v259 - re-release Ruby 3.3.0-preview2 and add tests (#1390)

* Test `bundle platform --ruby` conversion

The Ruby buildpack takes the output for `bundle platform --ruby` and converts that into a S3 url for download. This commit refactors that logic to make testing easier and adds tests for that conversion.

* v259

CHANGELOG.md

@@ -2,10 +2,14 @@
 
 ## Main (unreleased)
 
-## v258 (2023/09/26)
+## v259 (2023/10/02)
 
 - Ruby 3.3.0-preview2 is now available
 
+## v258 (2023/09/26)
+
+- No changes
+
 ## v257 (2023/09/20)
 
 - JRuby 9.3.11.0 is now available

lib/language_pack/helpers/bundler_wrapper.rb

@@ -142,10 +142,15 @@ def ruby_version
 
     # If there's a gem in the Gemfile (i.e. syntax error) emit error
     raise GemfileParseError.new(run("bundle check", user_env: true, env: env)) unless $?.success?
-    if output.match(/No ruby version specified/)
+
+    self.class.platform_to_version(output)
+  end
+
+  def self.platform_to_version(bundle_platform_output)
+    if bundle_platform_output.match(/No ruby version specified/)
       ""
     else
-      output.strip.sub('(', '').sub(')', '').sub(/(p-?\d+)/, ' \1').split.join('-')
+      bundle_platform_output.strip.sub('(', '').sub(')', '').sub(/(p-?\d+)/, ' \1').split.join('-')
     end
   end
 

lib/language_pack/version.rb

@@ -2,6 +2,6 @@
 
 module LanguagePack
   class LanguagePack::Base
-    BUILDPACK_VERSION = "v258"
+    BUILDPACK_VERSION = "v259"
   end
 end

spec/helpers/bundler_wrapper_spec.rb

@@ -1,7 +1,18 @@
 require 'spec_helper'
 
-describe "BundlerWrapper" do
+describe "Bundle platform conversion" do
+  it "converts `bundle platform --ruby` for prerelease versions" do
+    actual = LanguagePack::Helpers::BundlerWrapper.platform_to_version("ruby 3.3.0.preview2")
+    expect(actual).to eq("ruby-3.3.0.preview2")
+  end
+
+  it "converts `bundle platform --ruby` for released versions" do
+    actual = LanguagePack::Helpers::BundlerWrapper.platform_to_version("ruby 3.1.4")
+    expect(actual).to eq("ruby-3.1.4")
+  end
+end
 
+describe "BundlerWrapper" do
   before(:each) do
     if ENV['RUBYOPT']
       @original_rubyopt = ENV['RUBYOPT']