Merge RubyGems-3.3.0 and Bundler-2.3.0

1 files changed, 73 insertions, 0 deletions

diff --git a/lib/bundler/self_manager.rb b/lib/bundler/self_manager.rb
new file mode 100644
index 0000000000..bda2eb51f3
--- /dev/null
+++ b/lib/bundler/self_manager.rb
@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+module Bundler
+  #
+  # This class handles installing and switching to the version of bundler needed
+  # by an application.
+  #
+  class SelfManager
+    def restart_with_locked_bundler_if_needed
+      return unless needs_switching? && installed?
+
+      restart_with_locked_bundler
+    end
+
+    def install_locked_bundler_and_restart_with_it_if_needed
+      return unless needs_switching?
+
+      Bundler.ui.info \
+        "Bundler #{current_version} is running, but your lockfile was generated with #{lockfile_version}. " \
+        "Installing Bundler #{lockfile_version} and restarting using that version."
+
+      install_and_restart_with_locked_bundler
+    end
+
+    private
+
+    def install_and_restart_with_locked_bundler
+      bundler_dep = Gem::Dependency.new("bundler", lockfile_version)
+
+      Gem.install(bundler_dep)
+    rescue StandardError => e
+      Bundler.ui.trace e
+      Bundler.ui.warn "There was an error installing the locked bundler version (#{lockfile_version}), rerun with the `--verbose` flag for more details. Going on using bundler #{current_version}."
+    else
+      restart_with_locked_bundler
+    end
+
+    def restart_with_locked_bundler
+      configured_gem_home = ENV["GEM_HOME"]
+      configured_gem_path = ENV["GEM_PATH"]
+
+      Bundler.with_original_env do
+        Kernel.exec(
+          { "GEM_HOME" => configured_gem_home, "GEM_PATH" => configured_gem_path, "BUNDLER_VERSION" => lockfile_version },
+          $PROGRAM_NAME, *ARGV
+        )
+      end
+    end
+
+    def needs_switching?
+      ENV["BUNDLER_VERSION"].nil? &&
+        Bundler.rubygems.supports_bundler_trampolining? &&
+        SharedHelpers.in_bundle? &&
+        lockfile_version &&
+        !lockfile_version.end_with?(".dev") &&
+        lockfile_version != current_version
+    end
+
+    def installed?
+      Bundler.configure
+
+      Bundler.rubygems.find_bundler(lockfile_version)
+    end
+
+    def current_version
+      @current_version ||= Bundler::VERSION
+    end
+
+    def lockfile_version
+      @lockfile_version ||= Bundler::LockfileParser.bundled_with
+    end
+  end
+end