1 files changed, 88 insertions, 0 deletions
diff --git a/lib/rubygems/gem_runner.rb b/lib/rubygems/gem_runner.rb
new file mode 100644
index 0000000000..e60cebd0cb
--- /dev/null
+++ b/lib/rubygems/gem_runner.rb
@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+#--
+# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
+# All rights reserved.
+# See LICENSE.txt for permissions.
+#++
+
+require_relative "../rubygems"
+require_relative "command_manager"
+
+##
+# Run an instance of the gem program.
+#
+# Gem::GemRunner is only intended for internal use by RubyGems itself.  It
+# does not form any public API and may change at any time for any reason.
+#
+# If you would like to duplicate functionality of `gem` commands, use the
+# classes they call directly.
+
+class Gem::GemRunner
+  def initialize
+    @command_manager_class = Gem::CommandManager
+    @config_file_class = Gem::ConfigFile
+  end
+
+  ##
+  # Run the gem command with the following arguments.
+
+  def run(args)
+    validate_encoding args
+    build_args = extract_build_args args
+
+    do_configuration args
+
+    begin
+      Gem.load_env_plugins
+    rescue StandardError
+      nil
+    end
+    Gem.load_plugins
+
+    cmd = @command_manager_class.instance
+
+    cmd.command_names.each do |command_name|
+      config_args = Gem.configuration[command_name]
+      config_args = case config_args
+                    when String
+                      config_args.split " "
+                    else
+                      Array(config_args)
+      end
+      Gem::Command.add_specific_extra_args command_name, config_args
+    end
+
+    cmd.run Gem.configuration.args, build_args
+  end
+
+  ##
+  # Separates the build arguments (those following <code>--</code>) from the
+  # other arguments in the list.
+
+  def extract_build_args(args) # :nodoc:
+    return [] unless offset = args.index("--")
+
+    build_args = args.slice!(offset...args.length)
+
+    build_args.shift
+
+    build_args
+  end
+
+  private
+
+  def validate_encoding(args)
+    invalid_arg = args.find {|arg| !arg.valid_encoding? }
+
+    if invalid_arg
+      raise Gem::OptionParser::InvalidArgument.new("'#{invalid_arg.scrub}' has invalid encoding")
+    end
+  end
+
+  def do_configuration(args)
+    Gem.configuration = @config_file_class.new(args)
+    Gem.use_paths Gem.configuration[:gemhome], Gem.configuration[:gempath]
+    Gem::Command.extra_args = Gem.configuration[:gem]
+  end
+end