemfile
+    ENV["BUNDLE_GEMFILE"] || "Gemfile"
+  end
+
+  def gemfile_path
+    Pathname.new(current_gemfile)
+  end
+
+  def gemfile_lock_path
+    Pathname.new("#{current_gemfile}.lock")
+  end
+
   def initialize(*args)
     super(*args)
     @fetchers[:mri]    = LanguagePack::Fetcher.new(VENDOR_URL, @stack)
@@ -144,7 +157,7 @@ def build
       build_bundler
       # TODO post_bundler might need to be done in a new layer
       bundler.clean
-      gem_layer.metadata[:gems] = Digest::SHA2.hexdigest(File.read("Gemfile.lock"))
+      gem_layer.metadata[:gems] = Digest::SHA2.hexdigest(File.read(gemfile_lock_path))
       gem_layer.metadata[:stack] = @stack
       gem_layer.metadata[:ruby_version] = run_stdout(%q(ruby -v)).strip
       gem_layer.metadata[:rubygems_version] = run_stdout(%q(gem -v)).strip
@@ -779,7 +792,7 @@ def build_bundler
       if bundler.windows_gemfile_lock?
         log("bundle", "has_windows_gemfile_lock")
 
-        File.unlink("Gemfile.lock")
+        File.unlink(gemfile_lock_path)
         ENV.delete("BUNDLE_DEPLOYMENT")
 
         warn(<<~WARNING, inline: true)
@@ -816,7 +829,7 @@ def build_bundler
 
         # we need to set BUNDLE_CONFIG and BUNDLE_GEMFILE for
         # codon since it uses bundler.
-        env_vars["BUNDLE_GEMFILE"] = "#{pwd}/Gemfile"
+        env_vars["BUNDLE_GEMFILE"] = "#{pwd}/#{gemfile_path}"
         env_vars["BUNDLE_CONFIG"] = "#{pwd}/.bundle/config"
         env_vars["CPATH"] = noshellescape("#{yaml_include}:$CPATH")
         env_vars["CPPATH"] = noshellescape("#{yaml_include}:$CPPATH")

lib/language_pack/shell_helpers.rb

@@ -54,6 +54,7 @@ def self.blacklist?(key)
 
     def self.initialize_env(path)
       env_dir = Pathname.new("#{path}")
+      puts "self.initialize_env: #{env_dir}"
       if env_dir.exist? && env_dir.directory?
         env_dir.each_child do |file|
           key   = file.basename.to_s