Update default Ruby version to 3.3.6

The latest Ruby is now 3.4.x. Our ideal default policy is to use the latest release of the prior year's version. This PR updates to the latest Ruby 3.3.x version which is 3.3.6.

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 
+- Default Ruby version is now 3.3.6 (https://github.com/heroku/heroku-buildpack-ruby/pull/1534)
 
 ## [v287] - 2024-12-25
 

Gemfile

@@ -1,7 +1,7 @@
 source "https://rubygems.org"
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-ruby '>= 3.1', '< 3.3'
+ruby "3.3.6"
 
 group :development, :test do
   gem "toml-rb"

Gemfile.lock

@@ -73,7 +73,7 @@ DEPENDENCIES
   toml-rb
 
 RUBY VERSION
-   ruby 3.1.6p260
+   ruby 3.3.6p260
 
 BUNDLED WITH
    2.5.11

buildpack.toml

@@ -1,6 +1,6 @@
 [buildpack]
 name = "Ruby"
-ruby_version = "3.1.6"
+ruby_version = "3.3.6"
 
 [publish.Ignore]
 files = [

changelogs/unreleased/default_ruby.md

@@ -0,0 +1,3 @@
+## Default Ruby version for new apps is now 3.3.6
+
+The [default Ruby version for new Ruby applications is 3.3.6](https://devcenter.heroku.com/articles/ruby-support#default-ruby-version-for-new-apps). You’ll only get the default if the application does not specify a ruby version.

lib/language_pack/ruby_version.rb

@@ -12,8 +12,8 @@ def initialize(output = "")
       end
     end
 
-    BOOTSTRAP_VERSION_NUMBER = "3.1.6".freeze
-    DEFAULT_VERSION_NUMBER = "3.1.6".freeze
+    BOOTSTRAP_VERSION_NUMBER = "3.3.6".freeze
+    DEFAULT_VERSION_NUMBER = "3.3.6".freeze
     DEFAULT_VERSION        = "ruby-#{DEFAULT_VERSION_NUMBER}".freeze
     LEGACY_VERSION_NUMBER  = "1.9.2".freeze
     LEGACY_VERSION         = "ruby-#{LEGACY_VERSION_NUMBER}".freeze

spec/helpers/outdated_ruby_version_spec.rb

@@ -19,11 +19,11 @@
     )
 
     outdated.call
-    expect(outdated.suggested_ruby_minor_version).to eq("3.1.6")
+    expect(outdated.suggested_ruby_minor_version).to eq("3.3.6")
   end
 
   it "handles arm 💪 architecture on heroku-24" do
-    ruby_version = LanguagePack::RubyVersion.new("ruby-3.1.0")
+    ruby_version = LanguagePack::RubyVersion.new("ruby-3.3.0")
     fetcher = LanguagePack::Fetcher.new(
       LanguagePack::Base::VENDOR_URL,
       stack: "heroku-24",
@@ -35,7 +35,7 @@
     )
 
     outdated.call
-    expect(outdated.suggested_ruby_minor_version).to eq("3.1.6")
+    expect(outdated.suggested_ruby_minor_version).to eq("3.3.6")
   end
 
   it "finds the latest version on a stack" do